Charging Issue 71 Inline 6

[circa73]

I've scoured the threads and not sure where to go next. My battery is not charging. Truck has been under construction for so long I'm not sure how long this has been going on.

Took the alternator to AutoZone for testing. It passed. Replaced the external regulator and it still isnt charging. I have an ammeter, but I am pretty sure it is fried (stuck in the middle)

I measured voltage at the battery while it was running, and revved it up through 2200 RPM and only got 11.7 volts.

I did some the tests in the C10 service manual. Plug position #4 to ground lit up the test light. Position #4 to F didn't do anything, and my test light isn't long enough to test position #4 to F on the alternator.

The wiring diagram isn't helping me understand the circuit from the firewall and back out. When I read the horn relay has something to do with operation, I wanted to pull my hair out.

Other disclosure: I installed a tach PWB on the dash cluster so I could mount a boost gauge in the vacant spot where a tach would have gone.

I'm thinking of taking the path of least resistance at this point (no pun intended) and going with a 1 wire alternator with internal regulator.

Is there something else I can check without 4' of test light wire?

Thanks!

[vince1]

Is the regulator case grounded to the case of the alternator?

If you change the alternator and want to keep the lamp indicator in the dash I think you need a 3 wire.

[circa73]

Yes, regulator and alternator are grounded together.

[circa73]

I'm reading about a brown wire that goes to the cluster that gives a resistance so the voltage regulator knows when it needs to charge the battery. Does anyone know if that is my ammeter and how do I test it?

[circa73]

Found some more pearls of wisdom in another link with VetteVet

http://67-72chevytrucks.com/vboard/s...nt#post6145480

This led me to check my 4a fuses and one may have been bad at the battery side. The connector rubber was hard as a rock so I ended up breaking the glass when separating the connection. I got some more 4a fuses and will be replacing them this morning. Will keep everyone updated.

********************************** UPDATE*************************************

Not charging after fuse replacement. Running at 2200 RPM I got 11.67 at the battery.