I have a 940 with non functioning cruise control. At first I checked the vacuum pipes. Vacuum bellow had pipe and the pipe from pedals were under brake booster, but had no T fitting. Vacuum pump had no pipe at all.
So I got new pipes, and connected them . Vacuum pump to T junction and bellow to other T side and from pedals to other. I also sucked the pump pipe before fitting. Vacuum bellow retracted, and engine speed rised. Also it seemed to keep the pressure, not losing it.
So I go for test drive. Result -> cruise not working. I thought about reading code from the led thing. But the led thing has no B box, only A box. I think that this car is so old that diagnosis for accessories is not present?
After that I took the kickpanel down. I took the cruise control stalk connector open (4 poles), and with beeper tested it. It seems to work. When off, no connection on any 4 poles. When on, 2 of those are crosed. Also, on ignition one of them has 12 V. When pressing set speed, 3 are crossed. So I think cruise stalk is ok.
The main unit is VOLVO 3501472. It has two connectors. 1 with 1 wire and other with 8 wires. For the life of me I could not figure out how the 8 wire connector is supposed to come loose. I did not want to break it. If someone knows how to remove it, please tell me. My idea is that with connector removed, I could somehow test the vacuum pump? it has 3 wires coming from the unit. Of course how to test it, if someone knows that?
Next I thought about the clutch and brake pedal switches, maybe those are at fault. On sidenote, brake pedal has two switches, one for CC and one for brakelights? I took the CC switch connectors from both pedals off and tested them with beeper. Both switches are closed when pedal is not pushed. When pedal is pushed, switch opens. I noted that the brake pedal switch has a wire,about 10 cm with abiko steal connector ( so it has female AND male ports) that is not connected anywhere? Maybe that is the problem then? But I could not found any connector that seemed to be missing? So where that wire should go? Here is and image of the connector. Wire color is Blue Red.
Does anyone here have the correct wiring diagram for -91 940? I found online 1994 diagram , but that has different CC main unit with 12 connectors. So that diagram does not work for me.