Electrical and AC questions
 

My son and I bought an 86 Silverado C10 and it's been mostly restored. I don't have a shop manual yet so I figured I'd ask here while I hunt a manual down.

The voltage at the battery is 16.6 volts. Clearly this is too high and will boil the battery away. I suspect the alternator is at fault and it has an internal regulator? Do I just hunt down a replacement alternator or can the alternator be rebuilt?

The A/C has no freon. We will do a pump down vacuum test to see if there are leaks but if that passes I see that there is a "replacement" or a
"compatible" refrigerant for R-12 called "Enviro safe" can it be used or do we just pony up and buy genuine R12 and plan on ultimately upgrading the system to a current R134A refrigerant?

r-12 can't legally be sold anymore so that option is out. i have not used enviro safe but have retrofitted with r134a. It will require a differenct charge amount and different system couplers. I want to say 10% more but goggle will have the answer. r134 requires a different system oil so if enviro safe uses the same as r12 and connects to the r12 fittings, go with that.

you can check out rebuild kits vs new alternator. pickn pull sells check alternators with a 1 year warranty. All depends on what you want to pay vs the amount of time you want to put into it.

16.6 volts.

Your engine to firewall ground strap is clean and tight?

Your Negative Cable is in good condition, and grounded to the block and frame?

General Information and Maintenance

click that link youll be able to find 1973-87(91) GM Pickup Manuals
and
Complete 73-87 Wiring Diagrams ( Haynes )