SPAL PWM - Fan Controller

[chuckerants]

According to the Factory Service Manual, my 99's radiator fan is activated by the ECU when the coolant temp is 207F. In my experience with a car that FIed, this is just letting the car get too hot before cooling it back down.

I have a 55mm Koyo as well as having the parallel fan mod. The fan mod DOES work in bringing the coolant temps down much faster once it reaches 207F. However, this STILL didn't address the issue of letting the temps get to 207F initially.

Also, from the factory, only the coolant fan spins when the temp reaches 207F. BOTH fans only turn when the AC is turned on. The fan mod makes sure that whenever the radiator fan is activated, BOTH the rad fan and the AC fans are turning.

With that said, I still needed a way for BOTH the fans to kick on BEFORE getting as hot as 207F.

My research led me to the SPAL PWM fan controller.

What the SPAL does is to have a LOW temp where ONE of the fans turn on at 50%. Then at the HIGH temp, BOTH fans turn at 100%. Out of the box, the unit is set at 160F and 200F - this is where I programmed mine. After test driving it with the AC on, the Autometer gauge never went above (indicated) 195F. Whereas before the SPAL, it would get to 210F (indicated) before bringing the temps back down.

This with closing off the area around the fan/shroud, I should not need a more powerful set of fans like the SPALs.

[chuckerants]

I bought the SPAL PWM and the FRH (needed for controlling an additional fan) on Ebay for less than $150 total IIRC.

Here's one for $140 shipped on EBay. (http://cgi.ebay.com/ebaymotors/SPAL-WIRING-KIT-FOR-DUAL-FANS-PWM-PWM-TS-FRH_W0QQcmdZViewItemQQcategoryZ33600QQihZ020QQitem Z300202389031QQrdZ1QQsspagenameZWDVW)

SPAL PWM Directions (http://www.dewitts.com/download/Fan-PWM.pdf)

Most of the wiring is pretty easy. Here's a couple that is not so easy at least for me:

1. Switched 12v: I used a Mini Add-A-Circuit to tap off the AC fuse in the in-cabin fuse box.

2. AC switched 12v: This is the line that gets power when the AC is activated. I tapped into the AC power wire coming from the AC fan relay.

[chuckerants]

The only other thing you need to know is the Coolant Temp Sensor at the ECU - It is 2E. The SPAL can work with the OEM coolant temp sensor, the SPAL sensor (additional purchase) or an aftermarket (like the Autometer coolant sensor that I have). I thought since I was measuring the coolant temp using an OBD2 reader, I'd just tap off that line.
http://www.fastforwardsuperchargers.com/Install/99-00-ECU-Pins.jpg