1990 F-150 4.9L w/E40D transmission.
Cruise control has failed.
Does anybody have a step by step diagnostic procedure to evaluate this system?
I have the Ford two volume shop manual but is not very helpful, well at least not to me!
Are there any fairly detailed step by step procedures for checking the various control pieces out in this system?
Any advise and or guidance would be greatly appreciated.
Thanks.
DaveP Kywoodwrkr
(Name says it all-maybe I shouldn't be working with electrical/mechanical things!)

 

I'm no expert but if your airbag light is blinking a 3-2 code, your cruise typically wont work. You'll need to replace the clockspring.
Also I beleive cruise is held by vacuum pressure so i'd start there, maybe a bad hose.
Popa Tim

 

Remove the ground cable off the battery when you have to work with the wiring. There should be a fuse for cruise control.

 

If your horn doesn't work, along with the cruise (and the airbag 32 error) it's the clockspring. I have a few pix in my gallery.

 

if none of the above work, take the cruise sontrol buttons out of the back of the steering wheel and clenn the contacts, and check the cruise control servo/computer wich is located by the master cylinder on the fender and take the top off of it and check to make sure that the plastic gears inside are not all stripped out.

 

Thank you one and all.
Printed out the replies and will endeavor to follow up on this weekend when I can get to the truck.
No one has a point by point diagnostic however, right?
Thanks again.
DaveP

 

http://www.dalidesign.com/hbook/ccmain.html

here is a site I used to troubleshoot my cruise control
hope this helps!!

 

packrat,
Thanks very much.
That link, combined witht he other suggestions should get me fairly well acquainted with the unit(s).
Again, thanks one and all.
Now to get time for the analysis!
DaveP

 

Dave,

Since you're persistent AND a fellow woodworker, send me a private msg with your email address, and I'll send you the specific TS steps.

 

Ladyfire,
e-mail address is
david.petersen@eds.com
I tried the PM thingy but I haven't enabled it on my profile so can't send either.
Besides woodworking, I've been in computers since 1962 but you sure couldn't prove it! :-|
Thanks.
DaveP

 

Goto "User CP" in the upper left of the screen. Click on "Edit Options" Scroll down to the private messaging section & enable the parts you want.