VETJET

Once I set the cruise control the car fluctuates between 7 to 8 mph from what I set. Is the transducer the normal culprit for this type of problem?

Thanks.

Pete79L82

First thing to do is check for any vacumn leaks. Next is lube the speedo cable. (Both from transmission to tranducer and tranducer to speedo head) If neither of them take care of the problem then it would be the tranducer.

Smokehouse69

It seems to be a common problem with late 70's and early 80's GM cruise units. I had two vehicles that did the same thing right out of the show room. I remember taking them back to the dealers several times to get it fixed. After a while I just stopped using the cruise. I wish I could remember what they did to temporarily "cure" the problem.

joeveto

Mine varies with the quality of the speedometer "bob". If the speedometer is relatively calm, and there's no rhyme or reason behind it's behavior, the cruise will work well for a minute or so. If the speedometer is whacked out, bobbing like Ali, then my car takes off like a bat out of hell. The first time it did this, I nearly crapped my pants. I agree with the others. A. This is probably not very fixable, not to what we expect from a cruise control system. B. Start with the easy stuff first, as it's usually cheaper.