No taillights/brake lights
05-23-2019, 08:09 AM
#1
No taillights/brake lights So I’m working on diagnosing a taillight issue I’m having. I have working headlights, but my dash lights, brake lights, taillights, hazards, and fog lights don’t work. My turn signals still work. The alarm circuit does work—all the lights come on when the alarm goes off. All evidence points towards the switch being bad, but I’ve already replaced the switch twice, one with a part I ordered off eBay, and one with a switch I recovered from the salvage yard. All three switches (original included) have the same result. It looks like someone rewired the switch before, so I’m thinking it might be the connector. Any advice would be great.
05-23-2019, 08:43 AM
#2
TECH Resident
Those alarm systems (in my opinion) cause more trouble than they are worth.. I would start there as the installer doesn't make very good connections that will cause you to loose your hair trying to trouble shoot. I would start by checking and cleaning ALL the grounds. Good Luck
05-23-2019, 12:21 PM
#3
That would depend on whether it's a factory alarm system or not. The factory system can't be removed as it's part of the BCM.
The FIRST thing to do is check the TAIL LPS fuse (for the dash, fog lights, and tail lights) and the STOP/HAZARD fuse (for brake lights and hazard flashers). The fact that the lights work when arming/disarming the alarm leads to that conclusion because the factory alarm powers those lights independent of the TAIL LPS fuse. Never check a fuse by just visual inspection (especially a 20-year-old one) because it can look fine but still be blown. Either test with a fuse tester or multimeter or replace with a known good fuse.
If you replace the fuse and it blows right away, THEN you can start looking at the wiring at the headlight switch.
The FIRST thing to do is check the TAIL LPS fuse (for the dash, fog lights, and tail lights) and the STOP/HAZARD fuse (for brake lights and hazard flashers). The fact that the lights work when arming/disarming the alarm leads to that conclusion because the factory alarm powers those lights independent of the TAIL LPS fuse. Never check a fuse by just visual inspection (especially a 20-year-old one) because it can look fine but still be blown. Either test with a fuse tester or multimeter or replace with a known good fuse.
If you replace the fuse and it blows right away, THEN you can start looking at the wiring at the headlight switch.
05-23-2019, 03:09 PM
#4
Already checked the fuses (that’s was the first thing I did). Fuse 1, the taillight/brake fuse, was melted but not broken—someone put a 30A in the 20A spot. Inside the fuse box looks a little melty, so I’m going to check for continuity and resistance in the fuse box. I put the proper fuse in and lights still didn’t work. It has the factory alarm system, nothing aftermarket on it. Fuse 5 was fine. I noticed a burned wire coming off the switch, but no change after I fixed that. It looks like someone had already messed with the wires on the switch.
05-26-2019, 12:03 PM
#5
TECH Resident
Sounds like something went wrong on the fuse block and instead of actually fixing the problem someone just ran bigger fuses and wiring which just caused even more things to melt. Lucky it didn't catch fire.
If you have burnt wires and melted plastic you need to find out where the excess amps are coming from that are overloading the circuit. It could be a pinched wire or someone spliced the wrong thing installing lights or a stereo. If you don't fix the original problem you'll never get things working properly.
If you have burnt wires and melted plastic you need to find out where the excess amps are coming from that are overloading the circuit. It could be a pinched wire or someone spliced the wrong thing installing lights or a stereo. If you don't fix the original problem you'll never get things working properly.
05-26-2019, 03:49 PM
#6
I found the problem. It was rewired, but it was done relatively correctly. What happened Was the power wire to fuse 5 (which also provides power to fuse 1) had a splice in it, and the splice was loose (in fact it fell apart just by touching it). Respliced the wire, secured everything, wrapped it in electrical tape and everything works perfectly!