What am I missing? Cruise Control

[amiller360]

In the process of piecing together my cruise control, having trouble getting it to engage. I have an 87 (early model) manual, with an s50.

Things I've replaced:
Actuator
Cruise control brain
Brake and clutch switch

Things I've tested:
pin1 -- Has +12v when power is on
pin2 -- Has +12v until switch is moved to "down" position
pin6 -- Has continuity to plug in back of cluster
pin9 -- Gets +12v when brake is depressed. Has low (not zero) resistance when brake is not depressed.
pin23 -- has good ground
Checked the actuator wire to the throttle body, all good and snug there

I've tried two different cruise brains. Checked grounds, connectors and fuses. It seems super unlikely that I would have gotten two bad brains and two bad actuators. I know my speed output is good because my idle speed is at 800-1000 while rolling and 500-700 when stopped.

I took it to a shop today and they basically told me what I already know and want to charge a ton of money to do what I just did. Is there something that I'm missing or can check? Thanks in advance for any insight.

[estoguy]

Try this article... my buddy, who was the PO of my E30 wrote it.

http://www.e30zone.net/e30zonewiki/index.php/Retrofitting_Cruise_Control

[Das Delfin]

check that it's plugged into the back of the cluster? There should be two little wires connected to the big green plug back there. One is for the cruise and the other for the OBC

[amiller360]

Appreciate the feedback.

I've been using that article to help troubleshoot, it's been really helpful.

The blue/yellow speed sensor wire is definitely plugged into the green block. There is two of them, one going to the cruise brain and the other going to my DME.

[amiller360]

Anyone have any more thoughts? Took the E30 into a shop and he tested just about everything with no avail. They hooked up external power and got the actuator to function. They tested every electrical connection and they seem to be fine. They tested with both computers.

What are the chances that both computers would be bad? Is there anything else that I could be missing?