im the owner of a 77 pickup
20r
and the CHG light came on.
I have put in a newer battery and switched the alt, the light is still on do I need to reset something, or is my batery just not charged?

 

my 81 with a 22r has the same problem. it might just be a loose wire like mine

 

check the batt voltage then start the truck and check it again .there should be an increase. you will need a good volt/ohm meter. if there is not a change it might be the voltage regulator or bad connection. also check the fuses.

 

Hit the PS side dash. If it goes off your charge light relay is bad. Thats what happened to my 82, but toyota wanted like 80 bucks for the relay. I just unplugged it

 

or find a aftermarket gauge pod with a volt meter thats what i did

 

Which fuses should I be looking at? the ones in the dash, or are there other ones?

also where is the voltage reg?

My truck is still dying just in the middle of the road.. kind of sucks..

any other advice?

 

check the fuses.. i had an 81 that the charge light would come on until i ran the RPMs up to about 5k.. then it would go off. i found that there is a fuse labeled ENG that had blown..

 

Where is the voltage regulator?
and how can I tell if its not functioning properly?

 

Voltage regulator is on the driver fenderwell under the hood.

 

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I put a milti meter on the two contact's and got less than one volt.. is that right?

 

Get a chiltons or haynes manual, they both have the testing procedure.

 

autozone has free online manuals .you will have to register and do a little searching ,they like to push the pay site but the free site is there. also most local libraries has free online data bases, you just have to get a library card.