Minor Electrical Gremlins Symptoms of Larger Problem?
 

I've got the car back on the road, but now I've been able to find out some other issues. Which could be minor, but I'm concerned they are signs of a larger issue.

The seatbelt chime & light are intermittent as to their function. Sometimes I get the warning beep to buckle, other times I do not. Sometimes I get the flashing light, other times I don't. Sometimes buckling makes the light turn off, most of the time it doesn't. Thank God I've never had it happen where nothing makes the beep go off. Not yet anyways.

I've had the start-start-click issue a number of times the past few days which seems common enough and isn't a concern. What is a concern though is today when trying to start the car I got nothing at all. Like the battery was totally, completely dead. Checked a few things, all looked good, tried again, and car started right up.

Is it looking like I've got some computer issues and should just swap it out entirely? I haven't looked into it yet at all, but is there a body computer separate from the ECU?

The seatbelt chime and light go through CPU #2, and most likely it's an issue with the CPU, probably old/bad solder joints.

The no start is going to be something else, the CPU has nothing to do with that. Like everything went dead when you turned the key? If so, that's usually battery terminals not making a good connection.

Dale

A bad CPU#2 can definitely affect starting issues as this CPU also holds components related to the car's security alarm. Considering the compounding issues mentioned in the onset of your post, I'd recommend replacing the CPU; either through capacitor refurb as some other forum members have done or purchasing a new unit outright (FD01-67-560B).

Note: Sourcing a good, working used unit from Fritz is another avenue.

https://www.rx7club.com/3rd-generati...start-1113092/

^Some additional reference.

Topolino is correct and beat me to the punch. Since you are experiencing issues with the seat belt light & chime and now have a click-click no-start problem that means CPU#2 is Suspect #1!

Reference wiring schematics A-1 & J-4 for specific inputs/outputs.

Cheers,
George

Great info everyone. Appreciate the help.

It sounds like this CPU#2 also controls the Wipers which also do not work (not anywhere near the top of the list of things I've been worried about looking into). So further evidence that this needs replacing.

I'll see if Fritz has anything available and, if not, grab a new one from Mazda. Thanks

Sigma,

Did CPU#2 fix your problems? If not, what was the fix?

Cheers,
George