# Hvac not working correctly HEAT blowing out alot of moisture



## superdutypsd (Oct 30, 2014)

Anyone good with ac hvac on these truck 2007 6.0 f350 in summer i vac down my system and recharged my truck runs and idles 10-12 aday, the ac would work for a few hours then cut out i would get out and tap the clutch to rengage the ac, now with heat on its blowing out alot of moisture, the heat works but you can feel the humidity in thr cab and the deforst actually ends up fogging up the windows more at first. What do i need to fix for dry air again


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## Randall Ave (Oct 29, 2014)

There should be a drain for the moisture. Does it smell like antifreeze?


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## FredG (Oct 15, 2012)

Possibly the start of heater core. Check and see if there is any moisture around passenger side floor area.


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## superdutypsd (Oct 30, 2014)

Randall Ave;2052827 said:


> There should be a drain for the moisture. Does it smell like antifreeze?


Were can i find this at


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## superdutypsd (Oct 30, 2014)

FredG;2052836 said:


> Possibly the start of heater core. Check and see if there is any moisture around passenger side floor area.


No moisture around floor, all dry


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## superdutypsd (Oct 30, 2014)

My low side is cycling between 25-55 and high side cycling between 100-125, anyone no what it should be high and low and i do not smell any coolant


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## Nero (Aug 10, 2009)

I think you have a bad heater core.
As far is your ac, that is a totally separate issue.


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## superdutypsd (Oct 30, 2014)

Nero;2052910 said:


> I think you have a bad heater core.
> As far is your ac, that is a totally separate issue.


But with the moisture in the heat, and ac cuting out some times, this could be from a bad evap, i know the heat comes from coolant and ac from ac system but i thought the evap drys the air for both systems


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## superdutypsd (Oct 30, 2014)

Were is the heater core located on these trucks anyway to test them, im half temped to just replace everything i have 9200 hours on the engine and 325,000 miles owned since new 2007


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## Nero (Aug 10, 2009)

superdutypsd;2052913 said:


> But with the moisture in the heat, and ac cuting out some times, this could be from a bad evap, i know the heat comes from coolant and ac from ac system but i thought the evap drys the air for both systems


First of all, Unplug your compressor pump and see if you still have the issue.


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## LapeerLandscape (Dec 29, 2012)

Nero;2052971 said:


> First of all, Unplug your compressor pump and see if you still have the issue.


That's what I was going to suggest, unplug the A/C comp out at the clutch.


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## superdutypsd (Oct 30, 2014)

When im at idle ac works fine but the clutch will then disengage high side reading 210 and low side reading 25/30 when the compressor shuts off the low side goes up to 65 and high side drops down to 75, if i get out and tap the clutch it will engage the ac, if im doing 75mph ac will work as usual. With heat on i do not hear the ac compressor cycling, i was told that the evap, is also used for the heat not just for the ac, i do not know if this is true, i just know basic basic ac hvac on cars and trucks


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## tjctransport (Nov 22, 2008)

ac compressor engages for defrost, not for heat.


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## superdutypsd (Oct 30, 2014)

tjctransport;2052995 said:


> ac compressor engages for defrost, not for heat.


Ok yes i do remember hearing it with defrost on, could my evap be going bad or could the moisture be from the clutch not engaging on the ac when defrost is on


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## Whiffyspark (Dec 23, 2009)

Your clutch shouldn't be cycling with it on. You need to have a proper charge put in and then go from there. Pressures don't mean much 

The Windows fogging is usually sign of heater core going. None of this has to do with evap


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## FredG (Oct 15, 2012)

superdutypsd;2052915 said:


> Were is the heater core located on these trucks anyway to test them, im half temped to just replace everything i have 9200 hours on the engine and 325,000 miles owned since new 2007


If you do diagnose it to a heater core, Your suggestion on replacing the high mile truck might be a good idea. Heater cores are expensive and labor intensive. should be located behind the dash.


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## Randall Ave (Oct 29, 2014)

If you let it sit and run with the A/C on, does it drip water like it should? 
There is nothing wrong with the evaporator. The drain is plugged, should be at bottom of heater box. If the drain is fine, replace the heater core, not that bad to do. 
But with that many miles, she'd be down the road.


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## superdutypsd (Oct 30, 2014)

FredG;2053060 said:


> If you do diagnose it to a heater core, Your suggestion on replacing the high mile truck might be a good idea. Heater cores are expensive and labor intensive. should be located behind the dash.


I was refering to the heater and ac units, i have a new truck i order from ford thats suppose to be delivered after winter and i will keep this as a work truck, as far as the repair i have the tools and can do myself i have pulled my cab twice amd tore the motor down twice, i have high miles but the body and motor are in great shape really, and mostlike highway miles i do 300 a day and 80-100k a year


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## superdutypsd (Oct 30, 2014)

Whiffyspark;2053021 said:


> Your clutch shouldn't be cycling with it on. You need to have a proper charge put in and then go from there. Pressures don't mean much
> 
> The Windows fogging is usually sign of heater core going. None of this has to do with evap


The system has the proper charge and was vaccum down to -30 and held for 45 min before recharging to proper weight


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## superdutypsd (Oct 30, 2014)

Randall Ave;2053083 said:


> If you let it sit and run with the A/C on, does it drip water like it should?
> There is nothing wrong with the evaporator. The drain is plugged, should be at bottom of heater box. If the drain is fine, replace the heater core, not that bad to do.
> But with that many miles, she'd be down the road.


 Yes theres a puddle under truck when ac is on, i guess i will replace the heat core and ac clutch and see how things go from there, this truck did a 100k miles from this time last year, like to get another year or two out of it as a work truck before replacing, as i aready have a new one coming in a few months from ford


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## superdutypsd (Oct 30, 2014)

Thanks you everyone so far i will replace heat core and ac clutch and go and see if it fixes and let know what it was, as of now the heat still works great as it should so no hurry


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## superdutypsd (Oct 30, 2014)

Whiffyspark;2053021 said:


> Your clutch shouldn't be cycling with it on. You need to have a proper charge put in and then go from there. Pressures don't mean much
> 
> The Windows fogging is usually sign of heater core going. None of this has to do with evap


My compressor cycles in defrost, should it not


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## Randall Ave (Oct 29, 2014)

superdutypsd;2053096 said:


> Thanks you everyone so far i will replace heat core and ac clutch and go and see if it fixes and let know what it was, as of now the heat still works great as it should so no hurry


Just replace the heater core, leave the A/C alone. One is not affecting the other.


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## superdutypsd (Oct 30, 2014)

A heater core is 50 dollars and located at the bottom floor at passager feet and half way behind glove box might tackle this this weekend to see if it does anything


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## FredG (Oct 15, 2012)

superdutypsd;2053084 said:


> I was refering to the heater and ac units, i have a new truck i order from ford thats suppose to be delivered after winter and i will keep this as a work truck, as far as the repair i have the tools and can do myself i have pulled my cab twice amd tore the motor down twice, i have high miles but the body and motor are in great shape really, and mostlike highway miles i do 300 a day and 80-100k a year


I'm cool I'm fine with reconditioning. I don't have that talent. Did not know you had it apart and been working on it. You say you do 300 day you also quoted it was new when you acquired it. The truck should have 800k on it.

You appear that 325k is not a lot of miles to you.


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## superdutypsd (Oct 30, 2014)

FredG;2053150 said:


> I'm cool I'm fine with reconditioning. I don't have that talent. Did not know you had it apart and been working on it. You say you do 300 day you also quoted it was new when you acquired it. The truck should have 800k on it.
> 
> You appear that 325k is not a lot of miles to you.


O dnt get me wrong 325k is alot of miles, i guess just trying to covey its mostly highway not hard beaten miles, i cycle my personal trucks into work trucks, so iv had this truck new since 07 at which i used as a personal truck till 2012 at which time i moved it to oone of my work trucks and i think it had around 33k miles on it so from 12 to current went from 33k to 325k and no the new truck i order willbe use for personal the in a few year it willbecome a work one and replace this one unless i buy a newer one for work to replace this, if you get what im trying to say


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## FredG (Oct 15, 2012)

superdutypsd;2053110 said:


> A heater core is 50 dollars and located at the bottom floor at passager feet and half way behind glove box might tackle this this weekend to see if it does anything


$50.00 that's cheap. I'm glad this is something you can do yourself.


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## superdutypsd (Oct 30, 2014)

I also try to keep very good care of of my equipment and fairly up todate, as i think it tend to think it says alot about your company and as an individual, also like to get my moneys worth, dont have money to be throwing away and buying new toys every year, take care of your tools, and your tools will take care of you


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## superdutypsd (Oct 30, 2014)

Randall Ave;2053106 said:


> Just replace the heater core, leave the A/C alone. One is not affecting the other.


Will do, i guess i got confused i had someone on another forum tell me that my problem was probably steming from the ac side causing both the ac and the moisture in the heat, thanks man


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## 1olddogtwo (Aug 6, 2007)

If the truck is not losing coolant and no obvious signs of coolant leaking in the cab, how does that justify replacing the heater core?

My guess is the box has water leaking in and is collecting.


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## LapeerLandscape (Dec 29, 2012)

Can you do a coolant pressure test and see if it leaks down.


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## rjigto4oje (Oct 27, 2010)

A bad heater core will smell like maple syrup. Heres a suggestion, bypass the heater core ,and see it the problem is gone. If so the put a core in it. Keep us posted.


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## superdutypsd (Oct 30, 2014)

1olddogtwo;2053184 said:


> If the truck is not losing coolant and no obvious signs of coolant leaking in the cab, how does that justify replacing the heater core?
> 
> My guess is the box has water leaking in and is collecting.


Well thats what i am trying to figure out, i do not have the symptoms of a bad heater core, or evap, the only thing happening is the ac clutch disengaging which causeing the ac to cut in and ouf and when i turn my defrost on or heat im getting humid heat or moisture in it, one person telling me its the ac side causing the moisture and not drying the air and others saying its heater core


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## superdutypsd (Oct 30, 2014)

LapeerLandscape;2053196 said:


> Can you do a coolant pressure test and see if it leaks down.


I know my coolant isnt leaking as i keep up one my maintance religious and monitor coolant level, be we are talking about fords wonder child here a 6.0 powerstroke lol, i also monitor all the pids of the truck specifically EOT Vs ECT, injection pressure, and trans temp, voltage


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## superdutypsd (Oct 30, 2014)

rjigto4oje;2053202 said:


> A bad heater core will smell like maple syrup. Heres a suggestion, bypass the heater core ,and see it the problem is gone. If so the put a core in it. Keep us posted.


Theres no smells of coolant or anything sweet, would the heat still work with bad heater core, do you think i have to issues going on here, one the ac cutting in and out at times, and two moisture in the defrost and heat


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## Whiffyspark (Dec 23, 2009)

The ac has a cycling switch on the accumulator I think on that truck. Try swapping the relay for the clutch and also wiggle the wiring on the ac compressor 

Does the compressor stay on the whole time when you have the ac on?


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## rjigto4oje (Oct 27, 2010)

If it doesn't smell and does leak. Then let's dig a litte deeper, can you tell if the recirc works on the truck, maybe it pulling outside air all of the time. Without reading back is the a/c drain clear.


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## superdutypsd (Oct 30, 2014)

Whiffyspark;2053243 said:


> The ac has a cycling switch on the accumulator I think on that truck. Try swapping the relay for the clutch and also wiggle the wiring on the ac compressor
> 
> Does the compressor stay on the whole time when you have the ac on?


No when i first turn ac on it will engage, then disengage maybe 10min later and if i get out and tap the clutch the ac will enage and disengage unless i start driving it will stay in i think the high side pressure is getting to high or pressure switch going bad


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## superdutypsd (Oct 30, 2014)

rjigto4oje;2053247 said:


> If it doesn't smell and does leak. Then let's dig a litte deeper, can you tell if the recirc works on the truck, maybe it pulling outside air all of the time. Without reading back is the a/c drain clear.


Yes ac drain clear


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## rjigto4oje (Oct 27, 2010)

I understand. Does the recirc work on the truck. It could be pulling outside air, all of the time


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## FredG (Oct 15, 2012)

1olddogtwo;2053184 said:


> If the truck is not losing coolant and no obvious signs of coolant leaking in the cab, how does that justify replacing the heater core?
> 
> My guess is the box has water leaking in and is collecting.


It doesn't if no moisture in cab on floor under glove box not likely.


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## superdutypsd (Oct 30, 2014)

rjigto4oje;2053266 said:


> I understand. Does the recirc work on the truck. It could be pulling outside air, all of the time


Im pretty sure it is, all of this started happening when i pulled the cab, to do head gaskets, i had to dump the ac, when done, I vaccum down to about -28 and let stay for 45 min to make sure system was sealed, i them recharged, with my gagues on at idle the low is 35 and high 210, at which point the clutch disengages and low side goes to 65 and high goes down to 75. So i do not know if this is being case by high side pressure geting to high and switch kicking in to disengage clutch or what


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## rjigto4oje (Oct 27, 2010)

How warm and humid was it when you did the recharge. Maybe its over charged . Have you ever washed the condensor as you may have stated tou drive on the highway alot. If its over charged it will cycle too


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## superdutypsd (Oct 30, 2014)

rjigto4oje;2053300 said:


> How warm and humid was it when you did the recharge. Maybe its over charged . Have you ever washed the condensor as you may have stated tou drive on the highway alot. If its over charged it will cycle too


Never washed condenser before and i will try to see what for high and low specs are tomarrow


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## Whiffyspark (Dec 23, 2009)

You didn't charge it with a scale just by gauges, correct?

You're not going to find specs for psi. It's irreverent 95% of the time


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## rjigto4oje (Oct 27, 2010)

Let us know what happens. If need be I'll pm you my number


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## superdutypsd (Oct 30, 2014)

Whiffyspark;2053378 said:


> You didn't charge it with a scale just by gauges, correct?
> 
> You're not going to find specs for psi. It's irreverent 95% of the time


I recharge in accordance with the spec under the hood by weight and oz


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## superdutypsd (Oct 30, 2014)

rjigto4oje;2053382 said:


> Let us know what happens. If need be I'll pm you my number


I am going to try to clean the condensor before its to cold out, also was know sometimes you need to clean coils up in evap core, im gonn poke around thinweekend trying to figure it ouf as i want get this humid heat fined before snowfall because i know with moisture coming out defrost it just going to make for being visibility issue plowing, were are you from pa ?


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## Randall Ave (Oct 29, 2014)

This started after you had the cab off? Put a pressure test on the system, if it doesn't drop, it ain't leaking.


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## rjigto4oje (Oct 27, 2010)

superdutypsd;2053419 said:


> I am going to try to clean the condensor before its to cold out, also was know sometimes you need to clean coils up in evap core, im gonn poke around thinweekend trying to figure it ouf as i want get this humid heat fined before snowfall because i know with moisture coming out defrost it just going to make for being visibility issue plowing, were are you from pa ?


Chicago....


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## Nero (Aug 10, 2009)

rjigto4oje;2053479 said:


> Chicago....


So have you unplug the AC pump? as I suggested earlier, easiest thing to do..

If that doesn't do it then bypass the heater core another easy thing to do 5 minutes tops. my question to you is have you done any of these things yet as we have suggested?

Do these very simple things first for the process of elimination. only takes seconds to unplug a compressor.

I think you're complicating things more than they are by cleaning the evaporator core.
as that may require dropping the dashboard.Then.... if my suggestions don't work then you may have to drop the dashboard and air box to get at evaporator core. and getting at the evaporator core will take some time.


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## superdutypsd (Oct 30, 2014)

Nero;2053512 said:


> So have you unplug the AC pump? as I suggested earlier, easiest thing to do..
> 
> If that doesn't do it then bypass the heater core another easy thing to do 5 minutes tops. my question to you is have you done any of these things yet as we have suggested?
> 
> ...


I will try both of these tomorrow, havent done anything as of yet, but can you exsplan a little more, unplugging the ac compressor, will do what possibly, stop the moisture in the heat, and the say bypassing heat core stop ac from disengaging


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## Nero (Aug 10, 2009)

superdutypsd;2053533 said:


> I will try both of these tomorrow, havent done anything as of yet, but can you exsplan a little more, unplugging the ac compressor, will do what possibly, stop the moisture in the heat, and the say bypassing heat core stop ac from disengaging


There are two ways of doing this. I will explain.

1. After you disconnect the two wires or plug from your compressor, run your engine & drive your truck around. lf you don't have any moisture now then it's your AC. and not your heater core.

If you still have moisture going on your windows it is a heater core leaking. Keeping in mind you may not always smell it.

2nd thing you can do to diagnose for a bad heater core do the following.

On your firewall on the passenger side you will have the inlet and outlet of your heater core.make sure they are hose clamps, that will tell you it's the heater core,and not the evaporator core. "do not pull off lines for the evaporator core" as the evaporator core will not have hose clamps they will have lock fitting and hard lines.

Loosen the two hose clamps from the two hoses that come from your heater core on your firewall, and get a piece of pipe and connect those hoses together, this will bypass your heater core.

Then drive vehicle around and see if you have moisture on your windows. if not? this means you have a leak in your heater core.

Personally I don't think it is your evaporator core. I have replaced more heater cores and evaporator condensers than I would ever want to, and some are a real bear.

And by the way, A ac 
evaporator core has nothing do with eliminating moisture from your heater.

As of now, don't worry about your AC engaging and disengaging.
First rectify this problem.


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## Whiffyspark (Dec 23, 2009)

If you do heater core replace evaporator core at the same time. Use ford parts


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## superdutypsd (Oct 30, 2014)

Nero;2053576 said:


> There are two ways of doing this. I will explain.
> 
> 1. After you disconnect the two wires or plug from your compressor, run your engine & drive your truck around. lf you don't have any moisture now then it's your AC. and not your heater core.
> 
> ...


Thank you see now im learning, i am will unplug ac and get back to you


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## superdutypsd (Oct 30, 2014)

Whiffyspark;2053592 said:


> If you do heater core replace evaporator core at the same time. Use ford parts


Yes i always use ford parts, have very good pricing on them with my dealer, i was thinking about replacing it all, evap, orface tube, condensor, and the the pump, and heat core if have to, everythings pretty cheap but a pump. Any reason you say to replCe those to together or just bc they are located together and come apart together


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## Whiffyspark (Dec 23, 2009)

Yeah they're in the same box. Murphy's law says if you replace one the other will screw up a week later lol


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## superdutypsd (Oct 30, 2014)

Whiffyspark;2053613 said:


> Yeah they're in the same box. Murphy's law says if you replace one the other will screw up a week later lol


:laughing: i know this all to well also


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## Nero (Aug 10, 2009)

Whiffyspark;2053592 said:


> If you do heater core replace evaporator core at the same time. Use ford parts


Words of wisdom I agree 100%


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## averhoog (Aug 5, 2015)

One thing to check with the ac cycling too much only when sitting make sure the engine fan is turning on to cool the refrigerant. When it doesn't engage the refrigerant overheats and will turn off also make sure that the recirculating door is working if not will be sucking wet air from the floor blowing it I the windshield


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## superdutypsd (Oct 30, 2014)

averhoog;2054266 said:


> One thing to check with the ac cycling too much only when sitting make sure the engine fan is turning on to cool the refrigerant. When it doesn't engage the refrigerant overheats and will turn off also make sure that the recirculating door is working if not will be sucking wet air from the floor blowing it I the windshield


How can i check to make sure my fan clutch is engaging, i tryed the old school way with a broom but couldnt tell, and do you know were the recirculating door is and how can i check


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## superdutypsd (Oct 30, 2014)

I tried unplugging me ac and still had same moisture problem, then when i by pass the heater core i lost all heat, im going to put a new heater core in hopefully tomarrow its 50 dollars and behind the glove box maybe a 30 min job here is a video for you if you ever have to replace your heater core pretty easy and straght forward


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## Nero (Aug 10, 2009)

superdutypsd;2054406 said:


> How can i check to make sure my fan clutch is engaging, i tryed the old school way with a broom but couldnt tell, and do you know were the recirculating door is and how can i check


I disagree, that is not a issue with this problem.


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## Nero (Aug 10, 2009)

superdutypsd;2054408 said:


> I tried unplugging me ac and still had same moisture problem, then when i by pass the heater core i lost all heat, im going to put a new heater core in hopefully tomarrow its 50 dollars and behind the glove box maybe a 30 min job here is a video for you if you ever have to replace your heater core pretty easy and straght forward


if you bypass the heater core like you did you would not get heat as you did not. but did you notice the windows getting full of moisture? You got lucky on that Ford it's one of the easiest heater cores to do.
On the older dodge Rams the book calls for roughly 6 hours for heater core and evaporator core. Believe me it's pretty accurate. Corvettes are the worst. I've done two of them regarding Corvette.


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## superdutypsd (Oct 30, 2014)

Nero;2054416 said:


> if you bypass the heater core like you did you would not get heat as you did not. but did you notice the windows getting full of moisture? You got lucky on that Ford it's one of the easiest heater cores to do.
> On the older dodge Rams the book calls for roughly 6 hours for heater core and evaporator core. Believe me it's pretty accurate. Corvettes are the worst. I've done two of them regarding Corvette.


I had to do my old jeep grand cherokee once a 8/9 years ago it was a 2001 and the whole damn dash had to come off


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## Nero (Aug 10, 2009)

superdutypsd;2054421 said:


> I had to do my old jeep grand cherokee once a 8/9 years ago it was a 2001 and the whole damn dash had to come off


I know, what a pain!


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## rjigto4oje (Oct 27, 2010)

I used to work for dodge and did at leat 3 a day. The one that really sucked is the mini vans. Wiper pod and mirrors had to be removed


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## superdutypsd (Oct 30, 2014)

Yea im glad ford did something with some sore of common sense on these trucks for once, and put it in a very easy place, i am going to replace the heater core and then take a shim off the compressor clutch to see if that helps, maybe the air gap has gotten to big


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## superdutypsd (Oct 30, 2014)

Do any of you guys know how i can test my fan clutch, i have a plow prep one that is ingaged more often and kicks in at alower temp, they are not cheap $380/400 so i would hate to throw a new one at it if not needed , also going to try and wash condensor


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## averhoog (Aug 5, 2015)

To test fan clutch when engine is cold should be able to spin easily when engine is hot should be locked up


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