check the block to make sure its grounded to the body. there should be a strap from the body to the back of the block and the battery ground should be on the engine head bolt also on the core support in connection with a black wire.
68 400h.o 4spd all numbers matching
My gauges are really messin with me now. I thought I had it fixed. Battery neg post to heads, neg lead to the fender, cant seem to find a ground strap any place. I have been up underneath it looking. My gauges work fine until (1) I put a blinker on, then they "bob" with the blinker light, or (2) I turn my headlights on then the fuel gauge goes to zero, and temp rides a bit high, oil press barely reads.
