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western relay problem

Discussion in 'Western Plows Discussion' started by shadowj38, Jan 10, 2015.

  1. shadowj38

    shadowj38 Junior Member
    from pa
    Messages: 13

    I have a 7' 6" unimount pro plow on my 09 silverado 2500. It is a 3 port 3 plug isolation module PN 29070-1 green label. My driver side low beam will glow but wont like. I have traced it back to the relay assembly PN 29859. So i call the western dealer and they tell me they have never heard of that part number. So i did some research and have found western replaced that part with a new one due to it being a fault. The new part is PN 28027-2. Has anyone else heard this? If so how does it work? Do you just unplug relay and plu new part in in its place?
     
  2. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    This two relay adapter kit goes on port number one on the three port module. What it does is prevent both the high beam and low beam filaments from burning at the same time. On the truck high and low are in two separate bulbs so they can both be on, and they are when in high beam mode. The plow, on the other hand, has high and low in one bulb. It's very simple to install, just unplug one side from the isolation module and the other end from the cable, then plug in the new one. The two plugs are different so you can't screw it up. But why replace the whole adapter? There are two relays with five pins on each, buy one relay for $12 and switch it in. If replacing the first one doesn't correct the problem then put the one you took out in the other spot. Chances are only one relay is bad. These relays are so commonly used, you could go to a junk yard and just take one out of an old car. Just look for one with all five pins, some have only four. I go to the dump regularly and fill my pockets with relays and fuses, they charge me $5 for a 20 liter jug of them.....

    Here is a link to the adapter and hookup: http://library.westernplows.com/pdfs/42003.00_031506.pdf
     
  3. shadowj38

    shadowj38 Junior Member
    from pa
    Messages: 13

    Ok. Do you know of a website i can order it from? And thank you for the help
     
  4. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    Just get on westernplows.com and look for the nearest dealer. At my shop in Calgary Alberta (Canada) we ship phone orders all over the country. Any dealer in your state will be happy to help you out, especially when you have the part number.
     
  5. shadowj38

    shadowj38 Junior Member
    from pa
    Messages: 13

    My truck is not already equipped with the 28027-2 harness. The harness that is plugged into the first port in the isolation module has a 6 wire plug that comes out of it with a relay (PN 29859) plugged into it. I was told western has had issues with this relay and they came out with harness PN 28027-2 to replace it. So after I put the harness into my isolation module, what do i do with the old relay? Do I just unplug it and let the plug hang there? Just to be sure you know what I'm talking about, if you look in westerns schematics guide, page 9 is the setup I have no. Page 8 I believe shows what i need. Thanks for the help. I'm just not sure if i put the new harness in ahead of the old one, how will my lights work without the old relay plugged in?
     
  6. shadowj38

    shadowj38 Junior Member
    from pa
    Messages: 13

    Also in my first post I said my plow was a unimount... It's an ultramount. Sorry.
     
  7. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    Uni or Ultra is irrelevant to this issue, you have a three port isolation module on a three plug (at the grill) system which can be used on either uni or ultra....

    If you plug in the relay harness without the relays installed your low beams will not turn off when your high come on, this will burn out your plow headlight bulbs prematurely.

    When you get the new 28027-2 you unplug the old adapter from the isolation module port one and from the headlight cable, there will also be a ground wire you need to cut or otherwise remove. Then you take the new one and plug one side into port one of the isolation module and the other plug into the headlight cable. Then reconnect the ground wire from the new adapter to the place where the old ground came off. The new adapter should come with two new relays. So.... there will be nothing left dangling, you should be able to just take the whole old unit out and discard it with the two relays. One of those two relays is bad, that's why your RH low beam plow light wasn't working properly. When you get the new one it will be obvious what to do.
     
  8. shadowj38

    shadowj38 Junior Member
    from pa
    Messages: 13

    There is no old harness to take out of the truck. It is a solid harness from the module plug to the plow plug. Except for the plug that is wired in to the harness. It is plugged into a relay PN 29859. Do I have to replace the entire harness?
     
  9. shadowj38

    shadowj38 Junior Member
    from pa
    Messages: 13

    I guess what I'm saying is the head light cable is plugged directly into the module. And it has a relay assembly PN 29859 wire directly into that cable. I understand I have to unplug the cable and put the 28027-2 adapter in the module and then plug the head light harness into the adapter. but what do i do with the relay that is wired into my current headlight cable?
     
  10. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    If that is the case you have been working with the wrong part number. You have the isolated adapter number but your truck has the integrated adapter. You have two options: Just replace the bad relay (cheap) or pull the whole cable from the iso module port 1 all the way to the grill and find the part number for the integrated cable / adapter. That will be lots more money.
    Another idea is to buy a generic 11 pin headlight cable without the adapter (26357) and then get the adapter you are talking about (28027-2) but again this will be a lot more $ than to just replace the bad relay in your existing integrated harness.
     
    Last edited: Jan 11, 2015
  11. shadowj38

    shadowj38 Junior Member
    from pa
    Messages: 13

    Ok that makes more sense to me. But the 2 places i have talked to (one being a western dealer) tell me the PN 29859 is non existant. But it's in my truck and in their wiring schematics. And I'm having a hard time finding it on the internet.
     
  12. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    Forget the 29859, as you said they had problems with that version. The new, reliable, version is 28027-2. It's pretty much the same thing just with different relays I expect. Higher current rating perhaps.
     
  13. cubicinches

    cubicinches PlowSite.com Addict
    Messages: 1,412

    29859 is a integrated relay assembly with a single six wire connector, and was an integrated part of a 29861 eleven pin lighting harness. The 29859 was prone to failures, and often times overheating and, sometimes, even a small fire under the hood when the relay assembly overheated and failed. Consequently, that relay assembly was discontinued, and as you've found, is no longer available. The 29859 relay cannot be directly replaced with single cube relays. As Mishnick said, the 28027 is to be used with a 26357 eleven pin lighting harness... In your case, you'd need to buy both. The updated eleven pin for your application is a 29861-3. It has two cube relays integrated into it, and does not require the use of a 28027 adapter. Soooo... a 29861-3 cable will directly replace what you've got, with no other parts required.
     
  14. shadowj38

    shadowj38 Junior Member
    from pa
    Messages: 13

    Thank you for the responses guys. That's what I was having trouble understanding. I did not think i could use the new adapter with my existing harness.
     
  15. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    Yes!!! That's the one you want, I concur with Cubicinches. This is the best and cheapest way to go. Once you have this integrated harness you will have the two "cube" 5 pin relays that can be replaced individually if they fail in the future. I knew these were available but have only ever seen them in headlight harness kits.
     
  16. shadowj38

    shadowj38 Junior Member
    from pa
    Messages: 13

    thank you very much for your help!!