Need Cruise Help! (long) (archive)

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Just finished installing a cruise setup for my 745i. It came from a same year ('84) 735i and was working in the parts car. I can't get it to do anything and have run out of my troubleshooting knowledge. Here is how it's wired:

- pin 9 goes to the brake connector (yellow/rd) in the accessory connector (C302) and this same connection connects to a wire going to the actuator. When measured there is voltage on the line (coming from the cruise control) and ground. When the brake pedal is pushed the ground goes away.
- Blue connector added to back of speedometer on pin 2 that says "Tempo" connecting to pin 6 on the cruise brain.
- Pin 3 wired into the neutral-light wire on back of instrument cluster. Picks up 12V when the transmission is switched into Neutral.
- Grounds connected (actuator and control unit) and checked.
- Steering wheel stalk installed and seems to function correctly by measuring voltage/resistance when engaging different functions.
- Actuator seems to work since I can get the clutch to engage by applying 12V on the clutch (white) wire (pin 8 on the cruise control unit) and get the motor to run when applying 12V directly to the blue/wht (pin 25) wire.

Additional wires from actuator wired into control unit (pin 24 and 26) for feedback.

As best as I can tell I've got everything wired correctly. I opened the control box and it's totally clean and dry. I do get power into the unit by checking on the circuit board with a volt meter.

The acutator has a 7 pin connector and the black wire wasn't connected to anything. My diagram shows that this should be pin 13 going into the connector on the control unit and I think it's odd that it wasn't in the connector. I've tried wiring it into pin 13 and it doesn't do any good.

To troubleshoot further I really need to see if the box is getting a good signal from the speedometer. There is voltage (about 4.5 v) on the line but the output is solid state (according to the wiring diagrams). How could I measure such an output?

I'm puzzeled by the black wire coming off the actuator connector and other than that I don't have positive confirmation that the control box is working. I also am not 100% confident on the pin 9 ground through the brake. Could I just ground the pin 9 for testing purposes? Does anyone know how I can put in a signal on pin 6 (speedometer) that would allow me to test the unit without driving?

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