# 08 Fisher V plow dim lights



## bergeros (Dec 6, 2009)

Hi all, 08 3500 GMC dually, hooked to it's new 8'6" V plow. Plugged everything in and the low beams are very dim, like daytime running light dim, but it's all plug and play. High beams are great and bright. Any thoughts? Thanks


----------



## SnowplowingLady (Nov 23, 2009)

*Check for a bad ground or other connections*



bergeros;890982 said:


> Hi all, 08 3500 GMC dually, hooked to it's new 8'6" V plow. Plugged everything in and the low beams are very dim, like daytime running light dim, but it's all plug and play. High beams are great and bright. Any thoughts? Thanks


I will check all connections for low beam. Some time a bad connection not letting enought power thur. So far I been finding a bad ground. Due to poeple thinks metal to metal is a good ground. Not all the time. 
May need to run a ground wire from the ground on the battery. For a good ground. Just repeating what the repair shop told me.


----------



## BSM Exhaust (Dec 5, 2009)

Check the plow electrical connection plugs and make sure thet are clean not corroded and the prongs inside are not bent or broken in anyway. Its good to use dielectric grease in the connectors too!


----------



## BSM Exhaust (Dec 5, 2009)

Also check the headlight wires and the bulb holders. Look for broken or chaffed wires and also corrosion due to moisture in the headlight bucket.


----------



## bergeros (Dec 6, 2009)

*one more thing...*

first thanks for the replies, I'll add one more thing. The plow and truck are both brand new, and the use of the Fisher isolation module and plug and play technology is in use. Both the low beams are affected. I just checked with a meter and found 12.48 volts on the high and low beam wire. When I assembled everything I did use the dielectric grease, big fan. I was wondering if anyone knew a problem from Fisher or a known ground issue on the 08 GM vehicles.

Thanks again... will await your posts.ussmileyflag


----------



## JayJay (Jan 23, 2009)

I am having the same problem.What color label is your isolation module it could be the wrong iso mod


----------



## B&B (Nov 4, 2006)

You have one or more of the headlamp connectors plugged in reversed. If you note on the connectors there's an "A" and a "B" side and they can be connected either way, but only one way is correct for the lights to function.


----------



## bergeros (Dec 6, 2009)

*B&b*

I plugged the A to the A and the B to the B.... should I try reversing them thinking Fisher made the wrong connection/labeling?

Jay Jay, I'll have to take a look at the iso module. I will get back to you tomorrow. Sorry your having the same problem....however misery loves company.


----------



## BSM Exhaust (Dec 5, 2009)

Can you bring it back to the dealer who installed it?


----------



## bergeros (Dec 6, 2009)

*Bsm*

I can bring it back to the dealer I bought it from... I installed it. I am VERY handy and can do anything when it comes to mechanical electrical etc. I just find it odd that I follow...yes even read the instructions to a "T" and have this issue. I think it is a Fisher issue...so yes I need to contact the dealer. I thought in the meantime I would see if anyone had the issue in the past and found a resolution.... maybe I had a "blond" moment. :laughing:

So, once I figure it out, I will post, so the next poor sap that does all the work themselves as I have, will atleast know hoe to fix their or Fisher's wrong. wesport

Thoughts?


----------



## JayJay (Jan 23, 2009)

Call dealer today and they told me to swap the to positive wires(low & hi beam wires) in plow headlamps. I did the to my and it worked just fine. Do you have a 3 or 4 port iso mod? Did your wire kit come with the 2 relay pigtail? If not i can get you the part # . Hope this was some help I plowed all last season with dim low beams or with the hi beams on.


----------



## bergeros (Dec 6, 2009)

Jay Jay, I have a three port Iso mod green label. When I tested in the headlamps I found power on the common and found that odd. Do you recall if you cut the low and common wire and reconnected? I called my dealer and they just said to try replugging into the iso mod, but that did nothing for me. Thanks for the info, let me know what wires you moved if you can.

Thanks!!


----------



## RepoMan207 (Oct 7, 2008)

bergeros;894090 said:


> I plugged the A to the A and the B to the B.... should I try reversing them thinking Fisher made the wrong connection/labeling?
> 
> Jay Jay, I'll have to take a look at the iso module. I will get back to you tomorrow. Sorry your having the same problem....however misery loves company.


That's what B&B was telling you, you need to reverse them, keeping them the same from passanger side to drivers side.


----------



## bergeros (Dec 6, 2009)

I have a three port iso mod. I tried switching the wires around A B C, but that did not work. I did find the B is the right side and the C is the left side of the lights, and A handles the disconnect etc. Jay Jaay correct me if I am wrong, but I understand your post to be the following. Cut the wires in the headlight itself for the high and low and reconnect them. Correct? Talked to the dealer....not much help...they are backed up for 3 weeks and can not squeeze me in. Urgh!!


----------



## RepoMan207 (Oct 7, 2008)

What "C", There is no "C".?.?.?


----------



## JayJay (Jan 23, 2009)

First Don't Cut any wires. Do you have the in line adapter kit part # 28027-2? It should be plugged in ios port A it has 2 automotive type relays. If you do try removing the 2 wires from the socket that is plugged into the plow lights w/ a small screwdriver and switch them. Hope this helps JJ


----------



## RepoMan207 (Oct 7, 2008)

JayJay;899012 said:


> First Don't Cut any wires.


----------



## bergeros (Dec 6, 2009)

*Got it!!!*

First, I want to thank everyone for the posts.... way more helpful than the dealer.

Second, the issue with the dim lights on low was the common or ground wire. When connecting the Fisher wiring to the GM wiring, at the headlights, there is two ways it can be connected. I had to unplug and turn the plug around 180 degrees to reconnect. My common or ground was not lined up with the GM ground. I had the dumb luck of doing it to both sides.... so be aware there is no slotted connector for only one way to plug things in.

I am only posting this so the next lucky guy or gal that decides to install there own plow and find the same fun I had or Jay Jay, will know now how to fix it.

Happy Plowing!!!wesport


----------



## 2COR517 (Oct 23, 2008)

Thanks for posting how you fixed it. Things were getting ugly fast LOL


----------



## B&B (Nov 4, 2006)

2COR517;919900 said:


> Things were getting ugly fast LOL


Despite the fact the the solution was provided in post #7.

Good to hear you're up and running. :salute:


----------



## 2COR517 (Oct 23, 2008)

yup................


----------



## bergeros (Dec 6, 2009)

Yup B&B rocks.... just didn't follow exactly what he was saying... my brother made those connections... so it was foreign to me. LOL

Anyway... alls well, no wires were cut, and I still have my dignity...:laughing:


----------



## B&B (Nov 4, 2006)

bergeros;920971 said:


> Yup B&B rocks.... just didn't follow exactly what he was saying... _my brother made those connections_... so it was foreign to me. LOL
> 
> Anyway... alls well, no wires were cut, and I still have my dignity...:laughing:


Blame it on the bro then.


----------



## farmboy52787 (Mar 22, 2007)

*I am having trouble with this as well*



bergeros;919699 said:


> First, I want to thank everyone for the posts.... way more helpful than the dealer.
> 
> Second, the issue with the dim lights on low was the common or ground wire. When connecting the Fisher wiring to the GM wiring, at the headlights, there is two ways it can be connected. I had to unplug and turn the plug around 180 degrees to reconnect. My common or ground was not lined up with the GM ground. I had the dumb luck of doing it to both sides.... so be aware there is no slotted connector for only one way to plug things in.
> 
> ...


So I am in your same exact situation, I have a 2011 GMC 3500HD Diesel regular cab work truck with a Fisher Xtreme V. Now we tried switching these plugs and then the lights dont work? Is it something in my truck harness then? I have talked to 2 fisher dealers and they say something is corroded and its not getting full power. Also if you unplug a relay that comes off connection A then the headlight that is plugged in will have full power and not be dim. Any help will be appreciated. Thanks


----------



## RepoMan207 (Oct 7, 2008)

farmboy52787;1560106 said:


> So I am in your same exact situation, I have a 2011 GMC 3500HD Diesel regular cab work truck with a Fisher Xtreme V. Now we tried switching these plugs and then the lights dont work? Is it something in my truck harness then? I have talked to 2 fisher dealers and they say something is corroded and its not getting full power. Also if you unplug a relay that comes off connection A then the headlight that is plugged in will have full power and not be dim. Any help will be appreciated. Thanks


New install or existing?


----------



## farmboy52787 (Mar 22, 2007)

New Install, well we installed it right before last winter, we didnt have many storms during nighttime last year so we didnt really notice it. We thought it was the plow headlights so we replaced them, but after trying a different plow on the truck we had no luck. So its been like this since we've had it and we installed it ourselves. We also have a 2012 GMC SLE same plow and harnesses and that trucks low beams work fine.


----------



## RepoMan207 (Oct 7, 2008)

Did you buy the truck's wiring new, or was it used?


----------



## farmboy52787 (Mar 22, 2007)

It came new from the dealer


----------



## RepoMan207 (Oct 7, 2008)

And they're calling it a corrosion issue....that's too funny. It's a configuration issue, when you say you reversed the connectors, did you do so at the lights, or the vehicle harness? Look at the top of the connectors, swap all of them to either A or B, don't mix and match as this will further confuse the situation.


----------



## farmboy52787 (Mar 22, 2007)

We turned the connectors from the vehicle lighting that plugs into the fisher harness, 180 degrees, and that caused us to have no lights at all for the low beams


----------



## RepoMan207 (Oct 7, 2008)

Go around and swap all 4 to A or B (head lights and harness), just double check them, those suckers are hard to read in certain lighting. Make sure there isn't a configuration plug in the configuration port up by the ISO as well. Unplug the harnesses going into the ISO, and affirm that they're in the right sockets (see below), and when you re insert them, make sure you hear that audible "click" indicating they're fully seated. If that doesn't work, go back around and re flip the connectors to their opposite sides.

Disregard the notations...something previous.


----------



## farmboy52787 (Mar 22, 2007)

Ok so just for the low beams or high beam connectors too?


----------



## RepoMan207 (Oct 7, 2008)

All of them.


----------

