I’ve been troubleshooting an issue where I have no taillights, no parking lights, and no dash lights. That lead me to the TNS relay. I swapped the 30 year old relay with a brand new one from Atkins, replaced the TAIL fuse with a new one, and I still have the issue.

Back-probing the relay shows that I’m getting 12V from the BTN/TAIL circuit on the W/G wires.

One interesting thing: without the headlight switch on I’m getting a constant 12V at the GY wires

Second interesting thing: I am getting no voltage at the R/B wire.

Brand new relay is bad? Something with the combination switch? I’m admittedly not the best with wiring diagrams, but it seems the TNS relay should be sending power to the R/B wire if I’m getting voltage through the coil.

This is low on my list of things to fix on the car, but it is very annoying. Thanks for any help!

 

Jack up the car, remove the driver's side tire, and FULLY get in the wheel well and check to see if the tire has rubbed through the fender liner and into the harness. Very common problem and it many times damages the wiring for the lighting.

Don't say "nah, it's fine" or just half look in there, TAKE THE WHEEL OFF AND LOOK. If you find nothing, GOOD, but that's a very common issue and the first place I would check. May even be worth pulling the fender liner and make sure it isn't damaged then a new liner was put on or something.

Dale

 

Great time to do that, it’s already in that state. I’ll take a look and report.

 

Actually looks pretty good. There’s one spot where it rubbed through the loom, but the exposed wires are intact, no breaks in the insulation.

Any idea why I’m not getting power from the relay?

 

I’m going to test the new TNS relay today, but from my understanding of the diagram I likely have another issue somewhere as well.

I’m not sure why the signal from the combination switch at the TNS relay has 12V with IGN to ON without the switch being activated.

 

Do you see taillights coming on if you jump W/G and R/B with a piece of wire (while the relay is removed) ?

 

Yep, just checked it. When jumping those wires, taillights, side markers, and parking lights come on.

Haven’t had a chance to test the relay yet, I’ve been out of town.

 

Update:

I ended up swapping in another TNS relay and all the lights work. However, the lights are always on when the car is running. Ze switch, it does nossing… so I guess my next step is to diagnose the combination switch. At least it’s driveable.