No Brake Lights and a Valuable Lesson Learned

[71newport]

Several years ago the dome light on my '71 Newport quit working. I never drive it at night so I just never got around to replacing the bulb. I forgot about it. Last summer I noticed my brake lights quit working. So, I replaced the stoplight switch- very long and unpleasant job. Still not working. It was demoralizing and all winter I have been dreading doing an electrical troubleshoot. Then I randomly saw a post on another Mopar site where a guy's brake lights quit working on his A-body. Someone suggested checking the fuse. Fuse? I never even considered checking the fuse. In my 40 years of tinkering with Mopars I've never EVER had a fuse burn out (Ironically I always carried spare fuses in the glovebox of all my Mopars just in case). So.....I glanced at the service manual and, unbelievably, there is a dedicated fuse for........the dome light and brake lights! Popped that sucker out and sure enough- it was blown. Two problems solved in 30 seconds.

Lesson learned. ALWAYS check the fuse.

 

[Lefty71]

Good story..... back in the day the saying "Is the gas on, dummy?" had real meaning to motorcycle riders lol.

 

[stain]

The real question is, why is the fuse blown? Something made that fuse pop.

 

[Big_John]

The real question is, why is the fuse blown? Something made that fuse pop.

That's true, however automotive fuses will degrade over time due to vibration and other factors. They can degrade and simply fail or degrade just enough to fail with a lesser load. Some fuses are just bad quality to begin with.

Sometimes you just have to replace the fuse and figure it out from there.

 

[edbods]

Reminds me of a few problems I've tried to fix on computers. Did the complicated fixes first before trying a restart...and the restart fixed it, of course.

9 times out of 10 it works...it's only that 10th time that everyone remembers.

 

[57fury440]

My '57 does not have a fuse box. It uses circuit breakers. What Big_John said, fuses can go bad over time. It is an easy thing to do to check them first. Years ago, I purchased a Barracuda with a friend. We did some work on it, got it running and sold it. The guy we got it from said it had major electrical problems. the headlights worked but everything else was dead. Sure enough, there were no fuses in the box. We replaced them and everything worked. Always look at the obvious stuff first.

 

[fury fan]

Years ago the power locks stopped working on the 80 Diplomat.
I didn't bother with it as it wasn't much of an inconvenience.
Months went by.

The next time I hooked the little trailer to the car, the trailer lights weren't working.
I noticed that the wiring harness to the trailer plug had gotten pinched under a bolt in the hitch.
I fixed that and the lights were fine again. And the power locks were working again.

I had been driving around with no brake lights because a critical safety function was on the same fuse as a convenience function.
Terrible circuitry design. How that passed engineering FMEA (failure mode effects analysis) I will never know.