Weird lighting issue, bulbs replaced and fuses checked...

[07liftback]

This started happening a couple of days ago where my driver side tail light, center tail light, front signal lights, and side marker lights don't come on when the lighting stalk is turned on. The only lights still working is the passenger tail light, the front passenger corner light, and my headlights.

I just replaced both tail light bulbs with LED bulbs a few months ago and am running a HID kit with a relay. I'm gonna try unplugging the HID kit to see if the problem persists but I've unplugged the battery and replugged it to try to reset the computer to see if it did anything and nothing...

I've checked all the fuses from the the fuse box under the hood as well as the fuses behind the coin compartment and the fuses that face the driver side floor. I'll soon be checking these lights with a multimeter but I highly doubt it's the bulbs that are burnt out because the hazard light switch seems to get them to light up and flash. My brake lights seem to work fine when I apply the brakes too.

I didn't find any blown fuses. Would there be an issue with a relay? Why would only one side light up and not the other? Could it be an issue with my steering column light stalk?

[bairjo]

has anything been done to the wiring like adding a trailer hitch plug. Could be a grounding issue.. regardless of what I think, CTScott will eventually be responding to this...it's right up his alley of expertise. Me...I'm just a boiler guy.

[07liftback]

Originally Posted by bairjo

has anything been done to the wiring like adding a trailer hitch plug. Could be a grounding issue.. regardless of what I think, CTScott will eventually be responding to this...it's right up his alley of expertise. Me...I'm just a boiler guy.

Nope, haven't messed with any electrical components besides replacing my spark plugs with NGK copper plugs. I had NGK platinum plugs before but see no reason as to why it would be correlated with my weird lighting issue...

[07liftback]

So I was checking the service manual and although it could be a short somewhere in the circuit, it appears it could also be the T-LP relay which controls the "Tail light, illumination parts, and license plate lights". Well my dash and other interior lights work fine and the license plate light works fine as well.

I'm going to follow the grounding wire for the left tail light and center tail light as well as check the harness connection to ensure it's stable. It seems a bit sudden that all of a sudden these lights just cut out and if it were a fuse, I would assume all tail lights wouldn't work as well as the front corner lights.

I just need help locating this "T-LP relay" and would like to find out if that could be a possible cause of failure.

[CTScott]

My bet is the HID kit being the issue, but the T-LP relay could be the problem (either by cause or by effect of the HID kit). The T-LP relay is located in the smaller relay box on the passenger side, under the hood.

[07liftback]

Originally Posted by CTScott

My bet is the HID kit being the issue, but the T-LP relay could be the problem (either by cause or by effect of the HID kit). The T-LP relay is located in the smaller relay box on the passenger side, under the hood.

Thanks CTScott! I'll check it out first thing in the morning. My hid kit is connected to a relay harness so it draws power directly from the battery once the lights are switched on. It very well could have been the culprit since it only uses the connection from the driver side headlight harness and not the passenger side. I've unplugged the hid kit completely and it still had no effect on the lights. I even pulled the fuse out, and yet again, nothing.

Could the leds in the tail lamp be an issue as well?

[CTScott]

Originally Posted by 07liftback

Thanks CTScott! I'll check it out first thing in the morning. My hid kit is connected to a relay harness so it draws power directly from the battery once the lights are switched on. It very well could have been the culprit since it only uses the connection from the driver side headlight harness and not the passenger side. I've unplugged the hid kit completely and it still had no effect on the lights. I even pulled the fuse out, and yet again, nothing.

Could the leds in the tail lamp be an issue as well?

You could try swapping back the tail bulbs, but they shouldn't cause the behavior you are seeing.

[07liftback]

Originally Posted by CTScott

You could try swapping back the tail bulbs, but they shouldn't cause the behavior you are seeing.

Hmm, I tried pulling that relay but it did nothing. It's a grey one correct? Located in the tiny fuse box right under the passenger side headlight? I believe it only controls the dash lights. I tested the tail light socket on the side that's out and there are 3 prongs. The green wire seems to not be providing power but I'm getting a 12v reading from the red and the black one. Does this mean the ground is loose somewhere?

[07liftback]

Okay, I'll attach some pics I pulled from the service manual. I pulled every relay behind the coin compartment one by one with zero results in disabling the tail lights and front marker/ corner lights. I'll check the fuse box facing the ground on the driver side tomorrow for relays but last I checked, they were only fuses.

According to the service manual, I'm convinced it's either two grounding points that have become disconnected or the relay has become faulty. Still trying to find the darn T-LP relay and would also like some guidance as to where the grounding points for the tail lights and marker lights are.

[CTScott]

Originally Posted by 07liftback

Hmm, I tried pulling that relay but it did nothing. It's a grey one correct? Located in the tiny fuse box right under the passenger side headlight? I believe it only controls the dash lights. I tested the tail light socket on the side that's out and there are 3 prongs. The green wire seems to not be providing power but I'm getting a 12v reading from the red and the black one. Does this mean the ground is loose somewhere?

The relay is a large (1" x 1" x 1") located in the small relay box that is mounted to the strut tower on the passenger side. There should not be a relay under the passenger headlight.

[07liftback]

Thanks for the quick reply CTScott! I captured a pic of it earlier, would it happen to be this one? There was only one fuse in that tiny box and the back side of it said H-LP I believe.

[CTScott]

That is the correct one.

[07liftback]

Originally Posted by CTScott

That is the correct one.

It seems to have no effect on the one tail light that's still on nor the passenger side corner light. Do you know where the grounding points are located? Again, I appreciate all the help!

[CTScott]

The white/black wire on the tail light and the side market the is the ground wire. You could try jumping that terminal on the connector to a solid chassis ground.

Did you per chance try swapping out the LED tails?

[07liftback]

Originally Posted by CTScott

The white/black wire on the tail light and the side market the is the ground wire. You could try jumping that terminal on the connector to a solid chassis ground.

Did you per chance try swapping out the LED tails?

Not yet, but I'll try tonight. Yea, I was thinking of just grounding the wire and seeing if I can just fix it by wiring in a new ground point to the system. Will keep you updated. Thanks!

[07liftback]

Okay, quick update... Turns out the cheap led bulb I bought had become defective and no longer worked with my low beams so that's one issue out of the way. Now it appears the center tail light does not receive any power whatsoever. I tested the two prongs with zero results and tried to ground each prong to the chassis which yielded zero voltage or continuity yet again. Side markers, front corner lights and the center tail light still won't come on when the headlight switch is turned.

[CTScott]

Originally Posted by 07liftback

Okay, quick update... Turns out the cheap led bulb I bought had become defective and no longer worked with my low beams so that's one issue out of the way. Now it appears the center tail light does not receive any power whatsoever. I tested the two prongs with zero results and tried to ground each prong to the chassis which yielded zero voltage or continuity yet again. Side markers, front corner lights and the center tail light still won't come on when the headlight switch is turned.

By "center tail" I assume you mean the light at the top of the hatch window? If so, that is just a third brake light and it does not come on with the lights.

[07liftback]

Originally Posted by CTScott

By "center tail" I assume you mean the light at the top of the hatch window? If so, that is just a third brake light and it does not come on with the lights.

Yea, the high mounted stop light. Cool, so my car's now safe from fix-it tickets. Thanks CTScott! Hmm, still wondering what's up with the lights in the front. Probably a short...