1970 Chevy Truck attention VetteVet

[randy500]

You could also check the running condition of the belts without the alternator load by unhooking the single wire to the alternator, it goes straight to the battery so tape it up before starting the engine, if the engine runs without belt noise and the pulleys run true and the V belt is not bottomed then your problem with screech and burning up belts is high electrical load.

[VetteVet]

Great advice Randy and Richard.
Moon Since I know that you have the IR alternator it simplifies the wiring somewhat. All you need to do is to identify the NO.4 ( 16 gauge brown) wire to the old external regulator and connect it to the alternator no. 1 terminal if you have bought an SI series alternator. Then you can connect the red wire that went to the old regulator to the No. 2 terminal.

Here's my diagram of how to wire it up.




You should also upgrade the large output wire to a 10 or even 8 gauge wire for higher amperage carrying capability. Then run it to a junction with the battery feed wire and the wire that feeds the cab.

Here's a real life picture.



The junction for your truck is taped up in the wiring harness down by the left headlight and it will be on the end of the original external regulator red wire, and the end of the alternator wire as shown in my diagram. Here is what it looks like in real life.



This is the junction from my truck. It dies not have the small 18 gauge wire for the battery gauge in the dash because I have an idiot light dash. one of the red wires in your fuse panel may come from there to feed the fuse panel in the cab. It depends on what the guy did who wired it for you. I replaced it with this one which is in my truck now.