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only one headlight on plow (low beam)

Discussion in 'Western Plows Discussion' started by GripTruk, Dec 19, 2009.

  1. GripTruk

    GripTruk Senior Member
    Messages: 374

    One low beam only will work on the plow, both low beams on the truck work when the plow is unhooked, both high beams work on both the plow and truck.

    If I switch plug 3 and 4 then the opposite low beam will work so it's not a bulb or the plow connection, I think it's something in the isolation module or something.

    Ultramount
    4port, 3 wire module.
    2009 Chevy silverado 2500 HD

    I tried that configuration plug thing in both configurations, one way the one worked, and the other way neither worked. I think I have it negative common.

    any ideas?

    Thanks.... Jer
     
  2. twinman326

    twinman326 PlowSite.com Addict
    Messages: 1,683

    I believe your vehicle is positive common.

    Hard to tell from what your saying. If port 3 (driver side head lights) ) harness is not working, and you plug it into port 4, and it does work, the I would say there is something wrong with the mod. Before you make the decision to replace the mod, check the harness that giving you trouble. You might have bent pin...

    Or it can be a configuration...

    There is a warning

    lightA.jpg

    configuration for the lights

    light.jpg

    lightA.jpg

    light.jpg
     
    Last edited: Dec 19, 2009
  3. GripTruk

    GripTruk Senior Member
    Messages: 374

    Thanks for the reply, Twin, I appreciate the help!

    OK, I had a feeling it wasn't too clear what I said, and it's funny, you phrased the same thing I said in a different way and that made me think of it in a different way, so even that helps.

    I tested the low beam (Vehicle) lights and only one worked initially. I found a post on here that said to reverse the polarity on the plug that goes from the harness to the vehicle light adapter on the light that wasn't working, and that worked. after that the low beams on the truck both work when the plow is unplugged.

    I have tried the configuration plug in both positive and negative, and negative works (for the vehicle lights) while I think neither low beam worked in positive.

    As far as the light harnesses, I know the plow connection is good because both lights CAN work.

    Essentially, if I plug passenger side into 3 and driver into 4 then driver works, if I switch driver to 3 and pass to 4 then Passenger works.

    I didn't think of it as far as the iso mod itself being bad, more that I had something wired wrong, but I guess it's certainly a possibility.

    I don't what else I should check, or if there is a way to test the iso module to see if it's bad, beyond swapping it out for a different unit, which I'd do if I could.

    any help would be great.... it's snowing!

    -Jer
     
  4. RepoMan207

    RepoMan207 PlowSite Fanatic
    from Maine
    Messages: 5,031

    Ahhh, I could be wrong here, but I thought you weren't suppose to use a 4 port on 08 & 09 GM...

    & on the GM's you reverse the common at the headlamp harness, not by the configuration plug. The plug in is reversible where the vehicle harness and the ISO headlamp harness meet. There marked "A" & "B", just simply reverse them.

    Where did you get the 4 Port & how did you go about figuring that was what you needed?
     
  5. Philbilly2

    Philbilly2 2000 Club Member
    Messages: 2,552

    Had this happen on a truck that I did an install on. There is one connector that he had to fip. When he got home and hooked to his plow, he had both high beams and only the passenger side low beam.

    I know it was only 1 plug that had to be flipped or plugged in different and they worked. I will find out and report back.
     
  6. GripTruk

    GripTruk Senior Member
    Messages: 374

    Thanks guys!

    Repo-

    I had this plow setup on my old truck and simply got the frame mount and headlight adapters for my new truck. I had a 4 port and I am using the same unit. It worked fine before but as of yet I don't have a way to test it to be certain. I have not heard that I needed a 3 port for this truck but that would certainly be a bummer since everything but one function is working.

    As far as the common reversing, like I said above, i DID have to reverse one of the leads on the truck because the one vehicle light wasn't working. (driver) I have to imagine that if I go and switch it on the passenger side then that one would STOP working, since it is currently working with the plow disconnected.

    I did see somewhere that the configuration plug should possible be replaced by a cap, ie, removed entirely, but I think I tried that in my troubleshooting, I'll try again though to make sure.

    Philbilly-

    it sounds like what you're saying is exactly what is wrong with my setup, if his truck lights worked right but the plow lights didn't.

    I'm looking forward to an update from you on that.


    -Jer
     
  7. twinman326

    twinman326 PlowSite.com Addict
    Messages: 1,683

    That is weird.......Reading what I posted "If the LEFT (driver side) does not illuminate change the "plug" (not plugs) configuration to positive common. So if the driver side was not or illuminating, that plug should of been switch B to C, instead of B to A??

    As for what Repo statement, when I did a quick match on western using your truck info, it did come up with a 3port

    Truck info
    chevinf.jpg


    Iguess anything is possible.........Maybe he can use a 4port. U do have DRL??

    chevinf.jpg
     
  8. RepoMan207

    RepoMan207 PlowSite Fanatic
    from Maine
    Messages: 5,031

    Just because it worked fine before, does not mean it's going to work fine on your new truck. What was your old truck? Again, I am fairly certain you can't use a 4 port on these trucks.

    Sorry, I saw you swapped ports, but not the plug ins. I re read and saw it now.

    Remove the configuration plug all together. It does not belong there at all.

    Come to think of it, your not suppose to have to flip the 4 port ISO connections as it is separated within the module.

    I'm going to go ahead an sit back an watch on this one, but I guarantee you have the wrong ISO module.
     
  9. RepoMan207

    RepoMan207 PlowSite Fanatic
    from Maine
    Messages: 5,031

    I tried finding a B&B post, I'm almost positive Mike corrected someone on this before, but I couldn't locate the thread I was thinking about to confirm.
     
  10. GripTruk

    GripTruk Senior Member
    Messages: 374

    Thanks again. I'm really hoping you're wrong, REPO, as I imagine that needing the 3 port will mean I wasted a lot of time on this 4 port, and I agree that the fact that it worked before is no proof that it should work now, that's why i'd love to be able to test it. I guess I wonder how the 4 port iso module would know what kind of truck it's on and why it would make a difference is that a DRL issue?

    I'm actually not too sure about the function of DRLs on this truck, if it has them at all, I never thought too much about it before now. They are not required here and I have no desire to have them on the plow so if that's the only thing that doesn't work I'm fine with it, if one low beam doesn't work, that's no good, of course.

    -Jer

    PS, as far as the 3 port, how does that work? right now i have the control harness, the plow light harness and 2 truck light harnesses, do the truck light harnesses get combined on the 3 port? what would I need to replace to swap over?
     
    Last edited: Dec 20, 2009
  11. cubicinches

    cubicinches PlowSite.com Addict
    Messages: 1,412

    That system will work with a 3 port or 4 port module as long as you have the correct harnesses for each. What did the 4 port system you're using come off from? What color is the label on the 4 port module?
     
  12. RepoMan207

    RepoMan207 PlowSite Fanatic
    from Maine
    Messages: 5,031

    I doubled checked Western's site...White Label 26400 is listed. Is that what you have?

    Just to clarify, It's not a matter of not working, it's a matter of it working on your particular truck. You can take one of a GM and put it in another GM...doesn't mean it will work unfortunately. We couldn't confirm that off Fisher's site if we tried, as your particular truck doesn't list a 4 port to compare it to. SEE ABOVE, double checked Western's site to be sure....

    Your truck does have DRL's, as ALL late model vehicles have them now. That wouldn't play a roll in your one headlight though. Either the DRL's will work when your plow is hooked up or it won't I believe, that is another issue all together, one that probably won't be an issue anyway.
     
    Last edited: Dec 20, 2009
  13. twinman326

    twinman326 PlowSite.com Addict
    Messages: 1,683

    Last edited: Dec 20, 2009
  14. twinman326

    twinman326 PlowSite.com Addict
    Messages: 1,683

    Let us know what happen
     
  15. twinman326

    twinman326 PlowSite.com Addict
    Messages: 1,683

    Last edited: Dec 20, 2009
  16. GripTruk

    GripTruk Senior Member
    Messages: 374

    Duh alert!!

    OK, so i went back to the truck to look at things and try some of the stuff discussed here.

    I messed around with the configuration plug again, which would turn the lights off completely if removed. I had to pull the plow off and when I disconnected it, to my surprise, one of the lights on the truck that was "definitely working" was not on!
    I could SWEAR they were both working before I connected the plow, swear to god!

    Nonetheless, one wasn't working, so I tried to switch that "A" plug around to reverse its polarity and it worked, the vehicle light (low beam) came on!

    Now the big test, to see if this would carry over to the plow lights, I hooked it back up and.. Voila, 2 low beams!

    I don't know if I was tired or I missed something or I was dreaming, but I could swear both lights on the truck had been working, but they weren't, and I guess that was the problem.

    I appreciate all the help, and even though it was just a silly oversight, I think I learned a lot from this thread and I'm sure it will help people in the future with similar problems, or questions. For instance, a 4 port isolation module WILL WORK on an 09 chevy!

    Thanks so much again for all your help guys, and I look forward to more help on my upcoming "Why the hell does my plow sit so low?" thread

    -Jer
     
  17. twinman326

    twinman326 PlowSite.com Addict
    Messages: 1,683

    GripTruk

    Glad to be a service.....You have a happy holiday, and good luck.........

    Make sure you download those PDF's and keep them. Next time you might need them..
     
    Last edited: Dec 21, 2009
  18. GripTruk

    GripTruk Senior Member
    Messages: 374

    Well, after a MONTH at the body shop, after my friend borrowed my truck and got hit by a semi, I just got my truck back. The front left headlamp was replaced and they replaced part of the western light harness as well, as the adapters were damaged.

    Now, once again, I only have one low beam on the plow. I just spent a half hour switching those two plugs (which is a big pain in the ass, BTW) back and forth every which way I could think of. The truck only gets both low beams in one configuration, and the plow never got both. In at least one configuration the HIGH beams were dimly lit but the low beam (on the truck) was not. I really don't know what they did different, but I'm sort of back to square one here. I swapped the headlight plugs at the ISO module to confirm that the left and right plow lights both function.

    Also, when I connect it so both low beams work on the truck, both high beams on the truck work, or on the plow if it is connected.

    As if it wasn't bad enough that I've been without my truck for a month and missed 2 major storms, now I have to deal with this again.

    Ideas?

    -Jer
     
  19. twinman326

    twinman326 PlowSite.com Addict
    Messages: 1,683

    Look at what you wrote in you last post (#16), you had them working..........Maybe when the body shop replace the harness, they didn't reverse the pins????
     
  20. GripTruk

    GripTruk Senior Member
    Messages: 374


    Yeah, that's what I figured, like I said, I tried switching the pins on both low beams every which way I could think of and came up with many variations of not working.

    The truck is back in the body shop till probably tuesday or so, so I can't do much until then, but if anyone else has an idea, especially based on the the high beams lighting up dimly (on the truck) i'd love to hear it.

    -Jer