Replacement starter has 2 terminals, old has 3

Joined
Jan 2, 2017
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54
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CA
Vehicle is a 1989 Chevy Astro Van, 4.3 engine.

The old starter has 3 terminals: S, R, and the battery one.
The new starter has 2: S and the battery one.

The wiring harness has 3 wires: Battery, the smaller diameter one (for S), and the third, which has a large diameter connector on the end.
The old starter was removed several years ago. So, I don't know if all three were connected then. The R terminal on the old starter is a small diameter post, and the third wire connector is large, so if it was, when they didn't match quite as well as the small S terminal and its small post.

The van starts with the third wire not connected. It also looks like given its large diameter you could put it on the same terminal as the battery wire.

Any advice is appreciated, thanks.
 

ArtDecoWorld

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Jan 2, 2017
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CA
Thanks. So is the third wire with the large connector something I should just leave disconnected? Or attach to the B terminal with the B wire?
 
Joined
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Trace this third wire, I bet it goes off to your alternator. Include it with the big battery wire.

I suppose you could put a voltmeter on it as it sits and runs, and you'll get low 12s for volts, not 14s like you should be.
 
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Thanks. So is the third wire with the large connector something I should just leave disconnected? Or attach to the B terminal with the B wire?
Have a picture? I vaguely recall there being 2 wires on the B+ stud of GM products of that vintage but Its probably been 15 years since I touched a starter on an Astro of that vintage. Dont have wiring diagrams at home for anything that old, the manuals are all at work
 

ArtDecoWorld

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Joined
Jan 2, 2017
Messages
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Location
CA
Trace this third wire, I bet it goes off to your alternator. Include it with the big battery wire.

I suppose you could put a voltmeter on it as it sits and runs, and you'll get low 12s for volts, not 14s like you should be.
This appears to be it! I tried it both attached to the battery wire post, and disconnected. Measured 14 .6 volts at the battery connected, and 12.4 disconnected.

You guys are all really helpful. Thank you.
 
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