Folks, on my '88 f-150 4.9L manual tranny, the starter sometimes won't disengage -- maybe once every 30 starts. The engine starts and turns it off as it should. With the starter still cranking and ignition switch off, a light tap on the fender-mounted switch gets the starter to disengage and stop. Or pulling the small wire from the switch gets it to disengage. I'm on my 3rd switch, all different brands -- but none were Motorcraft. Current switch is a Standard Blue Streak. Could I have yet another bad switch?

FWIW, recently replaced starter, alternator (there's a story there!), battery cables. The switch problem didn't change -- it had been happening before those replacements.

 

That looks two different issues. If too much current is repeatedly pulled across the contacts they tend to stick together and cause this issue. Then you state you can remove the small trigger wire from the the relay and that de-energizes the relay too. The latter is probably caused by a mis-adjusted ignition switch or it too has a bad contact (sticking). The ignition switch is mounted on top of the steering column nearer to the firewall. If this has happened repeatedly it could be burning up your starter relays.

Does the key cylinder feel like it catches or sticks when cycling the key from Run to Start and back?


Look closely at those aftermarket parts. If they are made in China they are pure garbage. And they will not stand up to the hanging start signal you appear to have.


Did you replace both the positive and negative cables?

 

I am not versed on your issue but my gut says you might have a bad starter or the incorrect one. And it is certainly possible that you have another bad switch but.........Then again since you can stop the starter by tapping the fender that would lead me to believe you have a short or bad connection. This may go with your statement of (there's a story there!) that you mentioned. Sandy

 

A Motorcraft fender mounted relay (solenoid) is under $25 on Rockauto. You can probably get one from the dealer in 1 day if you order before 10am, depending on the dealer. Cheap, made in China, or other inferior ignition, cooling, heating parts should be AVOIDED at all cost. Saving a few cents or dollars isn't worth the headache.

All the Motorcraft solenoids on the fender I have seen say to replace with OEM or electrical damage may occur. This was the truth when my boss came to me with 3 starters burning up and the fender mounted relay(solenoid) sticking or the contacts WELDING together.

Hopefully there hasn't been any damage to starter after all the relays have been sticking.

 

rla2005, the ignition switch operates smoothly. At least one of the starter relay was made in China, not sure about the Standard Blue Streak one. Yes, both cables. Thanks!

 

The short version of the story about the alternator: mounting bolt frozen and could not remove it, so I used a reciprocating saw to cut the alternator out, then the bolt. The new alternator is working well.

 

I don't see a Motorcraft switch on RockAuto, O'Reilly's, or NAPA. Hate to go to a Ford dealer....

 

I had to change the year from '88 to '90 something.
Here it is...


Motorcraft SW1951C is what you need, correct?

When looking for parts, change the years and new updated parts are available and sometimes Motorcraft is listed too.

 

I agree replacing the starter relay (again) is probably in order, but confirm you can get the relay to disengage by removing the trigger wire. As I previously stated I think you have two problems, but one is triggering the other. If the issue is gone after pulling the trigger wire start there before ruining another relay. I know I can read your first post again, but just confirming 100% that is the case.

 

Definitely stay away from el cheapo starter solenoids. I've seen this problem happen more frequently with the older style solenoid on vintage Mustangs, but have heard of it happening on our trucks as well. Interesting, when I search for my 94 Rock Auto doesn't list a Motorcraft one. It should be the same SW1951C.