As far as I know, the SPAL PWM controller is no longer in production due to some issues (hasn't been for about a year or so), but there are some pretty good solid state controllers available as long as you stay away from fans needing more than 30 amps - the HHR fan should be good for the amperage side, but I'd want to check on it's performance in a hot climate like you appear to be living in (see if anyone has good performance with HHR under similar conditions). I was looking in the Speedway Motors catalogue recently and noticed that they had a couple of solid state controllers that looked good in their cooling section. Painless also offers some (both in the over 30 and under 30 amp range - I'm using 30 amps as a separator only because manufacturers appear to have chosen that for their products. There are lots of fans that will give good performance with even the startup spike under 30, and then there are the fans such as those from Ford & Lincoln that need around 75 amps for startup. )

I've seen SPAL PWM for sale, both new & used, but you'll be paying for something with no warranty since the manufacturer no longer supports it.

 

Check with projektdirt, Cory. He did the hhr swap on his 4.7 in Las Vegas, if it worked for him then maybe it was the manufacturer of fan that Steve and I got.

 

Oooh, thats higher than normal!

 

Cory, on his facebook, says he is going to use a different fan, says it doesn't pull nearly enough air.

For these super warm areas the hhr is just not enough. I'm happier with the Taurus fan, of course there's tons of fan options out there and tons of ways to control them, but higher power fans that use the ford fan motor will need extra work to get them powered.

 

To use the Ford or Lincoln fans, you can get off-the-shelf controllers that will work. Most of the ones I've seen are relay based controllers that will cater to the 2 speed versions of these fans, but you need to either make the Hi/Lo/Off selections manually or add a couple of thermal switches to give you the automatic fan speeds you want. I've only seen one solid state programmable PWM controller that's relatively easy to get and will work with the Ford fans and that comes from Painless. If you're handy with electronics, there are many options to build your own in whole or in part. There are quite a few kit bits & pieces that can be put together to give you the type of controller you want. Arduino has quite a few pieces and program elements that can be used to build a custom unit and Cankit has several PWM kits that can be used as a base, adding the level of automation you may want.

Alternatively, you can get fans that can give you enough cfm for a lot fewer amps. A way to go can also include using more than 1 fan. Using 2 "amp lean" fans will allow you to deal with the startup amperage much better, and a pulsed system in control will make the draw even easier. Although I haven't done any research, I would imagine there are quite a few vehicles made these days that use dual fans - although the controller portion would be in the PCM, the fan set would be useable from a junkyard and could be combined with an aftermarket standalone controller. My son's challenger SRT generates a lot of heat and is cooled really well with a dual fan system.