Sysgen

The cruise control is not working on my S2 and I've started troubleshooting
what could cause this and I've figured that at the same time I would document what I do.

Here is the unit itself before dissasembly.


I've removed the 4 small hex screws and the larger one on the small arm and pryed the cover open. Inside you will find this when the gears are removed.


To test the unit without opening it you can do the following tests

- Using a 9V battery, momentarily apply a signal between pins 1 and 7, you should ear the motor turn, reverse the polarity and the motor reverses and makes a different sound.
(There is no visual cue to any of this if you have not removed the front cover.)

- Now momentarily apply 9V between pins 5 and 6, under nomal operation you should here a relay click.

- Using a voltmeter you should read around 1.4 ohm between pins 3 and 4

- You should read around 2600 ohm between pins 2 and 3

If you openned the cover and manualy rotate the cam gear the ohms between pins 3 and 4 should range gradually from 1.4 to 2600 ohms.

I'll look at the Cruise Control Servo next since I haven't found anything wrong with this part.

Hope to have helpded someone.

Chris Prack

That is nice work. I have never opened one of those but thrown quite a few away. Track cars done need cruise.

Good info. Thanks for taking the time.

951Tom

I would re-solder all the connections in the computer. That's what fixed mine. I cleaned those curved carbon tracks with electrical cleaner too.

Tom
'87 951

Sysgen

That's my plan next, I'll try to document as I go. I also cleaned those tracks like you say but they were not really dirty, that seal on the cover really does a great job.

Mike C.

Resolder the board and check grounds.