I would bet on a short to ground on the lights too.

If you keep turning the dimmer pot up to pop the breaker,
you will eventually cause the dimmer pot to fail which will
be more expensive than you would guess!!

These cirucits are notoriously poorly protected for over current
conditons.

Bill Hale BPPP instructor

On Jul 8, 6:43*pm, Blanche wrote:
I did have a bad transistor that controls various lights in the
cherokee. I think I paid $4.00 for the transistor, and $65 in labor.
But, I also bought a complete set of 4 extra transistors because
I know they'll die - afterall, they were original 1969 equipment.
I'm astonished they lasted this long.