Mazda had a recall some time in the '90s which involved adding a small box next to the ECU to keep the fans on for 10 minutes after shutdown if the temperatures were are above a certain level. Does this box work with the PFC?

 

That box is totally independant of the ECU. It simply looks for the fan thermoswitch to be grounded - if it's grounded for more than (I think) 2 minutes, it then will run the fans for 10 minutes after shutdown.

I yanked all that crap out with my fan controller, though .

Anyhow, short answer - yes, it works just fine with the PFC.

Dale

 

Oh - for some reason I though it was attached to one of the ECU lines. Thanks for the info.

 

It doesn't have to work because the PFC won't let things get that hot in the first place.

 

The black unused wire that comes from the wiring loom nearby, is used for the fan mod switch. When the wire is grounded, it acts like the thermoswitch was grounded. This grounding turns the fans on or if already on, it steps the fan speed up one, and is done 2 minuted before shutdown, will start the 10 minute timer after shutdown.

 

Yup - since buying the PFC and setting the fans to come on at 85C I pretty much never see higher, even after some pretty spirited driving. However, once I stop and heatsoak, the temperatures generally go down to 87C or so (from ~110C on reestart) and will not go lower. I was hoping that keeping the fans running for 10 minutes while parked would reduce this heatsoaking. (And I realize that 87C is not exactly bad.)

I guess I misunderstand the operation of this box - it understood that it runs the fans for 10 minutes after shutdown if they were running prior to shutdown.