Tachometer and Dash Problem (SA22C)
 

Hi, so I recently had an alternator die in my 79 rx7. When it died the tachometer immediately shot to max rpms and all the warning lights came on.

I thought it was just because the alternator failed, so I replaced it. But unfortunately the problem still plagues me.

I checked the fuses, and checked the fusible links with a continuity check and they were all fine.

It almost seems like the electrical system doesn't know the engine is running, as when you turn the key to the on position and the engine is not running the tach will instead show the voltage level of the battery.

Anyone have any ideas on what could be the problem? I would like to avoid having to get the cluster out if possible, as I don't think it's the cluster itself, and I've heard its a pain in the ***.

Thanks in advance.

have you tried taking out the battery for like 30 minutes and reinstalling/starting the car. Maybe you can also recharge the battery and then restart the car.

Considering the car was parked for a while with the battery disconnected I don't think that'll work unfortunately.