Hey that's great that the new parts are working out, your RPM guage gets it's signal from the alternator, check your wiring, plug that is into the alternator, it's connection is through the regulator (inside the alternator) could be regulator problem, or many other places. Somewhere to start.
Last edited by grancito; 08-15-2007 at 03:18 AM.
1995 6.5 turbo GMC K2500 extra cab 4x4 pickup, PMD under bumper, mechanical wastegate, 228,000 miles, rebuilt engine, 4.10 diff, 16 mpg
1994 6.5 turbo GMC K2500 4x4 suburban "F" VIN #9 resistor, PMD in the bumper, mechanical waste gate, 226,000 miles, Positrac 3.73 diff, 17 mpg highway.
1982 4x4 shortbed 6.2 Chev 260,000 miles untouched motor 17 MPG 4.27 diff. Best thing I ever owned, 21 years.