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.

[Northern]

is the actuator wire connected inside the actuator?

[amiller360]

Yes. Just went out and disassembled the actuator, pulled on the rubber band (attached to the red gear) and the throttle opened. I was very careful all the pieces inside went back where they were supposed to go.

[Brian697]

Reviving an old thread...

I am having the same problem ('87 325iS with '97 S52) what was your solution?

Thanks.