I was wondering if there is a way to test a hood tach. I ave a 69 firebird with a hood tach. Im going to assume it is an aftermarket hood tach, as it was on the car when I bought it. Aside from the two brown wires and two black wires that are powering the two light bulbs, there are two black wires and a single brown wire coming from inside that housing. all of the wires went to a male plastic plug that plugs into the harness from the distributor, a ground, and and what looks like another relay. unfortunately all the wires from the tach itself broke off of the plastic plug that holds the wire connectors, so I don't know where all the wires go. The plug holds three wire connectors, but there are 7 wires. I'm assuming the brown wires from the two lights would go together and the black wires from the two lights would go together, but then where would they go in the plastic plug? that would also leave me with the two black wires and a single brown wire coming from the tach mechanism.
Also, after attempting to wire it the way I thought I can get the lights to work, but the tach doesn't work. The tach was working before I had the wires break off, but I would like to test the tach to make sure I'm not going crazy. Any help or suggestions would be greatly appreciated.
had a similar issue with my hood tach on my 69 400. the tach was wired to the ignition. the tach lights were always on whe the car is running. i changed and wired to the lights, no tach unless lights were on. Duh. I wired back to ignition and put new LED bulbs in the tach. it works fine that way for me. Not sure if that helps