Headlamp Relay Harness Issue

[Lycaon]

I installed my new E code glass ZJ headlamps with the Painless Wiring relay conversion harness over the weekend. What it does is plugs into one of the stock headlamp connectors and uses the terminal voltage at the connector to actuate the relays in the new harness. The new headlamps are then directly power sourced from the battery through the toggling of those relay switches.

The problem I'm having is that according to the Painless Wiring tech department (who could not provide me with any tech info on the problem ) the relay harness was designed for older vehicles that did not use a body control module to control the headlamps; basically it's designed for on/off low, on/off high and that's it. The ZJ uses a BCM to control the different combinations between low beam, high beam, and fog lamps.

What seems to be happening is that the relay harness is confusing the BCM and it thinks the high beam circuit is active 100% of the time regardless of low beam/high beam actually being switched on. This causes the high beam indicator to be illuminated on the dash, and it automatically kicks out my fog lamp circuit if the headlights are switched on (parking lamps only still allows use of the fog lamp circuit) and half the time it wont switch off of low beam. I haven't figured out a pattern to that yet, seems to be random.

Does anyone have any idea how to clear up this issue? I can't seem to find any info about this happening in any of the write-ups for this conversion.

[Ruepart Hoaxley]

Need a resistor in it somewhere. Or just live with it and wire the fogs to a switch.

[Lycaon]

so im thinking the issue may be elsewhere now, just coincidentally faulting at the same time i installed the lights. which would make sense because the relay harness should not cause any electrical confusion whatsoever. possible the multifunction switch itself is at fault? i unplugged the relay harness and plugged the adapter heading off the stock headlamp connector directly into the headlight and it has the same effect on the system.

[Ruepart Hoaxley]

Take the switch module apart and clean the contacts and stuff it with dielectric grease

[Lycaon]

the headlamp switch or the multi-function?

[Ruepart Hoaxley]

The module in the dash. Pull it apart and take some 4-ought steel wool to the contacts.

[Lycaon]

So pulled the multifunction switch apart last night, cleaned and re-greased all the terminals... no results.

Jumped the terminals in the connector, still has the same problem.

Moving down the line I'm thinking the next fault may be in the BCM itself, im going to test around jumping some of the other connectors and see where I can pinpoint things.

[Lycaon]

Had the BCM scanned; no definitive results. Tech said there were codes for open relays; this may have been from unplugging during testing as the parking lamps and automatic headlamps all function as they should.

Tried swapping out to a different BCM; no results.

Inserting the connector at an angle and cutting the input from the high beam circuit into the headlamp allows the lamps to function correctly.



edit: I'd also like to add that the 'flash to pass' feature works only when the parking lamps are set on, 'flash to pass' will not work when the headlamps are switched on.

[Lycaon]

found the issue, high pass relay in the engine compartment was grounding out the low beams to the flash to pass circuit. took it out and shook the death out of it, popped it back in and now everything functions normally, except of course there's no high beams because the relay is bad, but the circuit is functioning normally, high pass and high beams on triggers the low beams and fog lamps off.

[Lycaon]

scratch that. moving the relays around broke the ground on a broken wire i didnt see, now ill have to rewire the relay harness... i guess painless wiring is pretty painful after all

[Lycaon]

finally...

reattached the lead that broke free of the connector on the relay harness. did some research on the harness adapter and found that the pin locations, although the same connector, between the 9004 and 9007 are all different.

what was happening was the low beam circuit was active; as low/ground works reversed, but the high beam circuit was backfeeding through the low beam pin as a ground. pulled the pins out of the adapter and swapped them to the 9004 configuration, and finally after a week of frying my brain over wiring harness diagrams my lights are working again.

/thread