93 F-250 Cruise control Issues

[mn_HIGHVOLTAGE]

I have a 93 F-250 with the 7.3 Diesel. I have been working on the cruise control for over a month now and I am determined to figure it out. This is my precess so far. I did a little putzing around, checking fuses relays safety switches etc, until I got ahold of the Toubleshooting procedures. in this link.
http://http://www.justanswer.com/ford/2dcq2-93-ford-f250-7-3-desiel-cruise-control-went-out.html
Everything passed with flying colors and at the end it says basically if it passes, replace the servo. I replaced it with a recycled part, and STILL doesnt work. My only thought is that the Servo I removed had the following part # F2TF-9c735-AB. The replacement I got from the JY was a F2TF-9c735-AA. They are completely identical and the JY owner said that stuff doesnt matter, It came out otf the same year truck just different engine. Could this matter? One other thing that makes me wonder is that when I am testing the resistance of the switches it seems to fluctuate all over until settling on the proper resistance. Any other ideas? I need help with this.
Thanks
-John

 

[Howlndog]

Hi,
I did a search for my needed part number and your post from 2011 showed up. I have a 1993 Ford F-250 with a 460 engine and presently the cruise control does not work in it either. I have trased it down to the servo. The servo in my truck is F2TF 9C735 AA. Your post states you bought that exact servo from the junk yard and it didn’t work because you have a 7.3 Diesel engine. Some of us Ford junkies keep all that stuff we get in case we might need it some day. I was hoping by chance you still have that servo laying around somewhere. If you do, and you would like to sell it, I would gladly pay you for the part, and your trouble to send it to me plus the postage. Well, anyway it was a shot in the dark and I thought I’d try it. Thank you again.