I have uploaded the test steps and pin diagrams necessary to perform the Interval Wiper Test on your pre-97 F-150, to my website. I know these cover '92-'96, but don't know for sure about '91 and older. They are the four bottom most images on this page. Click on them for a larger image.

Take care,
-Chris

 

Chris,
I was looking at the interior of your truck. Are those the front seats that came (stock?) with your truck? Is the middle an actual seat if needed?

My wife hates my seats, 50/50 split stock. Makes for a hard time getting in the back seat. Yup, I make her sit in the back

Maybe I'll go scrounge the junk yard for sme buckets like yours.

 

Yeah, they're original, minus the crappy fake sheepskin seat covers. The middle seat doesn't move, other than the backrest. The drivers and passenger seats have full range. My truck is an Eddie Bauer, which I know they came in, and I've seen several of them in XLT's as well.

Take care,
-Chris

 

Great!! I think my interval wipers are starting to go on my 96. Now I can test them with your diagrams! Mine are starting to not wrok at the very slowest speeds. Sometimes when I hit the signal, I can hear the click and they'll go. If I turn up the speed a bit, they work fine. No biggie, but at least I can troubleshoot once I feel froggy!

 

Is it a tough project getting the steering wheel off to change the multifunction switch?

...I no longer have any intermitent wipers, just slow and fast. Unless I tap the end of the stalk.

 

You don't have to remove the wheel. From ALLDATA:

Service and Repair

NOTE: On models with tilt column, unscrew the tilt lever and remove.

REMOVAL AND INSTALLATION


1. Remove steering column shroud.
2. Remove switch to steering column tube casting attaching screws, then disengage switch from column.
3. Disconnect switch electrical connectors.
NOTE: Do not damage PRNDL cable.

4. Remove switch assembly.
5. Reverse procedure to install. Torque switch attaching screws to 18-27 inch lbs .


Take care,
-Chris