Hello oldsguy and labrats804 i have the tach on 6cyl and it does the same thing the needle don't move it just move to 2000rpm even when i raise the engine.and the voltmeter i have the red wire connected to the fuse box were the acc opening is at the fuse box under the dashboard,the orange wire to the contact that always have constant power under the dash,and the black wire connect to a piece of metal behind the radio that i scraped real clean.i hope i didn't waste my money on these gauges
