Diagnosing charging system

[SolidLifters]

I can't recall how to troubleshoot the charging system on a '67, but mine is not showing charge on the guage in the dash. I have about 13V at the battery (car stays on Battery Tender). I have about the same voltage at the 10 guage red wire terminal at the back of the alternator. Don't know what to read next, or what the readings should be.

 

[jackfit]

Hi, When I hooked up my engine harness for the first time in a few years, I am doing a complete restoration, I was not getting any plus movement from my gauge. It would show discharge with lights on etc. It turned out to be one of the small wires was broken just off the plug that plugs into the voltage regulator. Check the wires at that point. I fixed the blue wire (I think) and the guage started to show charging right away. John Z or someone else on this site will know other methods, but check the wires first.

Jack

 

[JohnZ]

A fully-charged battery should show 12.4-12.6 volts across the terminals (engine off). With the engine running at 1500 rpm, the same check should show 13.8-14.5 volts; if you still show 12.4-12.6 volts with the engine running, it isn't charging. Make sure the black ground wire in the harness to the base of the voltage regulator is connected (under the same screw that attaches the radio capacitor to the regulator), and make sure the other black harness ground wire is on the ground stud on the back of the alternator. If the regulator isn't grounded to the alternator, it won't charge.

If voltage check across the battery terminals shows it's charging, but the battery meter needle doesn't move, it's either a wiring issue for the sense wires, or the meter. With the engine off, pull the connector off the back of the battery meter and check voltage to ground at each terminal in the connector; both should show battery voltage. If one (or both) doesn't, it's a wiring issue, probably in the multiple connector on the engine side of the fuse block.