H3 Headlight issue

[Hunner]

My drivers side headlight was out last night. I took it out unplugged and re-plugged and and it came on but very dim. Ok bought some of the new Ultra Star to replace the Silver Star in there. Same thing, very dim.
I have checked for damaged wires but will have to get in the warm shop to go further.
Pass side is bright.

Anybody got ideas??

 

[Ghostbuster]

Try to clean the contacts in the plug. Maybe put some dielectric grease on them.

That is odd that it is working... but dim. Good luck Hunner.


Sent from my iPhone using Tapatalk

 

[Hunner]

I stuffed some emery cloth in there a few times, on the old one but this one is new. I used dielectric grease which DOES NOT conduct electricity but will keep moisture out. I guess I should get a relay and see it that does it. Could be one side is fried.

 

[rascole]

Have you tried the brights to see if they are dimm too? If it's only 1 light there may be a bad connection where the T is behind the radiator support.

 

[Hunner]

New relay did not help. When I go to bright the pass side gets bright but the driver stays dim! I think it may be a ground but all that is in wire loom and I am not sure there are any connections until it gets up by the firewall and that big ground connection is there. Tried pulling that and using contact cleaner.
Thanks for the replies, maybe someone has had the same thing.
I checked other forums and there are several mentions of it but not any specific answers.
Im wondering if some how it could be the ignition. Just grabbing at anything. I have not yet removed the fuse box but I hate to do that again. It has been years when I installed the roof lights on my 06 and was hard to get it back in place.
Guess Im grounded when it gets dark............

 

[Happy Hummer]

I'm going to suggest the ground needing to be cleaned. Sounds like a resistance has been generated by corrosion.

 

[f5moab]

Ground shown is located at:
In the engine compartment, on left inner front wheel well behind battery

Could have some funk on the Fuse/relay panel connectors.

However the common problem does related to a ground since the ground path is switched dependent up on hi or low beam.

(And not many people realize the dielectric grease is NOT conductive. But lucky for those who think it is when they use it they usually use on circuits that have enough juice to not be a problem.)

One way to test is to tap into the PK or D-BU wires with a temp ground

 

[Hunner]

The ground behind the battery towards the firewall is screwed in with a selftapping fine thread screw. It will not tighten back up after removing to clean. I moved it over to the vertical side of the fender on a bolt with nut clip.
Blew out the fuse box and used contact cleaner on all components having to do with the lights.

Still not working. Maybe the dealer can read the BCM and see if it is talking to the head light?
Guess Im wupped on this one.

 

[rascole]

possible bad connection in the light socket.

 

[f5moab]

No left/right separate control of the headlights via the BCM. BCM closes the HDLP relay, 12 volts is applied to the bulb in left and right assembly, BCM then controls the ground relay, but if one bulb is working ok, that means the BCM gave the correct command to the ground relay (aka HI/LO relay).
Like I suggested jump a ground wire between the ground wire(s) for the defective side and see what happens.
If it is a ground issue it has to be between the bulb to the relay since after the relay the same ground is used for both. Get an ohm meter and check the resistance between the bulbs connectors and the relay connectors for both sides. One will most likely have beaucoup resistance.

But as Rascole states, take a very close look at the connector. Can't speak for the front, but the rear light connectors were absolute garbage and were noted not to allow good contact causing dim light situations or full failure.

If that does not work, you need to take it to the switch back on Kane Creek road and pour some anti-freeze on the connector. Probably won't fix the light issue, but it will bring back some great memories.:thumbs:

 

[Hunner]

ha ha or not so great memories but lesson learned on sneaky heater hose connections!

 

[Mr_Rich]

This is one of those instances when an analog voltmeter works well to troubleshoot this problem. With the headlight switch on I'd check the voltage across the socket and then check voltage from the hot side of the plug to ground. That could tell you which direction in the circuit to chase. Check resistance from ground of the socket to chassis ground; it should be ~0. Start wiggling the harness to see if there's any needle deflection on the meter. Could be an oxidized splice somewhere...
I also noticed on the schematic that you have right and left fuses; 40 & 41. That could be it right there.

 

[Hunner]

Thanks for all the suggestions, I'm trying to do more checking today.

I have now noticed on the dim driver side that both elements are on but very dim. I also have a ghost issue where even with a fully charged battery when turning the ignition it will click the solenoid but not crank. I repeated try and it fires up? Battery is fully charged. Can the ignition switch be at fault?

 

[Mr_Rich]

You need more current to start a vehicle than the current flow through the ignition switch. It sounds like batt. cables/ batt. term issues as described.

 

[Hunner]

Yeah I realize the full current does not go thru the ignition but it energizes a relay somewhere.

Battery terminals are high end hydraulically swedged on several years ago and appear to be solid. Trying to rig a pigtail to do that checking. It is really hard to reach up in there with both hands or connect both ends to check. I would have paid for longer headlight wires!!

 

[Hunner]

After countless times probing and jumping wires and checking fuse on CKT 74 it either did not look blown or I blew it, after I checked it visually. I ohmed it this time and it was blown. Apparently current was backfeeding somehow thru both elements trying to find a path. So at that stage I started looking for the parasitic draw of 200ma. I believe 30ma is normal.

About to cave in when I looked at the side valance on the drivers seat. I had replaced the leather some time ago and added a layer of padding. The way I slide in and up and out is hard on that edge. I noticed the lumbar switch was partially depressed. I took it off and of course two of the plastic tabs with metal push clips broke off.
I used the band saw and trimmed the upper lip off. Better. Then I could see getting in and out could force it down on the switch. That is why it was intermittent. I ground out a bigger hole. Nothing to lose at this point.

I found a wire clip on the seat frame that had a screw mounting it. I replaced that with a longer SS screw thru the valence. I snapped the back half on, screwed the handle back on and think I had it. Checking for a current draw it was 30ma. Need a bigger trim washer.

Tada, drivers side headlight came on bright. The ignition has repeatedly started the engine. I guess my good batteries were recovering from the extra draw until next time I sat on the edge of the seat. All systems go, for now.

When my back straightens out I will clean up the edges and a touch of black paint.

Next I will put back in the second battery, switch and hook up the winch and extra lights.
Weirdest test combo of events I have gone thru.

ps here is a tip, if you can get your hands in there to remove headlight bulb, then you can pull the socket up thru that square hole to get some slack and replace the bulb to test the wires. It has to be removed to stuff the plug back in though.

 

[Traxx]

Good catch Hunner, I will have to file that away. My panel was all broke to heck when I bought mine as well as the cushion being worn out so I replaced them. The panel is just a couple plastic clips and a screw, it's a poor design made worse because people always want to slide off the seats when getting out for some reason. I'm short so I just hop in and fall out.

I put some rubber door trim along the top edge of both panels, that plastic is kind of sharp and eventually wears a big slice in the leather right above that hump where the switches are.

 

[Hunner]

Good idea about the edge trim. I cut mine back just past that curved lip.

The height of mine makes it so I sort of slide over that edge. Getting out alot when wheeling wore the edge blue denim after awhile but the new seat OEM fit nice. I got some seat bottom covers now that allow my rear to get some air in the hot weather. I really did not want leather and tried to get a special edition that was the only way to get an Alpha without leather. About that time American Axle went on strike and those were cancelled also. Oh well.

 

[alrock]

I was going to trim mine but instead I just added screws to the panel to the metal underneath. That keeps the plastic from flexing into the switch.

I agree, that was a great catch!

 

[4speedfunk]

Good lord. This is worse than a Jaguar.

 

[kk07h3]

Hunner, did you find any improvement with the ultra stars?

 

[alrock]

Good lord. This is worse than a Jaguar.

Them's fighting words!

 

[Hunner]

ehhh I don't know since Ford and TaTa Motors took them over they quit using dirtdobber nests for Lucas fuse holders.

 

[Hunner]

Since all that was going on I have reinstalled the ultra stars. They work. I pulled the left headlight fuse and it goes dim but not out. So part of the problem was missing the slightly blown fuse. Ohm meter solved that when I finally redundantly rechecked it all. So I was chasing a combination of things, plus causing part of it by test probing.