# 99 f350 question



## Frycztech (Dec 27, 2012)

I have a 99 F350 with a Fisher MM2 when I raise the plow the lights dim bad and the heater slows down. What is the best way to fix the problem? I threw a Redtop in from another car i had in and it didn't help. Any suggestions?


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## FordFisherman (Dec 5, 2007)

Start with removing and cleaning ALL your electrical connections for plow and n
battery.


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## Frycztech (Dec 27, 2012)

ok I cleaned all the terminals and that didn't help. Someone said that I should upgrade the ground and power wire to the alternator, should I do that?


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## Plowtoy (Dec 15, 2001)

Frycztech;1549605 said:


> ok I cleaned all the terminals and that didn't help. Someone said that I should upgrade the ground and power wire to the alternator, should I do that?


That wouldn't hurt. Is it a 7.3? My buddy last winter went through 6 alternators before putting on a new hot to the battery and ground. You need to make sure you have a fuse or fusible link in the hot if you do that. Good luck


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## Frycztech (Dec 27, 2012)

No its the 5.4L


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## Plowtoy (Dec 15, 2001)

I'm not sure if it was as big of an issue on the gassers, but it's not going to hurt anything to put the extra cables on. Again, just be sure to add an in-line fuse or fusible link to the wire from the output on the alternator. You might just take the alternator out and have it tested. It may just be weak and not able to keep up. Its a pretty easy job on those engines.


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## Milwaukee (Dec 28, 2007)

You can do that on 5.4L the cable to alternator are too small and it turn red to yellow/white.

Do what Plowtoy say. I told him last year to add cables. I would get thicker cable like welder cable size should be plenty for volt go though cable and not heat up cable like factory cable was.


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## tjctransport (Nov 22, 2008)

put a second battery in and upgrade your alternator. with only one battery and a 85 amp alternator you are overpowering it.


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## MickiRig1 (Dec 5, 2003)

Your going to have a dimming of lights and slow down of the blower. The pump pulls major amps which drops the voltage. Use the search function on the gray line above. Search: low power, lights dim, duel batteries, high output alternator, ect. You will finds hours of reading. It's a subject beat to death since plows were bolted on trucks.


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## bpminc74 (Jan 15, 2012)

I am having the same issues with my 7.3. Upgraded to a 200 amp alt. and same thing. At idle I am getting 11.8 v at alt. At high idle it's reading 14.3. Checked to see if glow plugs were staying on or the fuel heater and both checked out o.k. Seems like there is a draw somwhere. Gonna upgrade charging wires today to see if it makes a difference. My only question is can I leave the existing charging wire hooked up with the upgraded cale or should it be removed?


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## dieselss (Jan 3, 2008)

bpminc74;1551732 said:


> I am having the same issues with my 7.3. Upgraded to a 200 amp alt. and same thing. At idle I am getting 11.8 v at alt. At high idle it's reading 14.3. Checked to see if glow plugs were staying on or the fuel heater and both checked out o.k. Seems like there is a draw somwhere. Gonna upgrade charging wires today to see if it makes a difference. My only question is can I leave the existing charging wire hooked up with the upgraded cale or should it be removed?


where are you cking for the 11.8??? and i left my factory alt wire, and ran a new 2g wire right to the drivers side batt,,thats where i have all my plow stuff hooked to and no issues


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## bpminc74 (Jan 15, 2012)

I get 11.8 at the battery with truck running. With truck off I get 12.9 at battery.


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## dieselss (Jan 3, 2008)

bpminc74;1551760 said:


> I get 11.8 at the battery with truck running. With truck off I get 12.9 at battery.


what batt???


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## bpminc74 (Jan 15, 2012)

Driver side. I disconnected the cables when I checked battery volts. Both batteries are 12.9 volts. Just installed heavier charging wire and checked again with sct programmer and voltmeter with truck idling still 11.8 v.


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## dieselss (Jan 3, 2008)

But your only getting that at 1 batt? What's the other batt getting and what's the grounds looking like?


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## bpminc74 (Jan 15, 2012)

Getting that at both batts. Grounds are good and clean. Thinking I need a smaller pully on this new alt. At1000 rpm its putting out 14. 4 v.


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## dieselss (Jan 3, 2008)

No. Is it the same size as the factory one?


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## bpminc74 (Jan 15, 2012)

yeah, its the same size.


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## dieselss (Jan 3, 2008)

Then maybe. Is the new alt rated at idle range or above? Sounds like its rated for driving rather then idling


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## bpminc74 (Jan 15, 2012)

Got fed up and put the original 110 amp alt. back on and now i'm getting 14.3 v at idle. I guess the 200 amp alt. is faulty. The reason I swapped the original uot for a higher amp is because I had significant voltage drop when plowing. The 200 amp is worse than the 110. Will call DB tomorrow to see whats up with the 200 amp.


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## MickiRig1 (Dec 5, 2003)

The alternator should be putting out 14.5 when running. Most time batteries in good shape are 12.6 or better static. ( engine off ). An alternator puts out 1/3 it's rated amps at idle. Full at 2,000 RPM or higher. Upgrade the wire size to the batteries. Check all your grounds, clean and protect with Dielectric grease. I think your alternator was bad right out of the box. Counter guy told me 1 in 10,000 parts are bad right out of the box. So why am I, always Mr. 10,000?


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## BigLou80 (Feb 25, 2008)

Lots of high amperage alternators put out lower voltages, its all watts and amp= volts/watts

Having had a similar problem along with many many more in my 99 F350 I can tell you with certainty the best thing to do is replace the POS with a GM and it's problem solved. Redoing the charge wire and adding a second battery will help you issue, but the underlying issue of the truck is a turd from a company that can't even get a charge wire right will still remain.


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## dieselss (Jan 3, 2008)

Easy killer,,,,,every tk has there problem. Keep us posted on what db says


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## TJS (Oct 22, 2003)

I put dual batteries in my 02 SD 5.4. I checked my set up today with a meter. Found that the aux battery was not at 14.5 volts when running it was 12.62 volts. This was after reading this post and I decided to run a dedicated ground from the alternator mounting lug and a dedicated power wire to the main battery. I thought I was all set till I put my meter on the second battery. I am using 1/0 welding cable for the second battery. The ground for this runs from the battery to the where the air filter bracket bolts to the support. Guess what this is a crappy ground. I ran a jumper cable to a spot on the frame to the aux battery negative lug and wala, got 14.5 volts. I am going to re-do my ground for this as well as run a larger ground for the main battery. Sorry for the highjack but grounds are very important.


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## Frycztech (Dec 27, 2012)

Dose anyone know where I can get a second battery for my 99 f350 I looked everywhere for the wrangler one and couldn't find it anywhere. I have a spare battery and can make cables but i need to mount it somewhere.


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## mwalsh9152 (Dec 30, 2008)

find a diesel truck aux battery setup. You might be able to find one in the junkyard. Might even be able to get the cables from it too


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## TJS (Oct 22, 2003)

Frycztech;1555042 said:


> Dose anyone know where I can get a second battery for my 99 f350 I looked everywhere for the wrangler one and couldn't find it anywhere. I have a spare battery and can make cables but i need to mount it somewhere.


Take the dual battery link in my signature, That should give you some ideas.
T.J.


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## Frycztech (Dec 27, 2012)

TJS;1555425 said:


> Take the dual battery link in my signature, That should give you some ideas.
> T.J.


What mount did you start with? Do u have any part number?


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## TJS (Oct 22, 2003)

Frycztech;1555447 said:


> What mount did you start with? Do u have any part number?


Look up Auxiliary battery for a Diesel set up. All you need is the tray. I also bought the support for it thinking I needed it. 
Thanks.
T.J.


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