Use For the Stock Amp Guage

[Don Quixote]

The new wiring kit I installed in my 72 last year didn't allow for wiring up the stock amp guage and for good reason with most running 100 amp alternators these days.

I did however, find a use for an otherwise dead guage.

I pull a lot of trailers and most of them have electric brakes that run off of a 40 amp circuit breaker. Since the guage will handle up to 60 amps, I found that I can run the brake line off of my trailer brake module through the guage and block off that portion of the printed circuit. I can now get a basic assessment of what my trailer brake is doing much like the air brake pressure guage in a semi-truck and not worry about catching my dash on fire.

As a last resort backup, I have a brake light cutoff switch on the dash, normally so I can use my hazards while I back up and bypass the trailer brake to do so. If I were to ever have a problem I can throw the switch and power will be cut to that circuit as well.

Be sure you use the exact same guage wire (usually 12awg) to make this circuit and when you test it, if it reads a discharge, just reverse the wires and be sure not to peg the thumb switch as it will peg the guage. This is useful for things such as brake leveling and power adjustments.