Either meter (volt or ammeter) is a posible fire hazard if it is not wired properly. With alternators under 70 amps output I prefer to have both a volt meter and an ammeter. Either gauge alone only tells you half the story about your cars state of charge. You can be charging at 15 volts and putting out 60 amps if your battery is internally shorted or charging at 12.5 volts and 60 amps if your battery is close to dead. Having only one gauge you can't diagnose the problem - or even know you have a problem. When an alternator puts out more than 70 amps you simply can't run big enough wires to and from it to make use of an ammeter. That only leaves the volt meter untill it gets funny and starts to act up. Then you have to put the shunt type ammeter on it and test the output in amps and volts.
Well I can't run one anyways because I'm over 70 amps. Still, I had no issue telling that there was a problem with my charging system when the problem initially appeared. The amp gauge is an unnecessary risk to me. Maybe if you put it on a fuse or circuit breaker.
And now, I present you more charging issues. Now, it charges fine at low engine speeds, say, below 2,000 rpm. You can drive around town forever with everything in the car going full blast, no problems. Get on the interstate, and everything starts going down hill. It'll get dead to the point that the car starts spitting and almost quits running. Put it in neutral for a second and let the RPM's drop back down, everything comes back to life. I have it wired exactly like every thing I see on line says to wire it. The main charging wire is a brand new 6 gauge cable going directly to the "hot" side of the starter solenoid, terminal 1 goes to the ALT light in the dash, terminal 2 has constant 12V like it's supposed to. When you turn the key to the on position, the ALT light comes on like it should. Start the car, the ALT light goes off like it should. It never comes back on while the car is running, even when it's not charging. I'm about to start pulling my hair out.
I think the fan belt might have loosened up.Check your voltmeter at idle then slowly rev the engine and see if the voltage goes up and then starts to go back down the higher it revs,usually a loose belt.
I agree. Jamie, see if you can turn the fan on the alternator by hand with the belt still on. MAKE SURE ENGINE IS OFF WHEN PREFORMING THIS OPERATION!!! Had to throw that little disclaimer in as per my lawyers instructions! Anyway, if you can turn it by hand, the belt is not tight enough.
If it's not the belt it could be a short, i have a 63 chevy that had a short so bad that it would kill the truck.
I have a very similar problem. Does anybody have a real schematic for the charging system? Also, where can I get a new resistance wire and fusible link for a V8 system having a Voltmeter without the Alternator indicator light?
Here is the main chassis diagram: It is for the 73 but the charging and starting wiring doesn't change.
my car had the same problem and i found a broke wire in the harness going to the voltage regulator. replaced wire and have not had a problem since! good luck!
Thanks. I've just made a new harness and will try it for function. With all the help I've had with different circuits, I been able to get to the component level. With any luck it'll do (I'll post results when I finally get to it). Bob
I installed the new harness and connected everything properly. All systems GO !!!!!!! It seems the guy who wired the car before I bought it damaged the OEM harness and connected the regulator in the manner needed for an idiot light. Then he installed a Voltmeter and removed the idiot light. Consequently, I don't think the charging circuit was working properly and eventually burned out the regulator, blew the diodes in the alternator and burned up the terminal for the lead from the Alternator to the battery. To top it all off, which is probably the biggest reason the charging system failed, the regulator was not grounded properly. The new Alternator, regulator, harness AND ALL THE HELP I GOT FROM YOU GUYS got me out of trouble. Thanks again to those who made suggestions.
I never did figure out what was causing these problems. I ended up just chucking the stock stuff in the trash and put on a 90 amp Chevy 10SI alternator. It's been on there for about 65,000 miles now, no problems.
