1994 Cruise Control Not Working

[AndrewFL]

Any ideas what could be causing the cruise control to not work??

Andrew

[Marc Haibeck]

Andrew,

The number one cause is a vacuum leak. Make sure there is vacuum to the servo actuator.

The other vacuum hose is for the brake pedal cruise cancel function. A leak in that line will forever cancel a cruise request. Try to draw vacuum on it. It should hold vacuum. Sometimes the pedals rub on the hose and wear a hole in it.

Sometimes the set switch in the turn signal stalk becomes resistive. Try pressing it hard about five times. If the cruise activates, the problem is with the switch.

Check those things first.

[AndrewFL]

Thank you, will dig into it tomorrow.

[scottfab]

Easiest to check is the hose coming from the large cruise control diaphragm just above the battery. Check the hose going to it as it goes down past the battery. The corrosive nature of the battery causes hardening and cracking of the hose right there next to the battery.

If the leak is there, don't just replace the hose. Run the new hose inside 1' of larger diameter hose in the spot it passes by the battery. This provides a degree of isolation.

[AndrewFL]

I checked the two hoses under the dash by the foot feed, they both held about 15-17 pounds vacuum. The hoses near the battery held vacuum as well.

I did however find that the hoses running to the plenum drivers side front were leaking. Could this be the cause of the cruise issue?

While driving, I tried pressing down hard on the cruise switch and I was able to set the cruise twice but it would not set after that.

Is there anyone comfortable with talking to me over the phone? If so please pm me.

Thank you all for you help.

Andrew

[scottfab]

Sure sounds like you have a problem in and around the steering wheel.
There are others that have been in there. I hope they are listening in. I never lean on my steering wheel to get in and out and rarely use the tilt feature so as to hopefully reduce the incident of damage.

[Marc Haibeck]

If the cruise works even once after many presses of the 'Set' button, you have proven that the vacuum connections are good.

Next, I would check the electrical resistance of the push button. It's usually about 2 ohms. That seems like a high resistance for a switch but the cruise will work okay with a 2 ohm switch closure. Over 5 ohms is not so good.

[AndrewFL]

Marc that's a great point, I could not get cruise to work after that drive.

Upon further digging, I found that the small plastic hose that goes from the passenger side of the motor, under the plenum, then runs to the injector wire harness, does not hold vac. However I can't find where that hoses runs to.

Where does the hose go? I tracked it under the plenum towards the firewall, but once it joins the injector wires, I can't follow it an more.

[Marc Haibeck]

The vacuum hose that goes into the fuel injector wiring harness goes to the vacuum actuators for the HVAC inside the car. The tube follows the harness through the firewall and exits under the right hush panel. It has nothing to do with the cruise control.

[GOLDCYLON]

Check the brake switches on top of the brake pedal arm. If they have been moved off center and don't make contact with the brake pedal arm, the cruise control will not set.