I have been trying to figure out why the cruise control in my '84, that I bought brand new in '84, won't work. It never has since day one. The car only has 6,000 miles on it to date. It has been suggested that I look at the switch that contacts the brake lever to see if it is out of adjustment. when I opened up the under dash panel, I found two switches. Which switch would control the cruise system? There appears to be another hole in the bracket that holds the two switches. Could I be missing a switch? Could someone post a picture of the area containing the switches so I can determine if I am missing anything?

 

Your cruise control switch (at the brake pedal) will be the one that has a vacuum hose going to it.

I have repaired so many cruise control problems due to when the hose that goes to the brake pedal switch for the cruise control is REMOVED from the TRANSDUCER or SERVO. Then I use a vacuum hand pump and check to see if this hose and switch will hold vacuum.

If it does not...either the switch is out of adjustment...or there is a hole in the vacuum hose...or the hose has deteriorated due to being by the battery...and the battery acid has ruined it and made it soft and spongy.

Also...I check to make sure the supply vacuum hose going to the TRANSDUCER or SERVO is also correct. The VACUUM CHECK valve by your wiper motor and or distributor has to be correct also. To check to make sure that you have a good vacuum storage system...either find this check valve...and VERY CAREFULLY remove it and make sure this vale is not leaking and will hold vacuum. This check valve should not be able to allow air to flow freely from both directions. Also another way...is to remove the black plastic storage ball located in front of your drivers front tire...and CAREFULLY remove the hose AFTER you have run the engine...and turned it off...waited for about 1 minute...and then remove this vacuum hose. IF you get a hissing sound when the vacuum hose is being removed...then the check valve is OK.

DUB

 

Thank you DUB for your response. I guess I have some homework to do. Unfortunately it will have to wait till next weekend now. So what you are saying is that there are two switches and the one that has a vacuum line attached to it is the cruise control switch. The reason I ask is because to the left of the two switches is a hole in the bracket that could hold another switch.

 

That extra bracket with the empty hole is for the clutch pedal switch for cars with the 4+3 stick shift trans.

The brake pedal switch (with the hose for the cruise control) is adjustable so the vacuum is released when you press on the brake pedal. If the switch is too close to the brake pedal bracket, the vacuum release function (and the cruise control) will not work.

Do you have the Factory Shop Manuals?

 

I have noticed that when I turn on the cruise control that I can hear a click inside the transducer. Check for that. Ignition must be on...