Troubleshooting Truck electrical
Monday night I went to start the truck, and was greeted with a run down battery. Not enough juice left to crank it fast enough to start.
Checked out electrical system, and figured out there was no output from alternator. Bought a new alternator, but before I changed out the whole thing I decided to try just the voltage reg. And brushes from the rebuilt alternator.
Sure enough it works now, battery charges, back to normal
But: charge voltage is 13 at idle and 13.5 with engine revved up high. It's within spec but seems to me kind of low, and I am at a loss as to why. I would much prefer to see 13.8 - 14.5 with engine revving.
I am thinking for next steps: check battery terminal of alternator with scope to verify if I have any bad rectifiers
Check charge current at idle to verify if I have any parasitic loads
Unfortunately regulators for this alternator are pricey so I can't easily swap in a new one just for the sake of testing.
Truck is an 86 Toyota pickup, with 2.4 Diesel engine.
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