'71 Pig wiring diagram interpretation

[brider]

Can someone please explain via the factory '71 Pig wiring diagram just HOW/WHERE the battery gets charged from the alternator? I've studied it, and although I don't have it in front of me, I don't remember a charging path that doesn't go thru the fuse panel; seems kinda strange to me.

I will be intalling my new GM 94-amp alt soon, and want to do it using the MadElectric.com remote-voltage-sensing feature (found in the search function here at MUD).

But first, I need to understand my Pig's charging system so I can reconcile it with the GM system

 

[brider]

OK, so you answered 1 question, but without my wiring diagram, how does that charge get back to the battery?

Question #2: What circuit supplies power to the fuses?

 

[inkpot]

Howdy! I'm pretty sure that's how my 76 is set up. Of course it is not OEM. I am running a Delco Remy alternator with the "one wire setup", and that one wire comes out and T's off, one side to the fuseable link to charge the battery, and one side to run the truck. John

 

[cruiserbrett]

71's dont have an ammeter. So, what you are looking for is a black with red stripe-this powers the fuse panel-this would be a good pick for the voltage sensing wire. that wire is crimp spliced to the white 10 ga wire that goes from the battery to the alternator "+" post. That is your charging path.

I would not run a 94 amp alternator through the stock 10ga wire. run a 6ga from battery to alternator, and leave the white charging wire disconnected at the alternator, but leave the fusable link connected at the battery...

Also, the yellow with white stripe at the voltage regulator is the charge warning light, so if you are using a later GM alternator, you can use this...

 

[brider]

cruiserbrett:

You've answered all my questions EXCEPT:

I see the + wire from my batt going down to the starter, where it's bolted to a post with a fat white wire. I assume this is the charging wire.

Where is the "...fusable link connected at the battery..." you speak of?

 

[cruiserbrett]

you've got a PO wiring mod. there should have been more 10ga white wire, enough to go to the battery, and there would have been a fusable link there attached to the positive battery cable terminal...

Anyhow, so your charging path goes from alternator to starter post via white wire and to the battery through the large positive battery cable.

 

[inkpot]

you've got a PO wiring mod. there should have been more 10ga white wire, enough to go to the battery, and there would have been a fusable link there attached to the positive battery cable terminal...

Anyhow, so your charging path goes from alternator to starter post via white wire and to the battery through the large positive battery cable.

Howdy! According to my Haynes ( I know it just a Haynes) the fusible link did not show up in the 40 or 55 series until 1972. I think they just used an extra large gauge wire to carry the load for charging the battery.I don't think it would be a bad idea to add a fusible link, especially if you are running an alternator that is bigger than stock. John