Inner peace and the art of getting my damn taillight to work!
12-19-2003, 08:31 PM
#1
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Inner peace and the art of getting my damn taillight to work!
Having finally finished finals, loaded up my dirty laundy, and headed for home from college, I was in a pretty good mood. Sure it was getting late, but traffic was actually light and I was enjoying the drive. Inner peace was high.
Then, like the annoying little creature it is, my electrical gremlin friend decided to show up. Inner peace is dropping. Let me explain:
The passenger side rear taillights (not the brake lights, or reverse, or turn signals) have a mind of their own. They work sometimes. They don't others. Every other damn light on the car works ALL the time. I get the pod warning all the time, but I usually just ignore it as the lights work most of the time.
Well suffice to say that today they weren't, and I got pulled over less then a mile from my house!
However, the cop was cool and just wanted to make sure I knew I had two bulbs out, so I thanked him and we parted ways. 
Inner peace largely unaffected.
So having nothing better to do today, I rolled out of bed around 2 o'clock and decided to fix those nasty little bulbs. So I changed EVERY bulb on the rear of the car to new, correct spec ones, checked the sockets which didn't seem too bad, and double-checked the fuse even though the front-right lights all worked. Of course, the damn lights still don't work!
Inner peace is low right about now.
So before I go tearing apart my interior panels to check the grounds, is there anything else I can do? Remember, it works sometimes, and I've already changed all the bulbs. This is really starting to frustrate me, as it has been going on for a few months.
All help is appreciated.
-Jason
Then, like the annoying little creature it is, my electrical gremlin friend decided to show up. Inner peace is dropping. Let me explain:
The passenger side rear taillights (not the brake lights, or reverse, or turn signals) have a mind of their own. They work sometimes. They don't others. Every other damn light on the car works ALL the time. I get the pod warning all the time, but I usually just ignore it as the lights work most of the time.
Well suffice to say that today they weren't, and I got pulled over less then a mile from my house!
However, the cop was cool and just wanted to make sure I knew I had two bulbs out, so I thanked him and we parted ways. Inner peace largely unaffected.So having nothing better to do today, I rolled out of bed around 2 o'clock and decided to fix those nasty little bulbs. So I changed EVERY bulb on the rear of the car to new, correct spec ones, checked the sockets which didn't seem too bad, and double-checked the fuse even though the front-right lights all worked. Of course, the damn lights still don't work!
Inner peace is low right about now. So before I go tearing apart my interior panels to check the grounds, is there anything else I can do? Remember, it works sometimes, and I've already changed all the bulbs. This is really starting to frustrate me, as it has been going on for a few months.
All help is appreciated.
-Jason
12-19-2003, 09:55 PM
#2
Jason,
We have a mutual problem.
As to the cure...
I have:
1. Cleaned to bright surface every socket.
2. Every ground including the seperate speaker grounds. don't forget the conglomeration of grounds above the fuse panel (in the vicinity of the Lamp Control Unit aka LCU swapped out the LCU too -not cheap-.
3. Cleaned every connector in the car down to the brake pad warn connectors. Connectors that looked marginal were removed and new ones soldered in.
4. Replaced all the fuses, and all of the bulbs with exception of fogs and headlights. Fuses were replaced with the glass Euro torpedo type - Walmart- they fit the fuse holders perfectly btw. Cleaned both the fuse holders and the spagetti connections on the back side of the board and back side of all relays as well.
5. Chassis grounds, coil grounds, disassembled all interior and side marker lights to clean any sockets/leads/contacts.
6. Replaced window, sunroof, and wiper switches.
7. Pulled and cleaned the door marker pressure switches.
8. Diconnected the power ant. -don't use it.
9. Fixed the wiring where the paint shop assasins ripped the rear light assemblies out before they could figure the rear facia had to come off.
They used sheet rock screws to remount but at 2 1/2" long they eventually cut thru and shorted when ever I'd hit a bump, a vibe...
Bottom line I'm not trying to scare you off the attempt ( though misery does like company ) .
Id suggest a good multimeter to see if:
1. Your getting juice back there.
2. If there is more or less resistance to one side or the other.
3. Use one of those probe type continuity testers and test the wiring front to rear on that circuit don't forget to energize the lights.
4.Check the archives Randy and others should be able to guide you to the correct wires.
As for me ... with all of the above work i get warns of brake pads, brake pressure, taillights with the never ending blinking master caution.
left window motor is dragging, sunroof motor needs a look see and I don't drive at night!
FWIW when I do a long trickle charge 12-18 hours, all the warns go away when I reconnect battery, however some or all return within a day or three.
Good luck.
We have a mutual problem.
As to the cure...
I have:
1. Cleaned to bright surface every socket.
2. Every ground including the seperate speaker grounds. don't forget the conglomeration of grounds above the fuse panel (in the vicinity of the Lamp Control Unit aka LCU swapped out the LCU too -not cheap-.
3. Cleaned every connector in the car down to the brake pad warn connectors. Connectors that looked marginal were removed and new ones soldered in.
4. Replaced all the fuses, and all of the bulbs with exception of fogs and headlights. Fuses were replaced with the glass Euro torpedo type - Walmart- they fit the fuse holders perfectly btw. Cleaned both the fuse holders and the spagetti connections on the back side of the board and back side of all relays as well.
5. Chassis grounds, coil grounds, disassembled all interior and side marker lights to clean any sockets/leads/contacts.
6. Replaced window, sunroof, and wiper switches.
7. Pulled and cleaned the door marker pressure switches.
8. Diconnected the power ant. -don't use it.
9. Fixed the wiring where the paint shop assasins ripped the rear light assemblies out before they could figure the rear facia had to come off.
They used sheet rock screws to remount but at 2 1/2" long they eventually cut thru and shorted when ever I'd hit a bump, a vibe...
Bottom line I'm not trying to scare you off the attempt ( though misery does like company ) .
Id suggest a good multimeter to see if:
1. Your getting juice back there.
2. If there is more or less resistance to one side or the other.
3. Use one of those probe type continuity testers and test the wiring front to rear on that circuit don't forget to energize the lights.
4.Check the archives Randy and others should be able to guide you to the correct wires.
As for me ... with all of the above work i get warns of brake pads, brake pressure, taillights with the never ending blinking master caution.
left window motor is dragging, sunroof motor needs a look see and I don't drive at night!
FWIW when I do a long trickle charge 12-18 hours, all the warns go away when I reconnect battery, however some or all return within a day or three.
Good luck.
12-19-2003, 11:26 PM
#5
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First question: When the tail lamps are out, does the right rear side marker lamp burn? If so, the problem has to be in the tail light socket, its ground, the short wire to the connector in the hatch area, or that connector.
Second question: When the tail lamps are out, does the right front parking light burn? If so, the problem is not in the light switch or fuse (#41).
Catching an intermittent gremlin can be a very frustrating matter. It might be worth making a simple test rig to trap him...
Go to Walmart, look in the Chrismas light section and find the spare bulbs. What you are looking for is a package of little 12 volt colored bulbs, with two tiny wire leads on each bulb. While you are there, go to the automotive section and buy a spool of speaker wire - the thin, cheap stuff with clear insulation and small solid wire.
Cut a ten-foot section of speaker wire. Solder one of the little 12 volt Christmas lights to one end, and use heat-shrink, RTV or electrical tape to insulate the connections and help hold the bulb to the wire. Cut a four-foot piece of wire, and solder a bulb to it the same way.
You now have two low-power 12 volt test lamps of different colors, and the parts to make several more. These lights don't pull enough power to overload any circuit, nor to burn your upholstery.
Run the short wire to terminal S23. That is, the third connector up on the right row of Plug S, which I think is the sixth one from the right end of the row of plugs on your car. There should be a gray/red wire in this position. Split the speaker wire, and hook one side to the ground connections near the panel, and the other side to S23. You may be able to just push the bare end of the wire into the plug. Put the test bulb where you can see it while you are driving. The bulb should light when the lights are on. Let's call this Bulb 1.
Run one of the long wires to the rear of the car, and hook one end to the brown ground wire at the connector on the light harness that is in the right rear hatch area. Hook the other side to the gray/red wire in the connector. Put the test bulb, which we will call Bulb 2, next to Bulb 1.
Drive the car until you lose the tail lights.
If Bulb 1 is out, the problem is before Terminal S23, so it is in the connections behind the Central Power Panel.
If Bulb 1 is lit, but Bulb 2 is out, the problem is probably in the Bulb Check Unit or its connections, or in the ground at the rear. Try moving the test lead ground wire to a good chassis ground. If Bulb 2 now burns, but the tail lamps don't, the problem is the ground.
If both Bulb 1 and Bulb 2 are lit, the problem is in the socket or its connections.
Hope this helps...
Second question: When the tail lamps are out, does the right front parking light burn? If so, the problem is not in the light switch or fuse (#41).
Catching an intermittent gremlin can be a very frustrating matter. It might be worth making a simple test rig to trap him...
Go to Walmart, look in the Chrismas light section and find the spare bulbs. What you are looking for is a package of little 12 volt colored bulbs, with two tiny wire leads on each bulb. While you are there, go to the automotive section and buy a spool of speaker wire - the thin, cheap stuff with clear insulation and small solid wire.
Cut a ten-foot section of speaker wire. Solder one of the little 12 volt Christmas lights to one end, and use heat-shrink, RTV or electrical tape to insulate the connections and help hold the bulb to the wire. Cut a four-foot piece of wire, and solder a bulb to it the same way.
You now have two low-power 12 volt test lamps of different colors, and the parts to make several more. These lights don't pull enough power to overload any circuit, nor to burn your upholstery.
Run the short wire to terminal S23. That is, the third connector up on the right row of Plug S, which I think is the sixth one from the right end of the row of plugs on your car. There should be a gray/red wire in this position. Split the speaker wire, and hook one side to the ground connections near the panel, and the other side to S23. You may be able to just push the bare end of the wire into the plug. Put the test bulb where you can see it while you are driving. The bulb should light when the lights are on. Let's call this Bulb 1.
Run one of the long wires to the rear of the car, and hook one end to the brown ground wire at the connector on the light harness that is in the right rear hatch area. Hook the other side to the gray/red wire in the connector. Put the test bulb, which we will call Bulb 2, next to Bulb 1.
Drive the car until you lose the tail lights.
If Bulb 1 is out, the problem is before Terminal S23, so it is in the connections behind the Central Power Panel.
If Bulb 1 is lit, but Bulb 2 is out, the problem is probably in the Bulb Check Unit or its connections, or in the ground at the rear. Try moving the test lead ground wire to a good chassis ground. If Bulb 2 now burns, but the tail lamps don't, the problem is the ground.
If both Bulb 1 and Bulb 2 are lit, the problem is in the socket or its connections.
Hope this helps...
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12-20-2003, 08:04 PM
#9
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Wally,
In reply to first question, when the taillight goes out both the taillight itself and the sidemarker light goes out. Never one or the other. Always both.
Second Q, yes the front parking light burns.
Thanks for the reply!
-Jason
In reply to first question, when the taillight goes out both the taillight itself and the sidemarker light goes out. Never one or the other. Always both.
Second Q, yes the front parking light burns.
Thanks for the reply!
-Jason
12-21-2003, 09:10 PM
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Quick update:
I haven't tried Wally's diagnostic yet (sounds too complicated for me at the moment
), but I did some more testing and am even more confused.
Using a voltagemeter, I checked the sockets of the suspect taillights, and found that when neither has a bulb in, both show power. But when I put in a bulb, nothing happens. So then I tried putting a bulb just in the side one and testing the rear- and got nothing again. Took the bulb out and all of a sudden I had power again!
So I'm very confused. My Fluke shows power at both sockets, but I can't get any light!?! The only thing I can think of is a thurough cleaning of the contacts, but I doubt that will fix the problem.
All help is appreciated!
-Jason
I haven't tried Wally's diagnostic yet (sounds too complicated for me at the moment
), but I did some more testing and am even more confused. Using a voltagemeter, I checked the sockets of the suspect taillights, and found that when neither has a bulb in, both show power. But when I put in a bulb, nothing happens. So then I tried putting a bulb just in the side one and testing the rear- and got nothing again. Took the bulb out and all of a sudden I had power again!
So I'm very confused. My Fluke shows power at both sockets, but I can't get any light!?! The only thing I can think of is a thurough cleaning of the contacts, but I doubt that will fix the problem.
All help is appreciated!
-Jason
12-21-2003, 09:43 PM
#11
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So what you're saying is that you are making a "good circuit" by connecting to the socket and a good ground. If that's the case, then your problem is probably the ground within your socket
12-22-2003, 12:06 AM
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Jason,
First, Wally is always right - even though it is sometimes complicated.
Looking at the wiring diagram for the 86, all of the lights back there share a common ground. This includes the backup, stop, clearance (tail), flasher, and side lamps. Since all the others work, chances are your ground is ok. The interesting interplay between the tail light and the side lamp is that they share a common power feed.
Somewhere in the back pf your car is a plug with 7 connectors that plugs into the tail lamp unit wiring harness. It may be behind the side panel with is a pain to remove (first pull the back seat.....). Pin 4 of this harness feeds both of those lamps. I'd bet something funky is going on there but it will likely take some fiddling to find out.
First, Wally is always right - even though it is sometimes complicated.
Looking at the wiring diagram for the 86, all of the lights back there share a common ground. This includes the backup, stop, clearance (tail), flasher, and side lamps. Since all the others work, chances are your ground is ok. The interesting interplay between the tail light and the side lamp is that they share a common power feed.
Somewhere in the back pf your car is a plug with 7 connectors that plugs into the tail lamp unit wiring harness. It may be behind the side panel with is a pain to remove (first pull the back seat.....). Pin 4 of this harness feeds both of those lamps. I'd bet something funky is going on there but it will likely take some fiddling to find out.