Brake makes radio stop

[dparish]

77 CJ-7

When I step on the brake the radio stops working. When I keep the foot on the brake the radio comes back on so the actual cut off time is only a second or two. Lift the pedal, then press it again, the radio drops out.

Seems like a power draw issue related to the brake lights. Other electrical changes (blinkers, headlights, etc) don't cause the problem. The horn does cause it but it's wired odd so I'm not sure a great diagnostic aid. This of course used to work just fine so I'm not sure what shook loose or changed to cause the issue.

I hooked up a multimeter and the voltage draw seems pretty constant and the amp draw doesn't seem to change. I admit to not being an multimeter expert so I easily could have missed something.

Any ideas on what to look for?

 

[tp=n=yj]

check the ground strap on back of motor to body witch grounds the body.

 

[LGR]

I had kinda the same problem on my old 83 volvo. When I stepped on the brakes the radio would come on, lift my foot off and the radio goes out. Had to ride the brake to listen to the radio. I just ran a new power wire from another spot in the fuse panel and fixed my problem.

 

[black87yj]

77 CJ-7

When I step on the brake the radio stops working. When I keep the foot on the brake the radio comes back on so the actual cut off time is only a second or two. Lift the pedal, then press it again, the radio drops out.

Seems like a power draw issue related to the brake lights. Other electrical changes (blinkers, headlights, etc) don't cause the problem. The horn does cause it but it's wired odd so I'm not sure a great diagnostic aid. This of course used to work just fine so I'm not sure what shook loose or changed to cause the issue.

I hooked up a multimeter and the voltage draw seems pretty constant and the amp draw doesn't seem to change. I admit to not being an multimeter expert so I easily could have missed something.

Any ideas on what to look for?

did you crall up under the dash and look behind the brake pedal and fuse box ? something pinching the radio wire and grounding it out ? or pull the radio and look at the connections for frey or pinches ...just thinking out loud.

 

[getsnakebit]

check the ground strap on back of motor to body witch grounds the body.

My TJ did same thing, changed the ground from battery to vehicle. Fixed it for less then $10 also thought it could have been too large of a load on the battery. Does the voltage drop when brakes are applied?