Tail Light Turn Signal Issues

[bliss]

I have an older ERA....

Lights OFF: I'm not getting a 'flash' from the right tail light (right turn signal) (left is fine).

Lights ON: both tail lights do come on, but no 'flash' from the right or left tail light.

The front turn signals work fine - light off and on.
_____

Does this sound like strictly a wiring issue or are there parts to be checked, also?

Any input will be appreciated.

[DanEC]

You have my condolences. If you feel like reading, these two threads explore just about every tail light turnsignal failure mode imaginable. Patrick gave a lot of hints and trouble-shooting tips throughout in them .

Also, Bob's Electrical Primer troubleshooting guide is very helpful. I think you can access it from their website. I will try to find it and post a link.

AAaagghhh - still no brake lights or turn signals!!

Bob - Turn signal and brake light problems #782

Dan

[DanEC]

Here is Bob's electrical troubleshooting guide. Since you have an older ERA you may want to give him a call once you have done a little troubleshooting.

http://www.erareplicas.com/427man/wiring/wprimer.pdf

[bliss]

Thanks, Dan - especially for the condolences.

Lots of info on those threads.

[patrickt]

Originally Posted by bliss

I have an older ERA....

Lights OFF: I'm not getting a 'flash' from the right tail light (right turn signal) (left is fine).

Lights ON: both tail lights do come on, but no 'flash' from the right or left tail light.

The front turn signals work fine - light off and on.
_____

Does this sound like strictly a wiring issue or are there parts to be checked, also?

Any input will be appreciated.

The first thing I would do is switch the bulbs, both up front and in the rear. See if any changes occur. If not, then you know it's in the circuitry and you'll just have to work your way back up. There's really not much there in the turn signal circuitry. It's pretty easy to diagnose. But switch the bulbs and report back.

[bliss]

Patrick - bulbs switched. No variance.

Also, The old and new left rear bulb works fine in the right rear socket - so, there is something up with the left rear flash circuitry, plus the circuitry on both sides (rear only) when the lights are on.

BTW, nothing is easy for me.

Thanks.

[patrickt]

Originally Posted by bliss

BTW, nothing is easy for me.

Thanks.

That's ok -- it's not that tough. Now, examine the two fast-blow fuses that are under the dash mounted on the steering column area. If one is obviously blown, then that's the problem. If they appear to be good, then pull them both out and switch them, and put them back in. Then try everything and see if there is any change.

[bliss]

Originally Posted by patrickt

That's ok -- it's not that tough. Now, examine the two fast-blow fuses that are under the dash mounted on the steering column area. If one is obviously blown, then that's the problem. If they appear to be good, then pull them both out and switch them, and put them back in. Then try everything and see if there is any change.

Patrick - well, as a read your post I was thinking - WOW, I can check that and perhaps eliminate the problem myself - well, I didn't find anything that looks like a fuse attached to the steering column under the dash.

Are the mentioned fuses separate from the array of fuses attached to the firewall inside the engine area?

[patrickt]

Originally Posted by bliss

Patrick - well, as a read your post I was thinking - WOW, I can check that and perhaps eliminate the problem myself - well, I didn't find anything that looks like a fuse attached to the steering column under the dash.

Are the mentioned fuses separate from the array of fuses attached to the firewall inside the engine area?

Yes, these are two fuses that are separate from the fuse blocks in the engine compartment. These two fast-blow fuses are located on the steering column, right above where your knees are when you are driving. First, examine them, then if they look like they're ok (meaning one is not blackened with an obviously blown filament), then pull them both out and switch them, then put them back in. See if that makes any changes. And while you're doing that, with the ignition key on, put your foot on the brakes and tell me if both, or only one of the brake lights is coming on.

What ERA number is your car? Perhaps the really early ones didn't have the fuses. I'll check the schematic for your car number and see.

EDIT -- It looks like they put the fuses in around car 335.

[Cobra #3170]

Originally Posted by bliss

I have an older ERA....

Lights OFF: I'm not getting a 'flash' from the right tail light (right turn signal) (left is fine).

Lights ON: both tail lights do come on, but no 'flash' from the right or left tail light.

The front turn signals work fine - light off and on.
_____

Does this sound like strictly a wiring issue or are there parts to be checked, also?

Any input will be appreciated.

Make sure both tail light sockets are properly grounded, in fact you could make up a jumper with alligator clips to ground both sockets temporarily to test the system for operation. I don't know about ERA's but have seen similar problems on old Corvette's.

[bliss]

Originally Posted by Cobra #3170

Make sure both tail light sockets are properly grounded, in fact you could make up a jumper with alligator clips to ground both sockets temporarily to test the system for operation. I don't know about ERA's but have seen similar problems on old Corvette's.

I switched the sockets - left to right - works fine - therefore, both sockets work on the right side, but not on the left side (flash)

Thanks for chiming in.

[kevins2]

Agree with checking the ground. When I built my car I disconnected the grounds to install the carpet and forgot to hook them up - similar symptoms to what you're describing and easy enough to check.

[strictlypersonl]

At one time, the front twist-off lights were coming through with sockets for even-height pins. That's where 1176 bulbs were required. Since the bulb can be inserted "backwards", you must check that the parking lights are on the less-bright filament. Otherwise, turn them 180 degrees in the socket.

[bliss]

The 1176 works just fine, thanks.

[patrickt]

Originally Posted by bliss

The 1176 works just fine, thanks.

Hurray. Now the only other things you need to diagnose the problem are a simple $10 Volt Meter from Lowes, Radio Shack, or the like, and a nice long piece of wire, say about ten feet long, with the thickness of a typical lamp cord, and put alligator clips on both ends of it.

All we will be doing is to first get the signal working, and then we'll do a voltage drop check along both sides of the circuit. This is very easy to do and, for anyone else that reads this thread, it will be an insight in to how to diagnose a misbehaving circuit by measuring voltage drop (both on the hot side of the circuit and on the ground side of the circuit).

[patrickt]

I disconnected my trailer relay and measured the voltages, drops, and tested it along the signal/brake light circuit, both while it was operational and while it was apart. (This was not a big a job, it took about ten minutes.) I also tested it using a really simple 12v test light, since it's almost impossible to hurt anything on a car's circuit using a test light -- so that's what I'm going to recommend you start with.

So, your first step to fix the circuit is to carefully cut back the insulation from the green and yellow wires that come off of the "trailer side" of the trailer relay (not the "car side" of the trailer relay that also has the red wire going in to it). Do not cut the wires in two, just shave the insulation off of them. Then, with those two wires exposed, attach your 12v test light to a good ground and then to each wire, one at a time. Test your brakes and turn signals with the light attached to each wire. See if the test light behaves correctly or if it misbehaves like your car's lights do. Put it through all the paces by testing it with other lights, like your headlights, on as well. Take notes and report back.

There's an unusual aspect of the trailer relay that you should be aware of: There is a small amount of voltage that "bleeds" over from one turn signal output to the other. A volt meter will picks it up and your test light (mine did) might pick it up as well. It's not enough to fire off your car's lights though. What this means is that if you have your test light on the yellow wire, and the turn signal is flashing the green wire, you may see a very dim flash on your test light when it's attached to the yellow light. This is normal.

Digital volt meters are not the best for dealing with flashing circuits. An old fashioned meter with a dial and a needle is better, and a test light is best.

[bliss]

I'm on the case!

[patrickt]

Originally Posted by bliss

I'm on the case!

OK, I'll split my fee then.

[patrickt]

Originally Posted by bliss

I'm on the case!

OK... are we making any progress yet? The whole diagnosis part should only take about ten minutes or so.