Cascade Crew

[alloy]

A Tale of two fans……cooling fans that is……….and 4……yes 4 different fan controls.

A couple of months ago I decided to update my cooling fan control. So……..made up my own custom harness using relays and a 180 deg. Zirgo fan switch. Everything seemed to work ok, except that the fan switch turned on at 223 deg. and didn’t turn off. So, called Zirgo and was told a bad temp switch, and they would send me a new one. This one also turned on at about 220 deg, but didn't turn turn off just like the first one……..for a few weeks that is. Then it quit all together. So, I wired a temporary manual switch.

I did some searching and ordered a Hayden #3651 adjustable fan control from work. I liked the idea of being able to set the fan on temp to whatever I wanted. This switch had a screw in temp probe like the stock fan switch in the right cylinder head. But with headers it’s a real pain to get even a stock type temp switch in the right cylinder head, much less one with wires attached to it. So, did a little looking and discovered I could pull the temperature gauge wire out of the loom on the left side and route it to the right side without cutting or lengthening it. I used some of the stock split type wire loom to route it in. Can’t tell it from stock. This way with the gauge sending switch on the right side makes it much easier to install the new fan-sending unit in the left head since it’s towards the front and not the back above the starter.

Anyway……..remade my harness, moved everything to the left side away from the clutter of the battery and all the wiring around it, and added a Bosch 75 amp relay #0 332 002 156 75 (about $30 delivered) to carry the load to the fans. The Hayden controller only has a 30 amp rating, so to be safe I added the heavy Bosch relay.

Got everything installed and all seemed well……..did the initial test and both fans came on. So……started the car and within 2 minutes the fans came on. Ok, adjusted the pot that is supposed to raise the fan temp setting when turned clockwise. Didn’t do squat. Found out using my Auto X-ray that my fans came on at 93 deg. So I called Imperial (they handle the tech calls for Hayden) and was told I had a bad temp probe and if I cut one of the probe wires the fans should shut off. Well ok, they did. So, bad probe out of the box. This is number 3 that was bad. Since I ordered it from work it has a lifetime warranty on it. I ordered another one and waited for my days off to install it. Got it on yesterday and guess what………fans on at 95 deg. Now I’m pissed royally, and too late to call the tech rep. So, went in had a beer and chilled out.

Today I call the tech rep and read him the riot act. Told him the odds of two probes being bad are extremely slim. So, with no answers he gave me the phone number of the engineer that designed the controller. I called him and described the problem. He told me even though the instruction said to turn the pot clockwise to raise the fan on temp, said to turn it counter clockwise. Sure enough it worked. Fans now on at 184 deg, and off at 170 deg.

I called the engineer back and told him it worked, and then he proceeded to tell me that some of the fan controls were supplied with an adjustment pot that wasn’t to specs. They can go as low as 90 deg turn on, and up to 250 approx. And………they turn the wrong way to raise the temp. The supplier ran out of the correct pots and substituted one not to specs. When Hayden found out, the supplier told them to change the instructions. Hayden said no………and recalled the controls…….except it seems the two I got.

Anyway, after installing four separate fan controls I now have the setup I really like. Turns on in traffic and in a couple of minutes turns back off. Works great, just hated the work it took me to get where I wanted to be.

So………..that’s the tale of the two fans. Damn near as long as War and Peace with all I went through. I hope if any of you are considering installing a fan control you can benefit from the pain I went through.



Bosch Relay