Fourth wire to Starter?

[JIMDINK]

After removing the starter on my 74 Jimmy I discovered a random wire with a fusible link hanging next to the starter wires with no end on it. It's the same length as the starter wires do I assume it used to be connected to the starter. I tested continuity back to the fire wall but can't tell what it is for. Can anyone tell me what it is for and if it connects to the starter? And if so, which post?

 

[Barrman]

Does it go to the diamond shaped junction block on the firewall by the brake booster?

 

[JIMDINK]

Square shaped but yes

 

[JIMDINK]

It's the black wire on top

 

[Barrman]

That is the thru firewall harness plug. I’m not going to try and apply my 1985 wiring diagram to your 1975. But, you need a schematic for your year to find out where it goes and what it is supposed to do.

 

[Wes Harden]

I would say that is a fuseable link and it should be connected to the battery stud of the starter. But if you have been using the truck, where is the power that fuse link is supposed to supply coming from??

Are there any PO additions that you don't understand ?

 

[RaisedK5]

If I'm reading the wiring diagram correctly the black wire to the starter is circuit 105 which should go to the ampmeter. Does your ampmeter work?

 

[Wes Harden]

Most early trucks use the amp meter to power the rest of the truck. Basic principle to make the amp meter do it's job.
Still has me scratching my head, were is the power coming from.

 

[500$k5]

On Chevy's, anything at the starter with a fuse link, should be attached to the positive battery cable post, on the starter.

 

[JIMDINK]

On Chevy's, anything at the starter with a fuse link, should be attached to the positive battery cable post, on the starter.

That makes perfect sense to me. The starter didn't have any random terminal on any of the posts so it was sort of a mystery.