# Green label 29070-1 iso module, Ultramount, and 26421 config plug - Plow headlights not working



## Synchman (Sep 20, 2007)

I'm trying to help my brother Jim wire up his plow, purchased used off of a Chevy.

He has a 2002 Ram 2500, with a Western Ultramount, and a Green label 29070-1 3-port isolation module.

His plow controls and running lights work, but his plow headlights are not getting power. We checked the wires coming out of the "A" port of the isolation module, but only the running light wire has power. We also verified the plow presence circuit has a good path to ground, and the isolation module clicks when it is unplugged. Although it clicks for a while when the plow presence wire is disconnected.

With the plow plugged in at the front of the truck, the high beam indicator comes on even with the key out. It turns off with the headlight switch in the on position, or if the plow is unplugged.

Does he need the 26421 config plug or not? The Western wiring diagram PDF (p. 17) for 3-plug straight blade snowplows with central hydraulics say that "Configuration Plug is not required with 3-port light modules". The Western Quick Match site does not suggest this configuration plug either.


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## Western1 (Dec 4, 2008)

Did you purchase a new headlight harness for the Dodge? The headlights are different from the Chevy.


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## Synchman (Sep 20, 2007)

Excellent question, @Western1. The wrong harness would explain his symptoms.

You can see in the below photo a new harness.

He told me he purchased two new harnesses, but I don't know how he got the part numbers. He's off fishing right now, but I'll ask him to verify the part numbers on The Western Quick Match site when he gets back.


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## Synchman (Sep 20, 2007)

This is what I get in the Western Quick Match site:
2002, DODGE / RAM, RAM 2500 Chassis. 
The vehicle has a 4x4 drive train, Reg Cab body style, chassis cab, 8501 minimum GVWR, and HB1 headlamp type.

Headlamp Harness: 29050
3 Port Isolation Module: 29070-1

His invoice for the wiring harness shows the 29050 harness.


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## Western1 (Dec 4, 2008)

This is a little hard to explain but if you look at the headlight connectors on the plow harness there is two different ways to plug them in. That's because some trucks have a positive common. So take a look and let me know. That configuration plug is only for the 4 port applications.


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## Randall Ave (Oct 29, 2014)

I could be wrong, but his Dodge is positive ground on the headlights.


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## Synchman (Sep 20, 2007)

Western1 said:


> This is a little hard to explain but if you look at the headlight connectors on the plow harness there is two different ways to plug them in. That's because some trucks have a positive common. So take a look and let me know. That configuration plug is only for the 4 port applications.


Yes, he set up the headlight connectors for a positive common; negative switched ground.

Thanks on the detail that the configuration plug is only for the 4-port applications.


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## Synchman (Sep 20, 2007)

Randall Ave said:


> I could be wrong, but his Dodge is positive ground on the headlights.


Yes, 2002 Dodge has a positive common, switched ground.


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## Synchman (Sep 20, 2007)

Jim removed his plow and found that his headlights no longer worked. Checked the truck fuses and found the two headlight fuses are blown. There were some driving lights that had been cut off the truck, and could have shorted. We'll see if replacing the fuses and insulating the driving light wires solves the problem.


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## Western1 (Dec 4, 2008)

Ok let us know!


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## Synchman (Sep 20, 2007)

Western1 said:


> This is a little hard to explain but if you look at the headlight connectors on the plow harness there is two different ways to plug them in. That's because some trucks have a positive common. So take a look and let me know. That configuration plug is only for the 4 port applications.


To clarify what @Western1 is asking, I'm including a section of Western Plow Lit. no 29206, Rev 10:

"For vehicles using the 29050 Harness Kit
with HB-1 (9004) Headlamps: The 29050
harness comes from the factory configured for
HB-5 (9007) headlamps. To convert this harness
to be compatible with HB-1 (9004) headlamps,
first plug the vehicle headlamp connectors into the
plug-in harness with the locking tabs on the same
side as the "HB-1" text, and second, reverse the
position of the low beam and common wires in the
blue plug-in harness connector (move common
wire to pin A and low beam wire to pin B)."

So @Western1 wants us to be sure we put the locking tabs on the same side as the "HB-1" text, since we have HB-1 headlights, not "HB-5" which is stamped on the other side of the connector. Having this hooked up the wrong way could explain blown fuses and the high-beam indicator light on with the light switch off.


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## Synchman (Sep 20, 2007)

Jim replaced the headlight fuses, and when he plugged in the 11-pin plow lighting harness at the front of the truck, it blew both fuses again.

We have a test plan to activate the plow presence circuit and then jump each pin pair until we find the short circuits. I asked him to first confirm that the locking tabs are on the HB-1 side of the headlight connectors.

I did confirm in his photos that the headlight connector low and common are correct for his setup.

Any thoughts on what else could be wrong that would short both headlight fuses when the plow lighting harness is connected, although the headlight switch is off?


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## Randall Ave (Oct 29, 2014)

Power, or grounds reversed. Best thing to do is start over. Put the truck back to stock. Make sure everything works. Then do the plow harness connections again, following the instructions very carefully. So you are not physically there, your helping via photos?


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## Synchman (Sep 20, 2007)

Randall Ave said:


> Power, or grounds reversed. Best thing to do is start over. Put the truck back to stock. Make sure everything works. Then do the plow harness connections again, following the instructions very carefully. So you are not physically there, your helping via photos?


Correct, I'm not there.

Jim tested the light connector at the front of the truck, and found that pins #5 & 11 have power on the truck side, and go to ground on the plow side.

The plow is used. I suspect the plow headlights were re-wired. In the photo, looks like there is a wire coming out of the headlight and going to ground. That's not the stock configuration, per the wiring diagrams.





  








IMG_0267




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Synchman


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Aug 31, 2017




Rewired?


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## Randall Ave (Oct 29, 2014)

Well, you have to get a wiring diagram off the Western site, then pin it out and make repairs. Or replace the plowside harness. Are the headlights factory or aftermarket?


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## Western1 (Dec 4, 2008)

This should help


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## Western1 (Dec 4, 2008)




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## Synchman (Sep 20, 2007)

Thanks, @Western1. That is the correct wiring diagram for our setup. That shows there should be NO wires connected to the plow frame as ground. I think we have to correct the connections at the plow headlights to match this diagram.

I saw elsewhere on this forum that it not unusual for the plow headlights to be re-configured for a switched positive and common ground. I suspect that's what happened here.


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## Synchman (Sep 20, 2007)

Randall Ave said:


> Well, you have to get a wiring diagram off the Western site, then pin it out and make repairs. Or replace the plowside harness. Are the headlights factory or aftermarket?


Good question, @Randall Ave. They are aftermarket HID's. I've asked for pictures so we can sort out the make and the correct wiring for them.

Jim confirms there are ground wires coming from the plow HID headlights and going to the plow frame.


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## Randall Ave (Oct 29, 2014)

Ground wires going to the lift frame will not do much good as it kinda floats. Ya gotta do as stated, or your hunting for the albino buffalo.


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## Synchman (Sep 20, 2007)

We got it all working. Hooked it up per the wiring diagram above. We used a relay to switch the plow lights on, whenever the parking lights are turned on and plow is plugged in. Thanks for the help from this thread and from other forum posts.


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## Western1 (Dec 4, 2008)

Glad to hear you got everything figured out!!! Good luck!


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