Cruise control no workee

Ram000,

The cruise control holds your throttle open via a cable that connects to the throttle body next to where the gas pedal throttle cable attaches. The other end of that cable connects to the cruise control vacuum diaphragm that is located INSIDE the driver’s side fender well.

Cruise control systems usually have one or two safety cut-offs. The one that is always used is the brake ON/OFF switch that bumps up against the forward edge of the brake pedal lever arm under the dash just above where your foot steps on the brake pedal. Do your brake lights go on and off properly as you step on the brake pedal? If they do, the switch is probably OK. If not, that could be your problem. Some cruise control systems also use a vacuum switch as a backup cruise control cut-off. This switch also bumps against the forward edge of the brake pedal lever arm. (I don’t think our cars use one of these.)

I am not looking in my engine bay right now, but there is a plastic vacuum manifold that mounts to the driver side fender well close to the firewall. This contains a number of connections for engine compartment vacuum hoses. One of them goes from the manifold directly into the driver’s side fender well to the cruise control vacuum diaphragm. The manifold has small letters molded into it that identifies each of the vacuum hoses. Find the one for the cruise control (I think it’s labeled C), pull it off of the vacuum manifold and apply vacuum to it. If you don’t have a vacuum pump just suck on it (no pun intended) and see if it holds a vacuum or not. If it does, you should be able to see your throttle cable move and open your throttle as you apply vacuum. If it doesn’t, your cruise control vacuum diaphragm is probably leaking. If so, that’s a bummer, since it’s inside the fender well. You can get at it, but it requires pulling the left front wheel and removing much of the inside fender well plastic liner.

Check the other electrical stuff first, and hope its something other than the diaphragm.

Hope that helps.
 
thanks for the replies, guys. the car was in a minor front-end collision, but it was enough to pop the air bags. the front end and radiator supports are straight, though. anyhow, the steering wheel is obviously popped and the cruise control button covers are missing, however the switches seem to be intact.

btw, is there an indicator light on the guage cluster that turns on when cruise control is on? if so, it doesn't light up when i push the on button, so maybe this means it isn't getting power, or isn't connected? i'll see what i can do about the vacuum hoses. i've made sure they're all connected, but havnt' checked for leaks. thanks.
 
i was thinking that this problem was more electrical. there arn't any vacuum leaks--i checked w/ a buddy's pump. i've checked the fuses and relays under the hood on the driver's side fender. is there another location for fuses, maybe? under the dash and what not?
 
I've been working around the engine a couple of times and knocked the cruise control cable off the throttle lever. Mine comes off real easy. Was just a matter of reattaching the cable. Probably should put this post in the stupid problems thread.
 
gustang818 said:
I've been working around the engine a couple of times and knocked the cruise control cable off the throttle lever. Mine comes off real easy. Was just a matter of reattaching the cable. Probably should put this post in the stupid problems thread.

hehehe, that was exactly my problem--cable was off and i didn't know it. sorry, shoulda posted here way back when i started this thread that i had fixed it.


on another note, i got those satin-finished cruise control buttons from UPR--very nice pieces! go well w/ the bullitt pedals, lock pins, and trim ring.