Weird electrical issue

this is my first jeep (1998 XJ 4.0L), so ill try and explain it as best as possible:

When i have my headlights turned off, and i depress my brake pedal, the lights that display my milagae, and the lights on the radio turn off completly. Then when i release my foot from the brake pedal, all the displays come back on.

It doesnt effect how the radio functions at all, just the displays turn off.


But when i have my headlights on, it doesnt do it anymore...


like i said, this is my first jeep, i bought it a few weeks ago, and it came this problem...

any suggestions are appreciated!

thanks,

-Matt

Possibly a bad ground at one or both tail/brake light assys. Goofed up bulb(s) out back. Do your park lights in the front glow or turn on while on the brakes?

X2 on the bad ground

short in the brake switch probably

I don't think it would be in the brake switch. What I think is going on is the park light circuit is getting juice from the brake light circuit, causing the radio and odo lights to dim out the same as if the pk lites were turned on at max dash dim. If there is no ground at the tail/brake lights then the brake lights will try to ground through the tails/pks, putting volts in the pk circuit. They would actually be grounding through the front pk lights. This is assuming the radio and odo are digital

Of course I've been wrong before but that would be where I'd look first.

thanks for the replys.

ill check out the ground for the brake lights tomorrow morning.

-Matt

alright i looked for the brake ground, and couldnt find it...i searched the interent, and looked in the haynes book...

could someone tell me where the ground is?

thankss

-Matt