Went to work this morning, I got out of the truck to dump some trash in a dumpster and thought I could hear a fan like sound coming from the truck.

When I parked at work and switched the truck off the starter kept turning, even with the switch off. I switched it back to the "on" position and the truck began running again. I did this a couple of times. When the starter quit turning I opened the hood to find a small fire on the starter. I doused it with a mason jar full of water. I had to do this twice. The starter has been replaced. I'm just glad I wasn't far away from home when this happened.

My truck has a 300 six so the starter was easy to get to, if it had been a V-8 it could have been bad since the starters on them are hard to get to on most of them.

 

I hope you replaced the solenoid as well. Generally when the starter won't quit turning, it's because of the Starter relay on the fender.

 

No I didn't replace the solenoid, but I will. Thank you for letting me know about that.

Smitty

 

I have personally seen this problem three times just as stated after a replacement starter had been installed, as a rebuilder I get some of these challenges, the first is the starter solenoid on the fender should be replaced with the starter, it also needs the solenoid with the diode in it, the diode stops voltage from going back up the line and holding the starter engaged. The second item is, did you get like for like starter, some of the earlier 88-92 used a 4 1/2" starter unit on the L6, if the starter was replaced with a 4", there seems to be a problem that does not show up until it is too late, third, drive gets hung up on the flywheel, drive goes through the flywheel and hangs up on the backside not letting the drive come back to the starter upon shutting off the starter. Hope this helps, Broken Wire

 

This message is for "Broken Wire". I am the owner of the thread "1989 F150 4.9L sterter issues". I have replaced both the starter & the solenoid- the new solenoid has two small terminals. I used the one labeled "S", per the instructions - this was the only connection that I replaced when I installed the new solenoid, as the wire was badly rusted & I destroyed the connector. The only wiring difference is that I cleaned all wires going to the solenoid switch. See my thread for the issues. NOW that I have cleaned the small wire, I have tried 3 solenoid switches - the old one (labeled "Diode" - with only three terminals) & two new solenoids- both with 4 terminals. Now the starter engages as soon as I hook up the battery terminals. I have NOT actuated the ignition switch.

1) Are there different solenoid switches, because the parts suppliers sell only one type?
2) Could it be a poor grounding issue, because the negative battery terminal wire casing is broken & the wire stranding is corroded (green)where it is secured to the frame, but the cable is complete & strong (no broken strands)?
3) If the small wire is the issue, what is the voltage & where does it trace back to?
4) Where do I get a good wiring diagram?

 

I'll get that solenoid replaced.
And thanks for the great advice.

Smittyd

 

No there is not different solenoids, just the 3 and 4 wire if you are asking for a solenoid for a Ford, the diode unit was to be used with the PMGR (permanent Magnet Gear Reduction) starter unit, it also is the starter with magnets inside, the problem appears from what you are writing is the small wire, (red and blue)? Just taking from memory. The wire goes from the solenoid to the ignition switch. The small wire is energized when the ignition switch is placed in the start position only. Testing is check r/bl wire with test light with wire off solenoid, if it is lit, take wiring off ignition switch and retest r/bl wire at solenoid, if it is still lit, wire is shorted to power, if it is not lit, highly suspect ignition switch problem.
3 wire solenoid: 2 big posts, 1 power feed, 1 power output, small lead excitation of solenoid.
4 wire solenoid: 2 big posts, 1 power feed, 1 power output, 's' term= switch, 'I' term= ignition, 'S' terminal energized with ignition switch, 'I' terminal energized after ignition switch is placed in the start position, 'S' terminal is just a contact inside the solenoid, was used to feed 12 volt power to point ignition system direct to ignition coil without resistor lead, faster startup. Wiring diagram: I sent you a personal message, check it.
Hope this helps, Broken Wire

 

I had the same thing happen to me when I was driving at about 50 mph. Talk about a bad noise, that starter was spinning at a few thousand RPM. I stopped and turned off the truck and the starter was still enguaged. Had get get some pliers from the tool box in the back and break off the battery cable to get it to stop before it caught fire. Took the starter back to Napa ( 6 months old) and the guy told me that I had got it too HOt. Really it was spinning the same RPM and the moter at 50 MPH.

Scott

 

WOW -- That was bad. I replace the starter as well as the solenoid on mine, I hope it doesn't happen again.

Thanks for the reply,
Smitty