Dome light on when depressing brake pedal
 

I have had this problem several other times but it comes and goes. Should I be looking for a ground issue?

Do you ever think it was a good idea to brake at the time?

Sorry, couldn't resist...and yes, bad ground gremlin

brake lights dome light and trunk light I think are all on the same curcuit

replace/check all bulbs with quality replacements
and
clean grounds....

one of the bulbs seems to be looking for a ground thru the domelight

Scott

thanks guys. I figured that was the case. Have had some issues with the brake lights.

Check Fuses
 

If this is on the 79, check your fuses.

Complicated but has to do with dome and courtesy lights sharing the same grounds.

Dome is hot all the time. Ground turns it on. Blown stop/courtesy fuse lets the dome light find ground by feeding back through courtesy lights to the stop lights. Not enough juice left for the stop lights to come on.

Weird stuff
Clay

Don't know if a '79 has the old glass fuses. Have had issue's like the OP has and found the fuses looked good but was not making good contact on the ends. Back feeding some strange issues.

This ^^^ regardless of year.

Yea, my 79 has the glass fuses. Some of them have been in place for who knows how many years. Might pull all of them and install new ones. Probably some corrosion on the contacts.

Restarting this thread. Never found the problem but now there is a new twist. When the doors are closed the dome light will come on if I depress the brake pedal which was the original problem. If I open either door the courtesy lights come on as they should but the dome light does not come on. And if I depress the brake pedal the dome light still does not come on. I am stumped as I have not found a grounding issue or anything else. Feel free to weight in!

The new twist is still describing what happens when the car has a blown/bad stop light/dome light fuse.

And that fuse will show power on both ends, when checked with a testlight, even though the fuse is bad.

I've had fuses "look good" but the strip inside not be making contact with the end cap. In the case of dome/stop it will still show power, on both ends, when tested in the car.

Hitting the brakes, with doors closed, creates a ground path for courtesy lights and makes the dome light glow but not enough power to make the brake lights come on.

Doors open the courtesy lights use up the power so the dome light doesn't glow when you hit the brakes.

Clay

Thanks for the help. I will plan to replace the fuses regardless of how they look or test.
.

Re-check the bulbs in the rear. If you have a single contact bulb in a two contact spot it will do that. Or vise versa.

Finally got it. I replaced the hazard flasher and the stop light/hazard fuse. All the gremlins went away. Woo Hoo. Every thing is back to normal. Thanks again for all the help.