no rear lights

[Modular97LSC]

so I replaced my neon ballast yesterday on my 97 LSC and I noticed that non of my rear lights work, not even the license plate lights work only the front ones and thats when I hit the switch to turn on the lights. So I hit the switch and only my front lights come on and nothing on the back, but once I step on the brakes my lights do flash and my turn signals work. I already checked the fuses and I checked the harness thats in the trunk by the drivers side hinge it looks fine. What else do you guys think it might be?

 

[04_Sport_LS]

So if the lights were working before I changed the ballast... I'd be asking myself what I did.

 

[Modular97LSC]

I dont think they were working bc ive never driven this car at night. Ive only had it 2 weeks.

 

[04_Sport_LS]

So besides the license plate light... it's only the tail lights that aren't working... correct? Are you 100% sure the bulbs are good?

If the bulbs are good...

Use a volt/ohm meter or a self powered test light to check for continuity between the light sockets and the harness plug.

If that checks out... then you'll have to check for power to the harness at the left trunk hinge.

If no power at the hinge harness... you'll have to trace it back up to the front of the car... then check for continuity again.

Chiltons and Haynes repair manuals usually have wiring diagrams in the back to help figure out what is what... and what goes where.

Could be as simple as part of the headlight switch or a relay going bad... but do you wanna waste the money to find out those parts don't fix the problem?

 

[Modular97LSC]

ok guys so the issue was a blown fuse. Its fuse number 31. It pops when you reconnect a bad ballast thats been disconnected bc it shorted out. So basically what happened was that the previous owner disconnected the ballast bc when the ballast shorted out they couldnt get the car out of Park so they disconnected it replaced the fuse that pops but also forgot to recheck other fuses like fuse number 31 that had also popped along with the other fuse. Its a bit confusing but thats basically it. And on top of that they were driving around with no rear lights b/c fuse 31 is for the running lights.

 

[kenjmoser]

I just had the same issue - no brake or running lights and wouldn't move out of Park. Most blogs talk about fuse one being the culprit, but I found that 31 was out which gave me back running lights. But then so was 32 which controls Brake On/Off Switch & Brake Pressure Switch. With the ballast disconnected and these fuses replaced everything is functioning fine again on my 97 LSC.