Cruise Control

[stapletonr]

Hello. Im new here and hope you can help or guide me to the correct place. I have a 92 Ply Grand Voyager. 3.3 V-6, Auto. The cruise control was working fine up till about a month ago. Now it either wont engage or if it does it will only stay that way for 10 or so miles then it will kick out. The fuse is good, I tried to find a vacuum leak under the hood but no luck there. Ive heard of a switch on or near the brake pedal but havent been able to find that either. Any help at all will be greatly appreciated.... Thank You in advance.

[gromittoo]

Originally Posted by stapletonr

Hello. Im new here and hope you can help or guide me to the correct place. I have a 92 Ply Grand Voyager. 3.3 V-6, Auto. The cruise control was working fine up till about a month ago. Now it either wont engage or if it does it will only stay that way for 10 or so miles then it will kick out. The fuse is good, I tried to find a vacuum leak under the hood but no luck there. Ive heard of a switch on or near the brake pedal but havent been able to find that either. Any help at all will be greatly appreciated.... Thank You in advance.

In general, Cruise controls are designed to "fail safe". That means that any wires or hoses that get disconnected will cause the cruise control to kick out. Cruise Controls is also always hooked into the brake lights, so that tapping the brakes will kick it out as well. It is very common for a mis-adjusted brake light switch to cuase your symptoms. It is unlikely that a vacuum leak would allow the cruise to work, and then suddenly kick out. I would focus on the wiring.

Here is the order I would check:
1) Make sure that the brake switch is working properly. Do this by parking someplace dark, and stand outside the drivers door with the door open. Push the brake pedal with your hand until you can see red light from the brake lamps reflected off of something, and let go. Keep pressing and releasing the brake pedal until you get a feeling where the brake light comes on. If the brake light comes on with very little pressure on the pedal (say only a 1/4 inch), or worse, if it stays on after you completly let go, you have found your problem, you need to adjust the pedal switch.

2) If that checks out, it could be any of the wires between your PCM and the Cruise Vacuum actuater unit are loose or frayed.

3) IF those look OK, it might be the "ClockSpring" in your steering wheel. The Clockspring is the spiral of wire inside the sterring wheel that connects the horn, the cruise control switches, and the air bag to the rest of the car. It looks like a clock spring, but it is actually a ribbon of wire. The clockspring shape allows the wires to flex when your turn the steering wheel, without putting all the stress on one spot.

Pray this isn't your problem. Clocksprings are not easy or cheap to change, and you don't want to buy a used one. You also have to be careful not to mess up, or you will set off the air bag. If you also have intermittant problems with the horn, then you probably have a weak spot on your clockspring. If you want to inspect your clockspring be sure to disconnect the battery first, so that you don't accidently set off the airbag.

[stapletonr]

Originally Posted by gromittoo

In general, Cruise controls are designed to "fail safe". That means that any wires or hoses that get disconnected will cause the cruise control to kick out. Cruise Controls is also always hooked into the brake lights, so that tapping the brakes will kick it out as well. It is very common for a mis-adjusted brake light switch to cuase your symptoms. It is unlikely that a vacuum leak would allow the cruise to work, and then suddenly kick out. I would focus on the wiring.

Here is the order I would check:
1) Make sure that the brake switch is working properly. Do this by parking someplace dark, and stand outside the drivers door with the door open. Push the brake pedal with your hand until you can see red light from the brake lamps reflected off of something, and let go. Keep pressing and releasing the brake pedal until you get a feeling where the brake light comes on. If the brake light comes on with very little pressure on the pedal (say only a 1/4 inch), or worse, if it stays on after you completly let go, you have found your problem, you need to adjust the pedal switch.

2) If that checks out, it could be any of the wires between your PCM and the Cruise Vacuum actuater unit are loose or frayed.

3) IF those look OK, it might be the "ClockSpring" in your steering wheel. The Clockspring is the spiral of wire inside the sterring wheel that connects the horn, the cruise control switches, and the air bag to the rest of the car. It looks like a clock spring, but it is actually a ribbon of wire. The clockspring shape allows the wires to flex when your turn the steering wheel, without putting all the stress on one spot.

Pray this isn't your problem. Clocksprings are not easy or cheap to change, and you don't want to buy a used one. You also have to be careful not to mess up, or you will set off the air bag. If you also have intermittant problems with the horn, then you probably have a weak spot on your clockspring. If you want to inspect your clockspring be sure to disconnect the battery first, so that you don't accidently set off the airbag.

Thank you very much for the info. I tried the brakelight switch and drove it a little ways and it seems to work alright now. Am going to take it for a longer freeway drive shortly and see how it works. Will let you know the outcome. Again thanks, this is a great place for diyers and I appreciate it.

[stapletonr]

Thank you so very much. I replaced the brake light switch and thus far have put on 2 300 mile trips with no problems. This is one fix I wont soon forget.