The gauge jumps from 10 - 13, not steady for long periods of time. All connections at cluster check out okay. Alt. has been replaced, grounds have been checked, 13.8v at battery. Connectors have been cleaned, new battery cables. Any ideas on how to keep my gauge at 13, or does it just go down when the battery is at full charge.

Thanks,
Eddie

 

is this at idle or always?

 

always. Some days it stays on 13v but other times it fluctuates from 10-13 don't know if it matters, it's a 89 rs Camaro 305 tbi

Eddie

 

My friends car (89 RS, 305tbi iroically) does the exact same too.

But its alot more heavy liek 10-16 volts. it fluctuates. and it really does, its not the gauge. cuz the lights dim and everything.

 

I may have found my problem. The printed circuits for the instrument panels (part #25081605) is partially corroded green. found the part at classic industries for 70.00, so I may try this and hope for the best.

Eddie