Patrick - LED Taillight problems

[patrickt]

Originally Posted by DanEC

I'm going to have to think about that one. I'm not too inclined to start pulling Bob's nice soldered and crimped connections apart especially at the crowded fuse panel connections. I could eventually really have a problem then. I may have to look at pulling some plugs apart to isolate the circuits.

All for tonight.

That's understandable. Here's a lower impact method: On the driver's side light fixture there are red wires running to that light. One is a source feed, the other runs to the license place light and the other tail light. Mark each one of those wires so you know which goes to which, then cut them and tape off all ends. See if your turn signals now function properly. If they do, one of those cut ends will be flashing 12v and that wire leads to the fault. In fact, one of those cut ends will be flashing regardless, and that wire points to the fault.

[DanEC]

I'm not in the mood to start cutting up my wiring just to make LEDs work. I have some other ideas to try. With flashers on and parking lights off, I'm going to pull both red leads to the rear tail lights and see which side is hot (or if both are). I suspect it's going to be the bulb side, bleeding over from the flasher circuit - otherwise why would the license plate and dash lights be blinking and not just lit up.

I think I will pick up a 1157 socket and temp wire it to the pass side tail light flasher circuit with a 1157 bulb and see if the extra load makes any difference.

Then look at the major harness connection plugs - especially #27. When assembling the car I had a parking light problem at the front and finally found two wires mispositioned when the harness was assembled. Reversing those wires to match the wiring diagram straightened out all my lighting problems. But - maybe there is still something out of whack there.

I can't see how the dash light circuit could be backfeeding anything as it's basically a dead end circuit and supposedly doesn't run through any harness connections so I think I can ignore it.

See what happens.

[patrickt]

Originally Posted by DanEC

Then look at the major harness connection plugs - especially #27. When assembling the car I had a parking light problem at the front and finally found two wires mispositioned when the harness was assembled. Reversing those wires to match the wiring diagram straightened out all my lighting problems. But - maybe there is still something out of whack there.

I can't see how the dash light circuit could be backfeeding anything as it's basically a dead end circuit and supposedly doesn't run through any harness connections so I think I can ignore it.

Reversed pins will do it... for sure. The reason we "walk back" from the end of the circuit (the end of the circuit is at the pulled fuse), and seemingly take unnecessary steps, is that the underlying portions of the circuit are not absolutely distinct. For instance, the panel lights are on the same line as one of the front parking lights, but not the other.

But you know that you're getting a flashing 12v at fuse #6 with the fuse out. That should never happen. That's the fault, and it's traceable. I think it's going to end up being a faulty rear fixture, or a misaligned pin alignment in a plug.

[Xack]

Originally Posted by DanEC

I'm not in the mood to start cutting up my wiring just to make LEDs work. I have some other ideas to try. With flashers on and parking lights off, I'm going to pull both red leads to the rear tail lights and see which side is hot (or if both are). I suspect it's going to be the bulb side, bleeding over from the flasher circuit - otherwise why would the license plate and dash lights be blinking and not just lit up.

I think I will pick up a 1157 socket and temp wire it to the pass side tail light flasher circuit with a 1157 bulb and see if the extra load makes any difference.

Then look at the major harness connection plugs - especially #27. When assembling the car I had a parking light problem at the front and finally found two wires mispositioned when the harness was assembled. Reversing those wires to match the wiring diagram straightened out all my lighting problems. But - maybe there is still something out of whack there.

I can't see how the dash light circuit could be backfeeding anything as it's basically a dead end circuit and supposedly doesn't run through any harness connections so I think I can ignore it.

See what happens.

For your peace of mind and sanity, you should troubleshoot this to figure it out. In the end you'll fix something which could possibly cause you issues later or cause something not to work the way it should as you drive your car.

Quite possibly there is something shorted or connected wrongly. The connectors should be invistigated for pins folded over or things just connected up wrong or switched. Assume nothing, verify everything. Divide and conquer.

I wish you well in this and I'm following.
Xack

[patrickt]

The beauty of this problem is that it is not intermittent. It happens every time. That makes it soooooooo much easier to trace. A few years ago, I had an intermittent problem on my ERA. To diagnose it, I had little 12v indicator lights strung up all over the circuit and taped to the dash. When the problem occurred, I quickly looked at the dash to see what lights were lit and what weren't. That told me where the problem was (and where it wasn't), but, boy, that was a PITA.

[DanEC]

Originally Posted by Xack

For your peace of mind and sanity, you should troubleshoot this to figure it out. In the end you'll fix something which could possibly cause you issues later or cause something not to work the way it should as you drive your car.

Quite possibly there is something shorted or connected wrongly. The connectors should be invistigated for pins folded over or things just connected up wrong or switched. Assume nothing, verify everything. Divide and conquer.

I wish you well in this and I'm following.
Xack

I'm still thinking it's a load issue, either from the Pilot bulbs or my flasher unit. I'm not going to cut the harness. Anytime I see an old car with a splice in it I think - there's another car some Bubba butchered up. But, I'll hunt and peck around some more and see what I can turn up. Thanks