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plow lights

Discussion in 'Sno-Way Discussion' started by DAYTONA Z, Nov 12, 2007.

  1. DAYTONA Z

    DAYTONA Z Member
    Messages: 53

    Back to working on the plow lights. If you followed this problem last year you'll remember how frustrating this is. On 99100197 harness on the plow light plug terminal #1 the black 12v wire, what does that go to on the light side plug.
     
  2. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,993

  3. DAYTONA Z

    DAYTONA Z Member
    Messages: 53

    At the plugs that connect the truck and the lights there is a black wire that is 12v hot all the time. It is terminal # 1 on the wiring diagram I got last year from Toby(I think it was). It was one from the factory showing all the details of the harness.
     
  4. hydro_37

    hydro_37 PlowSite Veteran
    from iowa
    Messages: 3,790

    I don't think there should be a black wire that is "hot" all the time with the lights off.
     
  5. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,993

    There is not suppose to be a constant "hot" in the system.
     
  6. DAYTONA Z

    DAYTONA Z Member
    Messages: 53

    Well now I am more confused because the truck lights work fine. This is the second wiring harness I have had. It is plugged ito the truck correctly. The truck lights work fine with the harness attached but if the plow lights are plugged in the relay trips but no power to plow lights.
     
  7. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,993

    When the relay trips do the truck lights go out?

    If yes then is there power going to the lights from the relay?

    If yes is there power at the grill plugs?

    If yes and you have nothing lit it might be grounds on the lights or every bulb in both lights is blown or bad plugs on both lights.

    what about TM and turn sig. do they work?

    Don't scoff the every bulb blown theory. One dude tracked a bad 12v solenoid then got 2 bad 12volts solenoid in a row last year all brand new from the dealer. It was a nightmare, solve the problem but still have it kept coming back to Occam's (?) razor
     
  8. DAYTONA Z

    DAYTONA Z Member
    Messages: 53

    1. Yes Relay trips truck lights go out.

    2. No. Other than the parking lights to trip the relay the only power are the wires with white stripes at the relay. (I am at work doing this from memory terminals 3&7 at the relay??)

    3. No power at plugs.

    4 I can power all the lights up with jumpers from the battery just fine. Turn signals and parking lights work fine on plow when relay trips.

    I have used 3 differnt relays. I have bench tested them and did find one bad one.

    I have used differnt grounds including directly to battery.
     
  9. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,993

    So you have power going in but not out of the relay. The truck works fine but the plow light don't come on. When you plug the plow lights in the relay trips and nothing happens. Try disconnecting the plow wires from the relay. see if when the relay trips the plow terminals power up.
     
  10. DAYTONA Z

    DAYTONA Z Member
    Messages: 53

    I'll try that tomorrow night. Can you confirm that would be terminals 2 & 6 / orange and black & red and black wires.

    Can we make sure I am analyzing this right. Terminals 4 & 8 are the power coming in from trucks harness to the relay. Then power is sent out through 3 & 7 or 2 & 6 depending on whether the plow lights are plugged in or not.

    Am I correct about this or am I out in left field??
     
  11. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,993

    Yes sir:waving:
     
  12. DAYTONA Z

    DAYTONA Z Member
    Messages: 53

    No power at 2 or 6.

    Plow lights unplugged, power at 4 & 3 or 8 & 7 depending on high or low beam as it should be.

    Plow lights plugged in power only at 3 & 7, the wires with white stripes.

    Back feeding???from where????
     
  13. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,993

    With the plow side wires off the relay? everything but the plow side connected.
     
  14. DAYTONA Z

    DAYTONA Z Member
    Messages: 53

    Correct wires on 2 & 6 pulled at relay.

    What is happening is when the relay trips the power stops coming in on the solid red and orange wires 4 & 8 and power is coming in only on the wires for 3 & 7.
     
  15. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,993

    Power should not be coming in the 3/7 they are power out to the truck.

    So when you plug the plow in the truck lights go out?
     
  16. DAYTONA Z

    DAYTONA Z Member
    Messages: 53

    correct plug the plow lights in and relay trips and the truck lights go out.

    Even stranger---- lights off on truck, truck off, power at 3 & 7 and 4 & 8.

    The truck lights work fine with or with out the plow harness installed.

    I was told or read this somewhere that Dodge vechicles run the light wiring ??let's call it backwards for lack of a better term, there is always power to the lights(like mine) and the circuity isn't completed until it gets back to the headlight switch.
    Isolated system with a hot ground?

    Does that make any sense or shed any light on my problem.
     
  17. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,993

    Sure it does, you have a "low-side switched system. Why you should be using the 197 or 529 harness. Your test light should be lit when the lights are out, go out when the lights come on. The system is controlled by the ground side. If you're not getting juice to the plow side of the relay when the circuit trips, it's operating correctly. I think you have a Plow light issue.

    Can you confirm all the grounds and current paths though the plow lights ?
     
  18. DAYTONA Z

    DAYTONA Z Member
    Messages: 53

    Using a 12v power source I can get the plow lights to work just fine.

    If I leave the plow lights unplugged and trip the relay with a jumper wire I get no power to the truck side plugs for the plow.
     
  19. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,993

    assuming you have it wired correctly you've either got a bad harness, and that's rare unless it's old inventory (snoway test all harnesses before packaging,) a bad relay, or the wrong harness/ adapter.
    I have no other advice to give except take it to a dealer.
    Keep us apprised
     
  20. DAYTONA Z

    DAYTONA Z Member
    Messages: 53

    2nd harness. I did have a bad one last year new from the dealer. Had a bad wire, no continuity using a multi meter. I will check this harness.
    I will bench test the relays again with the multi meter using a 12v power source to trip the relay. I will double check the adapter again vs the wiring diagram.