The Stovebolt Site Forums The Shop Area Engine Shop Starter failure

I'm thinking I may have a starter failure, but curious as to everyone's input. I had my starter tested 3 years ago when I had my 261 rebuilt and it was in good shape, so I did not have it rebuilt. Yesterday, I drove my truck to the gym, everything working just fine. When I left the gym, I hit the starter and it sounded like the battery was going dead. Slow to turn over and the starter sounded very strange - hard to describe but didn't sound smooth and balanced as it normally does. Tested my battery charge, it was at 85%. Ran my fingers over all of the connections and all looked solid. Hooked the battery back up, hit the starter, and nothing. Dead. Pulled the starter and can't see any sign of damage, starter gear moves back and fourth just fine. (Side note, my truck starts very quickly, I never have to engage the starter for more than about 5 seconds.)

There's a small alternator/generator shop close to my house, I'll run it over tomorrow and have it looked at. Does this sound like a starter failure to you all?

Among both ends of both battery cable connections, the connections at the starter solenoid if you have one and the starter itself removing the starter for testing is the hardest thing to do. I'd do the others first.

6 volts? You must have good clean battery cable connections at the battery, at the starter and at the grounding point on the engine/frame.

12 volt setup. Battery cables are clean at both ends, battery is 1 year old. Group strap looked ok, but I pulled it off yesterday and hit it and bolts/connections with a wire brush, surfaces very clean now.

Assuming the 12 volt setup and you have a voltmeter, I'd start like this with a totally assembled electrical system.

Measure and record the voltage between the battery's positive and negative posts with the key off.

Measure and record the voltage between the battery's positive and negative posts with the key off and the headlights on.

Measure and record the voltage between the battery's positive and negative posts with the key on and the headlights on.

If all 3 measurements above are not at least 12.5 volts the battery is either defective or not charged. Solve that problem before continuing.

Once you've posted those results we can proceed to the next steps.

Tested, and all readings were above 12.5.

Took my starter in to a small electric shop, pulled the top off, and about a pound of dust and dirt came out and the brushes were frozen. Heavily worn. Pulled the switch off the top of the starter and the electrical contact point was also very worn. The guy was quite surprised it had been working up until last week. Needless to say, it's getting a full rebuild.

I believe the brush holder design limits how far the brush can travel down (wear) to prevent armature damage. Black dust will be from the worn brushes.
Wear on the electrical contact is normal. I'd say that starter has provided many good cranks in it's long lifetime.