Short circuit locator
Posted: August 11, 2010, 12:44 am
Here's a trick I picked up from Fred Martin for tracking down short circuits single handed.
A while back all the rear lights went out on my 66 with a blown fuse. As soon as replaced the fuse blew again. I went about tracing wires looking for pinches or bare spots. Findiing none, began disconnecting wiring harness one run at a time to isolate the problem stretch -- no luck.
At that point I had a small mountain of blown fuses and needed a better way. Got a 12V buzzer at Radio Shack (I think it was about 80 cents) and stuck alligator clips on each lead. Used the clips to jump the failing circuit at the fuse block activating the buzzer. Then started disconnecting and reconnecting wiring connections until I disconnected one that stopped the buzzer - guilty run isolated.
In this case it was a short inside the brake light pressure switch on the master cylinder -- explaining why it couldnt be spotted with inspection.
Hoped to upload a pic, but don't see to have that option here.
A while back all the rear lights went out on my 66 with a blown fuse. As soon as replaced the fuse blew again. I went about tracing wires looking for pinches or bare spots. Findiing none, began disconnecting wiring harness one run at a time to isolate the problem stretch -- no luck.
At that point I had a small mountain of blown fuses and needed a better way. Got a 12V buzzer at Radio Shack (I think it was about 80 cents) and stuck alligator clips on each lead. Used the clips to jump the failing circuit at the fuse block activating the buzzer. Then started disconnecting and reconnecting wiring connections until I disconnected one that stopped the buzzer - guilty run isolated.
In this case it was a short inside the brake light pressure switch on the master cylinder -- explaining why it couldnt be spotted with inspection.
Hoped to upload a pic, but don't see to have that option here.