A Hot Rod Wires harness is not made for an ammeter. To use it you will need to run a supply line to it and back. If you hooked the voltmeter wire to it, it is not going to read amps.
And by the way, I have never heard of a fire caused by an ammeter. Millions of vehicles ran millions of miles with them. I'm running a stock one on my Suburban with an alternator and an after market one on my yard dog with alternator.
