Lighting dims question

[Patrick L.]

Originally Posted by Tom Wesenberg

"Turn on the lights, but as soon as I hit the brakes, lights dim considerably. Also, with lights on (no brake lights yet), horn just says 'eeeeer', although I have a great horn without the lights on."


Sure sounds like a short in the brake switch, wire, or brake light socket to me.
What does the ammeter read when you step on the brake?

Yep, agreed. Others think the same. I'm wondering if we will ever know.

[alexiskai]

Originally Posted by Patrick L.

Yep, agreed. Others think the same. I'm wondering if we will ever know.

Everyone remember that the OP has a whole life, job, takes vacations, gets sick, and has to do the actual work that we are merely typing about. Give him more than 5 days to get back to us.

[Penthode]

Originally Posted by Patrick L.

Yep, agreed. Others think the same. I'm wondering if we will ever know.

I strongly disagree. Without touching the brakes and switching on the headlamps only, the horn diminishes.

It is the wiring. Think about Ohm's Law. It is the DC resistance from the battery to the junction at the head lamp switch. Did you read my detailed post?

As was pointed out by Badpuppy, it could simply be a high resistance between the positive battery post and ground.

If it was a brake switch short, the ammeter would peg and you would get a bad smell...