My experience with car mechanics is they are good with mechanical systems, but have little understanding of anything electrical, and even worse with electronics.
P.S. If you're doing a bit of wiring on the car, don't use those crimp on wire connectors. They'll work ok for a year or so, and then start behaving erratically, slowly getting worse and worse. This is because the crimp is simply not tight enough, and the mating surfaces start to corrode.
The best solution is to strip the wire ends, slip some heatshrink tubing over the wires, cut the plastic off the butt crimpon connector, crimp it on, solder the wires to it, move the shrink tube back over the joint and shrink it on.
This goes for any crimpon connector.
Also, don't use the auto wire you get at your local auto parts store for anything in the engine compartment. It won't last in the heat. You gotta get heat resistant wiring.
P.S. If you're doing a bit of wiring on the car, don't use those crimp on wire connectors. They'll work ok for a year or so, and then start behaving erratically, slowly getting worse and worse. This is because the crimp is simply not tight enough, and the mating surfaces start to corrode.
The best solution is to strip the wire ends, slip some heatshrink tubing over the wires, cut the plastic off the butt crimpon connector, crimp it on, solder the wires to it, move the shrink tube back over the joint and shrink it on.
This goes for any crimpon connector.
Also, don't use the auto wire you get at your local auto parts store for anything in the engine compartment. It won't last in the heat. You gotta get heat resistant wiring.