Lost all rear brake/running lights?

MINNIE1001

MEMBER
1999 CHEVROLET BLAZER
4.3L
V6
4WD
AUTOMATIC
248,000 MILES

Lost all rear brake/running lights. Wrenched for 11 years. Upper top brake light works. Should rule out stop switch. Blowing the 10 amp fuse under the hood r/l park. More fun, fighting the blazer mysterious voltage drop. New battery, alternator, mod done for alternator per service bulletin. Tore the trailer hitch wiring apart to make sure nothing touching. Don't know if the two are related, all new bulbs. License plate lights work, cut that green connector out years ago, reverse lights work, same harness as the stop/turn/running.

Sunday, July 20th, 2025 AT 6:33 PM

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
54,137 POSTS

It seems you have a few problems; the brake lights are not working due to a bad turn signal switch. Also, the "r/l park fuse" can you please recheck that I don't see it in the rear light wiring diagrams. Here is the wiring for the taillights so you can see how the system works. Also, I included a guide to go over as well?

https://www.2carpros.com/articles/no-tail-lights-exterior-running-lights-tail-lights-out

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