Taillights and turn signals not working

Hi,

If I understand, you used the wiring harness from the Pontiac and modified it to work on the cavalier. Is that correct?

Please understand that not being there is going to be difficult for me because I don't see what has actually been done, but I am going to try to help the best I can.

Now, if the fuses and switches are good, what really needs to be done is to see where power is lost. For example, is there power to the brake light switch? Also, is there power to the headlamps or to the new multi-function switch?

I am going to provide the wiring schematics for the 97 Cavalier for your reference. The first two pics are for the exterior lighting (not headlamps). I highlighted fuses. Make sure not only the fuses are good but make sure they have power to them.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Also, check for power to the logic module, the brake light switch, and the multi-function switch.

Next, I attached the schematic for the headlamps. Make sure both fuses are good and there is power to the switch.

I had to cut the pics in two to make them readable. I did overlap them so you could follow them.

Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-wiring

Let me know what you find or if you have other questions.

Take care,
Joe

Hi,

Is there power at the fuse (stop/hazard)? If there is no power at the switch, backtrack to the fuse. See pic 1. If there is power there and the fuse is good, we have an open circuit between the two points.

Let me know. Hang in there. Wiring can be a nightmare. LOL

Joe

Hi,

If there is no power to the fuse, we need to backtrack to see where it's lost. Ok, hang in there. If there is no power, that is why they aren't working. You confirmed there is no power to the fuse I showed above. Now, we go back further to the fuse box under the hood. If you look at the attached pic, it shows where the power comes from. Check that fuse next. If it has power, there is a break between the two. If there is no power, then we have an issue with the fuse box under the hood.

Let me know what you find. Don't worry, we'll get it figured out together.

Take care and I hope you have a good Christmas.
Joe

If there is power at the fuse block, there has to be a broken wire between the fuse and the switch. Are you able to trace the wiring to check for an open circuit (broken wire)?

Joe

Power comes from the battery to battery fuse 2 (40 amp) in the underhood fuse box. From there it is distributed to stop/hazard fuse in the vehicle. From that point, constant power goes to the brake light switch. So, if there isn't power at the switch, we have to work backwards to see where it's lost. If there is no power at the stop/haz fuse, then check the battery fuse #2 in the underhood fuse box. If there is power in an out from that fuse, there has to be a broken wire between the two or at least there has to be something preventing power from getting there. If there is no power under the hood battery fuses, chances are the fuse box is bad. I added a pic below and the arrows show the power flow direction. We need to find where (in those wires) there is an open circuit.

Let me know. Don't worry, we'll figure it out together.

Take care and I hope you had a good Christmas.

I will watch for your reply. Also, I'm not sure what you are referring to when you say brake relay. Let me know.

Joe