My sons truck 1986 F250 2WD 351 automatic has a starting problem. The problem is the starter engages and will not disengage. It runs the battery down
and stays egaged. Replaced starting selinode and will restart with jump. It will
start alright a few times then will do it again. The starter is new. Any ideas would be appreciated.

 

Only one thing can keep the solenoid engaged and that is the coil wire. The coil wire oonly has voltage when the key is turned to the start position. One thing you can try is bypass the ignition switch by switching the key to the on position and use a remote starter at the solenoid. This will prevent the ignition switch from engaging the start position and you can continue this untill you determine that the switch is NOT the problem. Other than that you can replace the switch (it's on the column) in a shot gun method of troubleshooting. Checking the voltage between the starter cable and ground will tell you if the solenoid is stuck on. You could wire a small indicator light there and be able to check it at a glance.

 

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You have replaced the solenoid that is beside the battery at the other end of the positive battery cable? Try removing the small wire from the solenoid and see if the starter disingages. There's not much to this circuit. If there are 2 small wires on your solenoid, any chance that you have them reversed? Is you ignition switch operating properly? Smooth action, and returning to the run position properly? Let us know.

 

Yes have replaced the soleniod and wires are in proper places. Key moves freely
and springs back to run. Have not tried pulling wire that goes to switch when
stater is engaged.

 

yep sounds like a bad ign. switch -- not the key switch 2 differnt things !!!Just did one on a ole 73 maverick , poor kid had replaced the starter relay 3 times an the starter 2 times , he was a tad pissy ,, oh well .

 

There is a rod that travels from the column switch(key switch) down the steering column to another switch at the bottom of the rod. It's likely that switch is the problem and needs to be replaced.

To make things easier(still not the easiest thing to get at) pull the bolts that hold the column to the dash, after removing the covers, and let the column rest on the seat. This will make the switch accessible with minimal removal of parts. It's not an overly expensive part. I think I payed around 15 bucks for the last one I replaced.

 

Is the starter new or rebuilt, and where did u get it from?

 

the starters rebuilt parts store , two different ones. also replaced ignition switch

no change same problem. did pull wire off s terminal when starter was stuck open and starter stayed engaged. what is left to replace ?

 

Has to be the solenoid sticking if you aren't powering the starter through that wire and it is still getting juice. I don't see how it can be anything else.

Either the solenoids are sticking and you just had bad luck with another bad one or else the wiring must be wrong.

On my 86, I only have one small wire on my solenoid and it is a red wire with a green line that comes from the ignition switch. Mine is a 302 but I can't imagine that a 351 should be any different.

As Holmsuser said, there isn't much to this circuit. If you pulled that wire off and it is still doing it, then either the contacts are sticking or a wire is wrong and it is providing power to the starter by bypassing the solenoid which is just a fancy word for a simple relay.

I would double check the wires, then check them again. If all else fails, go back and demand another solenoid and tell them that one is defective.

Do you have a Haynes for reference as to what wires should be where on that? Any chance there is another truck around like it to compare it to?

Good Luck,

Lee

 

you got your relay. solined on the fender , ,,, with the battery hooked up ,, Disconnect the starter wire (heavy wire going to the starter ) take a test lite, On the 2 big post only the one coming straight from the battery to the relay should lite up the test lite. now put test lite on the other big stud it shouldnt lite up ( if it does the relay is stuck) ,, Now with the key off the lil wire should have no power to it ,, Turn the key to the on postion it still shouldnt have power,.. Now turn the key to start the lil wire should lite up ...( you might have to adjust the ign. switch you just replaced if it dont work like that ) ,, The one big stud on the relay allways has power , the lil wire when held to the start postion -- makes the other big stud have power, which runs juice down to the starter to make it spin,,,, If both big studs have power with the lil wire off - or no power to it , the relay is bad------- Some trucks have several small wires with a large ring term. on them that will fit on the big studs -- do you have these wires on the right stud ???

 

make sure that the solenoid is bolted tightly to the fender.

 

Hey alll....New to these forums...New to Ford trucks too....Just aquired an 85 F-150 351W 4 months ago...Engines strong, bodies decent...

But in reply to this message reminds me of what I just went thru myself....

Long story short, I went to install some new mufflers on this truck..(Glasspacks)..Didn't even touch the ignition...So I cut off the ole mufflers and went to start the truck...and nothin but a brake light staring at me...with no starter activity..

So I swapped the solenoid and it started tight up....Next day, went to continue with installing the muffelers, so I figured I start the truck first without the original mufflers installed so I could here a WO 351W.....Popped the key in and nothing but bzbbbzbbzzz and the spin of the starter was heard, but it never engaged....

So I proceeded to jump it from my wifes Jeep...The truck did start, so I figured dead battery was the root cause...After 20 minutes of running the truck, I got out to investigate under the hood...Ughhh, the battery was spewing acid all over out of the pos battery post...

So off to Advance auto I go again....I picked up a Voltage regulator and slapped it on and I also aquired an MSD 8227 Ign coil as well, so I threw that on and of course a new battery went in...

That was this past weekend, and so far so good...By end of day Monday, I actually managed to get the mufflers in place tooo...

So I guess, if you have my luck, it may not just be one thing at fault, but it may be several things causing this issue on your truck...I just hope it all works out for ya.......

Andy

 

Any one who has replaced their solenoid with a GP Sorsenson (Advance auto brand crap)- be for warned:

I've had not one, but two within a month's time, stick and keep cranking like this.

So, I replaced them with junkyard OEM models, and they work fine.

 

I hope that's not the case...I've usually had good luck with the GP Sorensen stuff..I know it's not the best........

Maybe you just had a streak of bad luck...I guess I'll find out soon.......