Cooling Fans and Purge Solenoid Prolem
 

Auto FD story made short:

The engine had problems and the owner tried swapping ECUs and the trans control box. The engine had a water seal failure problem.

After installing a NEW Mazda engine and new harness into the automatic, the engine started effortlessly. But; the fans would run continuously and the purge solenoid would cycle, both with the engine off and key removed with a cold engine.

The 93 manuals show that the fans only get coil control 12V with the key on through a 15 fuse. They do not show the black fan control box.

The 94 manuals show the black box in the functionality view and fan relay control view, but still has the 93 wiring schematic which does not show the box.

I could not find a 95 manual with what I needed.

When I pulled the 15 A fuse and the black box, both problems still happened.
Swapped out the ecu with a another stock and a PFC, problem still there.
Swapped out the auto trans control unit, problem went away!

Mazda's manuals are really very very bad!!!!!!!!!!!

The Fan control module is used with an ECU harness adaptor and a replacement fan harness, which is not reflected in the earlier FSM's as far as I know....it's in one of their TSB's or the recall document, IIRC.

Interesting. It must be some kind of mismatched wiring between years.

A new std and auto wiring harness have the new wiring included for the fan black box and do not require the jumper used with the original harness.