Puzzling Tail Lamp Problem

[squarehat]

I have a '96 ES with a puzzling tail lamp problem. I get a tail lamp out indicator light on the dash when first turning on the lights, and going around back reveals a non-illuminated taillamp on the passenger side (the 96 ES has two dual-filament stop/tail lamps on each side). I have replaced both bulbs on each side, along with the license plate bulbs on each side (haven't touched the reverse lights or turn signals yet).

Here's the puzzling part. After about 15 minutes of driving, the taillamp out indicator goes out, AND the bulbs all work normally again (I'ved hopped out of the car with the engine still running/lights on to validate this).

What could be the issue here? Bad wiring harness on the passenger side? Or could it be a more serious electrical problem (perhaps the system doesn't get enough voltage to run all of the lamps until the alternator has been running a while, though I'm not noticing any dimming of the headlamps, or problems with the audio or climate control, nor any other warning lamps). Changing bulbs doesn't seem to do much help...

Thanks!

[SKperformance]

Odd i thought the system only resets after the car is shut down

check the connections and wires that go along the inside of the ligths to see if the wires are being crimped against the body because they were not properly reinserted inside the channels to hold them

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[amf1932]

Even though the bulbs are good, there could be oxidation built up in the sockets. This added resistance could sometimes cause this problem. I would try cleaning the contacts in the sockets using an electrical contact cleaner and/or sandpaper.

[squarehat]

Thanks for the input, guys. The wires are neatly tucked, and the insulation is in perfect shape (in fact, I just pulled/replaced both lamps again yesterday.) The oxidized contact hypothesis is definitely a possibility. Perhaps something happens once the circuit heats up, causing the connection to be good enough to light the lamp back up (or it randomly gets jostled into electric contact somewhere along the drive). Hopefully I will have time to take the assembly apart and clean the contacts this weekend. I'll keep everybody posted with the results.

[squarehat]

Alright. I pulled every single bulb out of both taillamp assemblies, and used the contact cleaner. The tail/brake lamps are working fine now. Unfortunately, after a day of things working perfectly, my left rear turn signal now doesn't work. I guess I'll be dismantling everything again tomorrow and changing the turn signals on both sides.

Is the change in resistance (or voltage, I'm no electrical engineer :D ) from the other bulbs working again "shocking" the turn signal and knocking it out? There seems to have been a domino effect over the past month--changing two taillamp bulbs knocked my license plate bulbs out, so I changed both license plate bulbs and the other two tail/stop bulbs. Then after replacing the license plate bulbs, I had problems with both tail/stop bulbs on the passenger side working intermittently. I'm wondering if I should change the backup lights and the two little wedge sidemarker bulbs while I'm at it tomorrow, so that I can have fresh bulbs all around, and not worry about it anymore.

Though I've gotten quite proficient at neatly removing/replacing the rear trunkliner :D

[amf1932]

Very Strange. Make sure you're using the proper type of bulbs. Some sockets use 2 filament types. Also, the fact that they started working properly again leads me to believe that there still is a problem with the contacts in the sockets or bulbs. I doubt whether "shocking" the turn signal is knocking out the operation. The resistance of the turn signal is a balanced operation, and if any part of this equation is wrong they'll either flash more quickly, or less quickly, or not at all. The turn signal bulbs have bayonet bases with uneven tangs to prevent you from putting them in backwards. If by chance you forced them into the socket the contacts will not line up and thereby prevent a good contact. I think that Radio Shack sells a spray on contact cleaner & conditioner. I use "Caig Brand ProGold G5 Spray" for certain electronic components......but this product is pretty expensive.

[SKperformance]

check the wires

you might have a defective one

turnt eh signals on and remove the light and play with the wires

[squarehat]

I'm right with you, amf I used the Radio Shack contact cleaner spray on all of the sockets this weekend. I replaced both turn signals this morning (single filament 1156 bulbs) and both sidemarkers (168 wedge base bulbs). The license plate bulbs (168 wedge) and all 4 stop/tail lamps (1157 dual filament) have been all replaced over the past month. All bulbs are the proper type, properly secured, and properly sealed in their sockets.

As of now, all systems are go, knock on wood :D . Immediately after I replaced the left 1156 turn signal bulb, I hopped in and flipped on the hazards, and it worked normally again. All tail/sidemarker brake lamps are good, too, and I have not seen the dreaded yellow warning light since using the contact cleaner (when the turn signal blew, I got the hyper-blinker arrow instead).