As best I can tell, there were two types of cruise control used on this vintage truck. One was the old vacuum servo and some had the newer electric all in one servo.

I am trying to determine if I can retrofit the electric servo onto 73-79 model columns and need to see a wiring diagram for the electric cruise servo.

Thanks

 

And the year, series, engine size of the truck is...?

If you ask questions without giving a single shred of evidence of what the hell you're working on, how do you expect others to help you?

 

I was hoping to find a guru with '87-91 trucks that they could say "A (year/model/engine) has electronic speed control and here is a diagram." If I could just get year/model/engine has electronic cruise at least that would give me a live rabbit to chase.

I was trying to not put a lot of extraneous content in the post that really wasn't relevant to this era of trucks, but here goes.

A 1979 F series steering column uses 2 commutators plus ground to transmit horn and speed control signals from steering wheel switches to the appropriate places. This setup continued until the '91/92 body change at which point Ford went to a plastic clock spring having 5 or so wires in it.

Mid '90's electronic speed control servos require a minimum of 3 wires plus ground to make them work, the other wires going through the clock spring being lights and or air bag.

Finding good '79 steering wheels is difficult and finding a good set of SC switches is about impossible but finding 87-91 ones are relatively easy and I have several nice sets.

An 87-91 wheel will fit a tilt 79 steering column using all factory parts if you change the top short end of the shaft owing to the fact that the 87-91 wheel uses an indexed spline whereas the 79 does not. An 87-91 wheel will fit a prior column if you take a Dremel and remove 1 or 2 splines.

If one cannot find the proper vacuum SC setup for a 78-79 you can use an 80-86 amplifier and vacuum servo but you have to rewire the column plugs in order for it to plug and play.

Ford uses a series of resistors in the SC switches in order to tell the servo what button is being pushed so trying to interface factory switches with aftermarket servos is a no go without going through an Arduino or something to try to interpret signals or some such tom foolery.

Problem: My 1955 F100 with a 1979 column had aftermarket Rostra speed control on it which died and I would like to run factory parts with switches on the pad?

I know for a fact that you can run mid 80's vacuum SC amplifier re-pinned to 1979 wiring with the mid 80's vacuum servo on a '79 tilt column with an '87-91 steering wheel in a '78 F250 and have all of the buttons work properly.

I know I could use the same setup in the '55 but I would like the less hassle of the electronic SC. Did Ford build an electronic servo unit that only required 2 wires and a ground during the 87-91 period?