Alternator Upgrade

[JTs70C10]

My first posting for upgrading my 1970 C10's alternator. My original alternator with the external regulator wasn't charging anymore so I upgraded to a one wire chrome one from Powermaster and a Summit Racing chrome bracket. Pretty straight forward install, only hiccup was finding the right size belt. Had to go from at 53.5 to a 54.5 inch.

If anyone wants any additional pics or questions just ask.

[engineer_gregh]

Did you modify your existing wiring other than just running a single wire from the alternator to the hot battery post? Seems like I've read that with one wire alternators that there is a drain on the battery after engine shut down without some wiring modifications. What size wire did you use? Did you use a volt meter before and after the swap to see the difference? I need to upgrade mine, sorry for hammering you with questions.

[JTs70C10]

The PO left me a rats nest of wiring gremlins so I pulled it all out and installed a Painless #10206 kit in it. It came with 8 and 10 gauge alternator wiring regular and a high current kit for over 65 Amp alts. It also comes with a huge 70 A maxi-fuse for protection. I have an Autometer volt meter in the dash, not a light so that was not an issue.
The original alternator was putting out 13.5 VDC (using handheld voltmeter), but when I turned the lights on I could watch the numbers start dropping down to around 10.9 VDC. It couldn't handle the load. Autozoneout said it was good?!?!?! The new alternator came with written test results. It is putting out 14.4 VDC and only drops a tenth or two with the lights on.
As for the battery drain while off, I have not verified or checked this but I will. I'll see what the voltage does and see if I have a current drain and I'll post what I find.

[engineer_gregh]

Thanks JT. Great write up.