Starter or engine?

Question

After 15 minutes of going 20 mph, I shut off for a layover, and my truck suddenly would not start. 1980 Chevy 350 V8, carbureted, no computer. Turn the key, no "clunk", no whizzzz, voltage dips very significantly, like down to 8 volts. Brand new battery, fully charged, 12.8 volts open-circuit after several tries, cables look good and are not getting hot.

I had maybe a dozen tries of 1 second each (stopped immediately after not hearing cranking). 60 minutes later, starter was still too hot to touch. Getting the wires off the solenoid was like "ow, ow, ow".

Pulled the starter off. Reached in with the corner of a crescent wrench and caught a flywheel gear and tried to turn. Levering against the starter hole it was fairly difficult, not super easy. Is this normal? There was no indication whatsoever that the engine was unhappy. Oil looks good. No smoke, anything like that, engine has been a pussycat.

Benched the starter using a 60A cart-sized battery charger for power.

Test 1: Clipped - on frame, + on the starter side of the starter-solenoid, spun up but not into infinity. Amps pegged out well past 60A and did not back off once the motor got up to speed.

Test 2: - to frame, + to starter solenoid via a #14 wire. Solenoid snapped loudly (which it definitely did not do on the car) and gear advanced. No spinning as expected since the motor was bypassed. Starter solenoid alone drew 40 amps!. The arcing from flashing the #14 wire to the charger clamp was impressive.

I find it difficult to believe that's normal, seems like 40A would soon fry the ignition switch.

Test 3: - to frame + to big lug on solenoid. Put #14 wire against lug, solenoid snapped, gear advanced and spun.

What could be wrong? Does the stiffness of the flywheel seem normal for a 350? Is the very hot starter normal? Is the solenoid pulling 40A normal?

Answer 1

Your first sentence states "After 15 minutes of going 20 mph, my truck suddenly would not start." This is more of an issue than the starter. If the engine dies while you are driving, it can be very dangerous. You need to know find out why it dies.

• It would be very difficult to rotate the engine with a wrench against the teeth of the flywheel thru the starter hole. This is normal. The engine has compression and lots fo moving parts you would not have the leverage to move easily. The starter is geared specifically to overcome this.
• The first test you did, with the charger attached, indicates you had it hooked up in reverse which resulted in it spinning backward. Therefore, the gear did not slide forward, like it did in the second test when it spun in the proper direction.
• The starter is no directly connected to your ignition switch for the exact purpose you stated. It could not handle the amperage. There are relays and the solenoid that is designed to route and handle the amperage.

Just because the starter spins, doesn't mean it is working properly. It could be failing under load. The fact the starter is hot to the touch indicates that it is shorting out internally, or in the wiring going to the starter from the battery.

My guess would be the starter.