Alternator spikes

[Chiefdan]

Guys, I tried to put this on Electrical and no response so Moderator, move this wherever you see fit. Chief :Ok, this isn't for my Chevy C10 but this is the only automotive board I subscribe to so maybe you guys can help me. 1964 Nova Gasser, 383 stroker, 4 speed. I put a 1 wire chrome alternator in with battery in the trunk. 10 guage wire from alternator to cut-out switch in the trunk and then to the battery. The other night the voltmeter read all the way to the right (18+ volts). When I stopped the car it would not start because of blown 40 amp fuse in the wire from alternator to cut-out switch. New fuse and it started and ran normally with meter reading around 13.5 v. Am I looking at an alternator problem or possibly something else? Thanks for the help. Chief

[gmc684x4]

One wire alternators can be lots of trouble
some guys swear by them most hate them

Cs 130 /144 Alternators are way better then the farm tractor style 1 wire alternator they where originally developed for

10 gauge is good for 30 amps also you have a long run adding voltage drop which raises amperage 8 AWG or 6 AWG is what you will need to run to the trunk

I suspect small wire long run lots of voltage drop which in turn makes the current go up higher

[body bolt]

Originally Posted by Chiefdan

Guys, I tried to put this on Electrical and no response so Moderator, move this wherever you see fit. Chief :Ok, this isn't for my Chevy C10 but this is the only automotive board I subscribe to so maybe you guys can help me. 1964 Nova Gasser, 383 stroker, 4 speed. I put a 1 wire chrome alternator in with battery in the trunk. 10 guage wire from alternator to cut-out switch in the trunk and then to the battery. The other night the voltmeter read all the way to the right (18+ volts). When I stopped the car it would not start because of blown 40 amp fuse in the wire from alternator to cut-out switch. New fuse and it started and ran normally with meter reading around 13.5 v. Am I looking at an alternator problem or possibly something else? Thanks for the help. Chief

Is the voltmeter connected between the fuse and the alternator? That would explain the 18+ VDC 'spike' since there would be no load on the alternator.

[Steeveedee]

High voltage output means that the voltage regulator is not functioning properly. If it keeps it up, replace the voltage regulator.