Dixie Life
Senior Member
OK, I give up. I can't find the problem with my OP gauges.* Both guages peg high when powered up.* With power off they read about 40; (0-80 guages). When eng. is rev'd to 1600 rpms the needle will drop from pegged to about 80 and when lowered to idle back to pegged again. I guessed both guages can't be bad so, I changed the sending unit. No change. I changed the lower guage with a new one; no change.* Took the orig. lower*guage an swapped it with the upper unit; no change.* The only thing I haven't done was change all the wiring. The guages are orig. GM type on a Lehman Ford 120 system.* What am I over looking?