my uncle has a 91 f150 302 auto. he has replaced the ignition switch and starter solenoid. but after starting the truck the starter still continues to run. its like the switch isnt coming back to the run position but it is.....any ideas. Mick

 

Since no one has replied to this, I'll take a shot at it.

I don't know how the starter works in that model. Does it use a separate relay or does the starter switch wire (a small wire in addition to a LARGE battery lead) connect directly to the starter? If a separate wire then see if it's still getting power even after you release the starter switch. If a separate relay, then see if it's sticking and still sending battery power to the starter even after you release the start switch.

IF the starter isn't being told to engage and run via either of those methods then see if the small starter gear is sticking on it's shaft. Normally it's retracted from the flywheel (or ring gear) unless the starter is engaged. When the starter is engaged, the gear slides on it's shaft and aligns with the large gear on the flywheel and the starter spins the engine via the small starter gear and large flywheel gear. When you release the starter switch, the starter should stop spinning and the starter gear should retract back out of alignment with the flywheel. However it's not uncommon for the small gear to stick on the shaft and not to retract due to wear or burrs on the shaft or due to a lack of lubrication and still be engaged with the flywheel when it shouldn't be.

 

it has a solenoid switch....which I believe when he replaced it he went with a cheap switch. So we are goin to replace it with a better quality switch. but i will check the wires you mentioned. I appreciate your time and help

 

Check the output of the solenoid and make sure that it's actually turning off when you release the key. It sounds like it might be sticking.

 

Sure will.😃 thx

 

Nice comment J0E51. One last possablity is that the ( small started gear) bendix gear shaft is binding in the two bushings when it has load. When it binds the bendix can have problems releasing from the flywheel. (common old gmc problem) I do not know what that year starter looks like, but if the housing that covers the lever that moves the bendix gear on its shaft has been dented or has come loose it may prevent the lever from retracting the bendix gear.

 

Problem is the truck is 45 mins fro. Me....this is the 4th stater he's been through in about 2 months..he didn't say if the starters were staying engaged to the flywheel. .jeesh I'll have to find out more info....I think it's in the cheap solenoid he bought.

 

Cheap parts aren't worth what they cost in time & frustration. A MotorCraft reman starter might cost double what a cheapo does, but it's WORTH IT. Shop eBay, but pay very close attention to WHO rebuilt it most-recently. I've seen listings for "MotorCraft reman starter" with the correct MC PN, but it's an old reman that someone else has rebuilt again. You want one that's in a new MC box because MC just rebuilt it.

Some reman starters (not MC) come with a jumper between the main hot stud on the solenoid & the small trigger terminal. If you're going to use a solenoid starter, make sure that's NOT present, and connect the starter exactly as shown in these:

. .

But a '91 probably wasn't built with a solenoid starter; I think it should have the older style, like that last one above & these:

.

Follow the other links in those captions for more info.

 

FYI, Just because they've changed the starter four times doesn't mean that it's not a starter problem! You couldn't believe how many starters I used to have to change out in my old big block Mopars! After 100 times of so, I could finally R%R a starter in about 2 minutes flat. Apparently the same "rebuilder" rebuild all of the ones that were resold in that area because they all had the same problem. Mainly, the dipped the field coil in some sort of insulating rubbery compound and then put it into the steel housing, They'd then drill a small hole through the housing and into a copper strap that was part of the field coil. They'd then put an aluminium Pop-river in and that was supposed to be the ground for the field coil! Needless to say, rubber coated copper, steel and chinzy aluminium rivet didn't last long! After about 2 weeks or the first time that it got wet, the field coil would lose ground and the starter simply stopped working. I use to buy starters by the case (12ea) until I finally figured it out and then rebuilt their rebuilds to make them work right!

 

i really appreciate all the help guys im going to go see my uncle this weekend...i know more now thanks to the help. ill see exactly whats goin on...ill let you all know...i may need more info

 

My 89 302 also had a problem with the starter failing to shutoff (even after the key was removed from the ignition). In my case it turned out that the the two bolts that held the stater in place were the problem. The lower of the two had become lose, while the upper bolt had become very tight. I think this caused the starter to sit in place crooked, and thus would not allow it to disengage.

I ended up taking the starter off then putting it back on, which did fix the constant starter running problem. Also, the stater died shortly thereafter by failing to engage (it was original so I cant say if it was this problem that killed it or if it was age). Either way, if it does die hold on to the original if you plan on going to a auto parts store because if you don't you may have to pay a "deposit" fee.