When I got my Ranger, the truck would start but not run. Was in the process of following another thread and suggestions in it to fix but ran into a new issue.

It was cranking over very well, just not starting and then it stopped and only spins over so gotta solve that problem first. Took starter off and had it tested at Advance and it passed. I could see the gear pop out to engage the flywheel. Original starter but it has minimal wear to the teeth. Reinstalled started and it still just spins.

Is next step to check flywheel teeth for wear? It was originally suggested that the torque converter lockup was not engaging based on what I was told was wrong - would start but died when put in gear. So I bought a new torque converter but we haven't installed it yet & I know that would be an ideal time to check flywheel teeth for wear. All fuses under hood and inside look good. CEL & theft light do not turn on when key is on but I just replaced the cluster so might be a problem with it. Has new LED bulbs in a lights in cluster. Was turning over initially after replacing cluster. Cluster from 2001 Explorer (white face set) which JY interchange says is compatible. It does match my cluster in design.

Anything I can check before flywheel?

 

The flex plate may have broken at the crank, so starter is just turning the flexplate and torque converter, not the crank/engine

And the starter gear may not be strongly attached to starter motor shaft, so it comes out and spins with no load on it, but can't spin the flex plate/engine so starter motor just spins

With starter motor out you can try to spin the ring gear/flex plate, it shouldn't spin much because of engine compression, and crank pulley should turn the same amount as flex plate/ring gear movement
Or use a socket on the crank at pulley end and spin engine while watching, and holding ring gear in place
This is to see if flex plate broke

Yes, could be torque converter failed, and is now direct drive so that puts alot of stress on flex plate when put "into gear", and that may have been why it broke after all the working start attempts

1997-2000 4.0l uses an 8 bolt flex plate, 1996 and earlier used 6 bolt

 

Haven't had help to check the flywheel yet but I did pull the cluster to check bulbs. Theft has a special light & socket but I put a standard socket & LED in. Still no theft light but now my hazards do flash. Turned the LED in CEL 180 degrees to see if it worked. Still doesn't work. When I got the truck the OBD port was giving a communication error both with my home unit and with units at Advance and Autozone. So now I'm thinking based on other threads it may be electrical/PATS related issue.

Also, where can I source those speciality bulbs for the red theft socket? Or is it a set - socket and bulb?

 

Turned out the starter tested as good on a bench test but was bad under load. New starter had it fixed.

 

Good stuff

Thanks for the follow up post and THE FIX