Cruise control quit working in 1995 Jeep Grand Cherokee. fuses all seem to be fine. also is having trouble shifting gears. it is an automatic, straight V6, with 172,000 miles.
there are a few things that can inhibit the cruise control on a jeep, and the more prevalent one is a vacuum leak in that circuit (hose) that runs off the intake manifold (rearmost one with the check valve in it), which then jogs over to the passenger side of the vehicle, and takes a dive down under the battery tray to the vacuum reservoir. if you are creative about making a plug after pulling the hose off the intake manifold, and then disconnect the tiny hose from the cruise control actuator, also on the passenger side of the engine compartment, and then pull vacuum either with your mouth or a small vacuum pump, then you've proven that this is not the reason the system is not working. Also, if your valve cover rearmost vacuum line to the intake manifold is 'leaky', it will cause this as well as other issues, such as defroster or air conditioning not to blow thru the air vents into the crew cabin, but only onto the windshield defroster vents. if this turns out not to be the problem, and the hose and valve cover fitting are in good shape (the center section of this is plastic and brittle and subject to cracking and breaking, by the way!), it's a good time to start to suspect the brake pedal switch. this switch has contacts that do more than just allow the brake lights to come on, there are cruise control 'inhibit' contacts in this switch as well. and yes, these do tend to go bad. in any case, if the instrument cluster blue light never comes on, it suggests that the system has more than vacuum problems and this brake pedal switch is most likely the cause if there is no other known electrical problem, such as an open circuit for the cruise control. I wish I could offer more, but the liklihood of the actuator being the root cause of this failure, is pretty slim, and there is not much else for you to play with, though there is probably an Engine Control Module possibility here, as a group of five or six Cruise Control wires actually go into that box. In any case, do the vacuum hose and vacuum checks first, then start to think about the 30 dollar switch on the brake pedal.
Mar 09, 2009 |
1995 Jeep Grand Cherokee