my cruise controll has not worked since i got the truck and i am going on a long trip shortly.any idea where these trucks cruise control fail.what is the first place to start looking after the fuze has been checked.there does not seem to be any vacuum lines to or from.thank ahead of time.its a 1990 siverado with a 305 tbi.with auto tranny.

I,m guessing you dont have a Chilton manual. I can go get mine out of the dust crates in my garage, but only if I have too.I just want to make sure you don't have 1 first. thers a detail schematic in there somewheree.

theres about a 95% chance it's the switch. usually it's not too big a deal to replace just unplug the 4 wire connector coming from the steering column, tie some wire to it, pop out the switch and pull the wire through, then use the wire to pull the new wires down. sometimes this aproach doesn't work 100% and you have to pull the wheel and some of the stuff under it.
good luck!!

theres about a 95% chance it's the switch. usually it's not too big a deal to replace just unplug the 4 wire connector coming from the steering column, tie some wire to it, pop out the switch and pull the wire through, then use the wire to pull the new wires down. sometimes this aproach doesn't work 100% and you have to pull the wheel and some of the stuff under it.
good luck!!


Is your torque converter locking up like it is supposed too ?? I have had to replace several brake switches and the intial reason for looking at them was do to cruise control not working. It turns out the converter wasn't locking up either and had they did a lot of long highway driving the tranny would have burned up. The brake lights still worked so I never thought it was the switch, But it was.

I,m guessing you dont have a Chilton manual. I can go get mine out of the dust crates in my garage, but only if I have too.I just want to make sure you don't have 1 first. thers a detail schematic in there somewheree.
yup ive got a haynes manual with wiring schematic in it.I just thought i would get some quik insite as to what usually goes on these CC's
Now that i have looked at it,it seems it does not run on vacuum at all.Im i correct?What is going on in the box on the firewall exactly.Is this box a servo or what is it?

Does the year 90 still use a cruise control vacuum servo mounted out on the engine??? If so check it out I would bet its bad

it's computer controlled not vacuum.