Is it possible to override the cruise control servo for idle control/hand throttle instead of using a manual cable? I know the tan/red wire is the vacuum and the lt green/red wire is the vent control, but I don't know how these cruise controls and servos work. I don't want to mount a cable and I think it'd be pretty custom to mount a switch just like they have in big trucks for the cruise and PTO throttle control.

 

not sure you need to be able to apply power to one to make it work i would check it with it on if you have a dynometer avalible

 

Yes.

I made a circuit to simulate the VSS on a chevy and wired it to the electric cruise box. I can put my idle wherever I want on my gmc using a variable dial


I have cruise on my first gen.. i'll look into it but i'm pretty sure it runs off vacuum? that would be a bit harder to do.

 

The servo is electric over vacuum. There are four wires from PCM: 12V positive, ground, vent & vacuum. I was assuming applying 12V to the vacuum wire with cruise on would apply vacuum & pull the throttle just like bumping the cruise up - except wiring in a separate switch. Apparently the PCM won't let me do this cuz it's not getting a signal from the VSS that the truck is moving. Wiring a dummy VSS circuit with a pot to control the throttle sounds like an idea, maybe I'll give it a try. It would probably be easier to just throw a cable in for a hand throttle, but definitely not as original. Thanks alot for your help guys. I'm still always open for more ideas though...

 

my 90 has a hand throttle in it. dodge brackets an all, never use it since i once forgot it didn't come off with the brakes and dam near smashed the back of a car. but it does work nice for warming the truck up

 

Your truck had a factory hand throttle?