Problems with Cruise Control - Set switch not working?
 

I'm fixing a few things on my new RX7, and right now I'm finishing up adding cruise control. I've got everything in place and wired correctly (as best as I can tell), but it won't set. I went through the FSM and entered the test mode. All functions are working correctly, except that the "Set" button doesn't seem to work. Also verified this per the FSM with a multimeter.

My question: is this just a bad switch, or could there be a wiring problem that causes this? I had to add some of the wiring as my original harness didn't have the plugs, but everything is in place per the FSM. Car is a 91 coupe with a turbo swap, using all s5 turbo cruise parts.

Finally, I know many people don't feel the need for cruise control. However, I have joint problems which make it difficult to drive long distances and I really want to be able to take the car out on longer drives.

The set button is just a dumb button. What may have happened is the motor controller may have shorted out on you.

Have a look at this write up I made a while back.
https://www.rx7club.com/2nd-generati...epair-1126102/

You can look up the motor controller by number and find the pinout specs so you can check with multimeter. I replaced mine, and it worked for a while, only to find out that the voltage regulators were bad. I have to replace those now too.

A number of years ago, I had a problem with my cruise control where I could not set the speed. There's a push button switch under the dash at the clutch pedal that deactivates cruise when the clutch pedal is depressed. It turned out that the rubber bumper on the clutch pedal had broken off. When the clutch pedal is in the up position, the switch is depressed and cruise is active. There's a rubber bumper on the clutch pedal that pushes the switch in. If this rubber bumper is missing, than the push switch rod just goes through the hole and the cruise cannot be set.

Refer to post #15 in this link: https://www.rx7club.com/3rd-generati...switch-369036/
The switch, shown as 18-660B in the figure, hit a rubber bump stop attached to the pedal. The bump stop is similar to this https://www.atkinsrotary.com/store/8...30-43-029.html. If the bump stop is missing, than the switch is always open resulting in a deactivated cruise control.

Not saying this is your problem, but it's worth checking out.

Rx7 s5 cruise ecu
 

How many regulators were replaced?

i replaced the motor control chip.. it wants to set but it turns off immediately

QUOTE=professionalpyroman;12334447]The set button is just a dumb button. What may have happened is the motor controller may have shorted out on you.

Have a look at this write up I made a while back.
https://www.rx7club.com/2nd-generati...epair-1126102/

You can look up the motor controller by number and find the pinout specs so you can check with multimeter. I replaced mine, and it worked for a while, only to find out that the voltage regulators were bad. I have to replace those now too.[/QUOTE]