Tail Light Turn Signal Issues

[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.

[bliss]

Originally Posted by patrickt

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.

Thanks - mine ERA is 098 - very early - so, no separate fuses?

[patrickt]

Originally Posted by bliss

Thanks - mine ERA is 098 - very early - so, no separate fuses?

No separate fuses. Your next step will involve either using a VOM (cheapy little volt ohm meter) or a 12 volt test light. Sound ok? And what was the result of checking your brake lights to see which bulbs work?

[patrickt]

Here, I did a five minute cut and paste on your car's wiring diagram so you can see what you are dealing with. Since your front flashers work, you know that your signal wand switch, and the flasher unit, are both probably working properly. Your brake lights and signal lights use the same filament. So, from that, you can surmise that:

1) If your brake lights are working normally, then you know the connections from the trailer relay to the rear bulbs are good, including the grounds.

2) If your brake lights are also misbehaving, then it could be either the trailer relay, or the connections between the relay and the bulbs, that includes the grounds.

You will need to test the voltage, using a VOM or test light, coming out of the trailer relay, on both the yellow and green wires. If those readings are good, then you will test the wires as they go in to the bulb fixture itself (note that it appears the wire colors change). If we have to, we'll also check the wires going in to the trailer relay and maybe use a 12v jumper wire to test the bulb circuit itself. The way you will check the wires is to carefully scrape a little bit of the insulation off of them, using a razor, so that you can see the copper conductor. This is really not hard at all.

If I had to guess, I think it's going to end up being either a bad trailer relay or a bad connection (that includes a ground).