Starter problem
 

1991 k1500 350 4x4.

Was working fine, then one morning noticed it was a little sluggish to start. Got worse during the day, until it finally quit altogether. When turn the ignition, not engaging the starter motor. No clicking or anything. Just doesn't turn it over.

I took the starter out and took it to autozone for testing. It passed the test. Means the solenoid is working, which kinda suprises me because when it was on the truck it wasn't engaging. Anyway they said there might be a burr or something on the gear because it sounded like it was grinding a little.

Before I replace it, is there a relay under the hood I should be looking at?

No relay for the starter. Just take a good look at the power wires for weak or corroded spots.

check the positive leads above the main crossover structure, just forward of the starter. there are usualy inline fusable link(s) that will fail due to corrosion and years of use.

Battery checks out and leads and connections check out. i popped the starter out, took it to NApa, they tested it. It turns over, but it's getting hot and burning a little, so I bought a new one and I'll pop it back in tonight.

Good to know there's no other relays, I wanted to rule it out before spending the money on a new starter.

The solenoid is pretty much the relay for the starter. Let us know how it goes.

Put in the new starter: problem solved.

Question: some type of sensor is located in the side of the engine block, just above the oil, near the starter. At first I thought it was the Oxygen sensor, but it's not located on the exhaust. Any idea what it is? I broke part of the connecting piece when I was changing out the starter.

Knock sensor.