My 93 sc300 headlights flash (go dim for a second) when brake pedal is pressed. I have changed the alternator, and the ground wire from the battery to the block. Also when at an Idle, with hvac fan on, turn signals make the fan power go down.

Any ideas?

Thanks for any help.

 

mine just loses a little intensity when i brake and when i release it, it just goes back to normal.

 

Does anybody know what causes this?

 

I put a net chasis ground from the negative post of the battery to the fender,, no more headlight dimming.