Any suggestions on trouble shooting the cruise control on a 1987 911.

It engages but continues to accelerate until I use the lever to disengage or hit the brake. Don't know where to begin to try to diagnose.

thanks in advance.

 

I have never pulled apart the 911 cruise control before, but I know the actuator is like the 944, so I assume it has a cruise control brain as well. In the 944's the solder joints will go bad causing symptoms such as yours. Usually pulling it out and have a tv repair man or electronics guru resolder the board will fix the problems.

 

Hate to appear stupid, but a bit of a neophyte, how do I locate the "brain" for the cruise control on the 87 911?

Thanks again.

 

My workshop manual says it is below the radio under the dash. It should be a silver box, maybe 6x4x2" or so.

 

Got it. A little challenging to bend the tabs holding the pc board in the case but mission accomplished. The board looks very clean but will examine under a glass for cold spots or voids. Thanks again for your assistance.