So i finally got around to re-installing my a/c unit back into my car today for summer and i got the system charged (did it my self) and the whole thing was running great while filling the a/c lines took it out for a drive and the rpm needle started going crazy, jumping all over the place. The car sounds fine fine but the rpm gauge says its idling at like 200rpm yes, two hundred. when really you can tell the car is idling normal. i think using the a/c fried my my mspnp

its a 93 btw.

i was reading the A/c FAQ but it doesnt seem anyone else is or has had the same problem as me regarding the retarded jumpy rpm readings

the only problem im having that every other a/c using ms owner is having is the stalling of the car at idle and what not.

did i fry my ms?

 

If the car is running, then your MS is fine.

In '93, the tach signal comes from the igniter which is on the left side shock mount. It's a yellow / blue wire that runs both to the tach and to the diagnostic box.

Start tracing.

 

Thanks alot joe!

 

Correction- left side shock mount as viewed from the front bumper looking back. (I normally give directions relative to the driver seated in the car, not sure why I switched up there.)

 

thanks joe i checked the cops wiring harness and seems like the tach wire on coil #3 came out of its socket.

thanks for the guidance joe !