Golden Jubilee
Posts: 5177
Joined: Thu Nov 29, 2012 9:28 pm
Location: Lyman, IA
Re: 1971 1210 pickup
Rather than cut or re-wire willy nilly. dope out what you have now. Field must alsway go to field. If the R terminal is not used on the alternator, than some other way of determining when to switch on the alternator is used . Ign feed is a common way.
Term 2 is what open an closes the relay, tem 3 gets connected to term 4 when the relay closes, and is used to feed the field and operate the regulator. On a truck without a "charge light" term 4 can be used for things that you want power for only when the engine is running, like an electric (or electric assist) choke. You don't want to connect a heavy load directly to terminal 4 as it would have an effect on what the regulator "sees' as system voltage, but it may be used to trigger another relay for heavier loads. I don't have diagrams for your truck so don't know for sure what was done.