tmsfreon

I have a 91 F150 with a 302 V8 and a manual transmission. Last week one day when I went to start it the starter stayed engaged, and I couldn't get it to stop. I unhooked the battery cable to kill it, but every time I would start it the starter would stat engaged. I ended up unhooking the cable from the starter solenoid switch mounted on the inside fender to the starter and when I have wanted to start it since, I just touch that cable to the post on the solenoid switch and it will start but I have to remove that cable from the post otherwise the starter just stays engaged.

I have replaced the ignition (key), replaced the clutch safety interlock, the solenoid starter switch, had the starter and the solenoid checked by two different shops and neither can find anything wrong with it.

I have checked the starter solenoid switch for voltage, and it is in the spec range I have been told it is suppose to be.

So any ideas??? I am stumped.

88xlt

A starter system is very easy to understand, once you realize how it works. On a 1991, assuming you still have the original 1991 system and you probably have.

With the problem you're having it can't be the starter itself. The only way the power can get to the starter is through the fender mounted solenoid. SO, I repeat SO, either your fender mounted solenoid is sticking engaged(it sounds like you already replaced it I know) OR you are getting power to the solenoid From the ignition switch THROUGH that little slip on wire that hooks onto the solenoid.

I'll try to make a simplified bottom line here. If you unhook that little slip on wire from the solenoid, and the starter still spins when you connect the cable going to the starter, your fender mounted solenoid is bad. NOW if unhooking that little slip on wire from the solenoid stops the starter from spinning, you are getting feed from the ignition switch when you shouldn't.

tmsfreon

Thanks, I will give it a try and let you know what happens.

hotrod69boss

Hey tmsfreon, did you get your starter figured out? I am having similar problems as posted 9-5-2016 on general f150 discussions under I need help.Any suggestions? One guy said my alternator must be the problem. I just dont know.

seschenburg

A solenoid is part of a relay. It's also called a coil since it is simply a core structure with wire wrapped around it. A relay is a solenoid + the related electrical contacts. The term relay and solenoid are often used interchangeably, but there really is a difference.

The only thing that provides power to the starter is the starter relay mounted inside the fender behind the battery. So, power must be getting through the relay somehow.

Three possibilities:

1. Either the internals of the relay are damaged resulting in a short between the battery cable and the starter cable.
2. The relay is wired improperly.
3. The starter is wired improperly.

You can find wiring diagrams through Google.

Never take your car back to the guy that blames your alternator for a starter problem.

hotrod69boss

Mr. Seschenburg, Thanks for the info.My truck has not acted up since my last post. One guy suggested a short in what I call the exciter wire {the small push on wire to the fender mounted solenoid}. He thought the wire was sending power to the solenoid engaging the starter but not allowing the starter to disengage because the exciter wire was a fusible link and had broken its connection while the solenoid was sending power to the starter. I presume he meant that power was required to disengage the solenoid. I will check out the wiring diagram as you suggested. Maybe I will get the answer to my problem. Thanks again for the info. Very few people have replied to my post. All info is appreciated.I guess I should not have been sleeping while the Ford electrical professor was lecturing.I know just enough about electrical systems to electrocute myself. Thanks again my friend. Rod P.S. Another guy said my truck had very acute hearing and if I spoke badly about it I would wind up getting stranded on some lonely deserted north Texas road around here!

Chris_1

iTrader: (1)

You don't need power to disengage. If you are getting power to the 'exciter wire' when the key is not turned all the way to start that will cause the fender mounted relay solenoid to stay engaged which will in turn cause the starter to stay engaged. Power to that wire will be coming from the ignition switch which is mounted 1/2 way down the steering column (not the key tumbler).
That 'exciter wire' should not have power at any time except when you turn the key to START.

seschenburg

Chris_1 makes a good point.

When I read "...every time I would start it the starter would stat engaged ..." I interpreted that to mean that the stuck starter only occurred after turning the key and starting the car. And that once you "...ended up unhooking the cable from the starter solenoid switch..." that the starter would go off until you tried starting the car again at which point it would continue running unless the cable was disconnected.

So, if my assumptions were incorrect, consider that the ignition switch or the wiring in your steering column could also be damaged.

Chap150

My first question is, how did the two different shops test the starter? Did you take the starter to them and they laid it on a bench and put a battery charger on it? If that's what happened then I bet the starter did exactly what its supposed to do. Spin. Engage. Release. It wasn't under a load.

The solenoid is more that just a power source. Its a spring loaded mechanism that when power is applied to it, it engages the ring gear to spin the engine to fire and then it disengages the ring gear/flywheel, going to a restful state.

The short of it is ....

Replace the starter solenoid. Or both starter AND solenoid. It's had a good life. Get a new one.

Chap

bcurbox

My 91 F150 302 auto has an intermittent starter staying engaged once I go to start it, it will stay engaged once the engine starts/runs, also stays engaged once I turn off the key (even pulling it out). So I would jump out of the truck, grab my hammer (only because it is in reach each time), open the hood and tap the fender mounted solenoid which in turn will immediately stop the starter from continuous cranking. I can usually go inside the truck and start it back up without it happening again. This happens every 2 or 3 times I go to start it. I've read some people say it's because of the bolts on the starter are not shimmed correctly, and others say the back of the solenoid on the inner fender is not grounded to the fender. I have yet to go out and try cleaning the back of the solenoid to fender for a better ground, but has anyone else had this issue? Yes, tapped the solenoid with hammer lightly stopped it and can drive on is only a temp fix for now.