Last summer I removed my motor driven fan and installed a 16" Hayden puller fan in the existing shroud. I also used a Hayden 3647 adjustable control to operate the new fan as well as the aux. fan. I installed a couple diodes and wired the aux fan to come on with the the main fan and also to come on alone with the a/c compressor. It all worked great for awhile.

One day a couple of months ago I noticed the temp rising and when I parked the fans didn't come on. I suspected the relay so I bought another at Radio Shack and it didn't help. I did a little trouble shooting and found that the adjustable control had taken a dump. I bought a new one at Pep Boys, $35, and wired it in and all is well.

This Monday morning I went out to the garage and the fans are running. The car had been sitting in the garage all night, the fans were off and the engine was cold when I left it. A little more checking and another bad adjustable control. I called Hayden's help line and told the guy on the phone that I'd had 2 failures in less than a year. I asked him if the engine compartment heat might contribute to the failure. He said no, heat shouldn't affect it and they are made to live in a hot environment. He then suggested I buy another control and give it a try. Fat chance!!

I have used Hayden products in the past and been satisfied with them, but, after these two failures, no more. Failing in the on mode is one thing, but, failing in the off mode can be disastrous.

I went to NAPA and bought a Flex A Lite control, 31147n, and installed it today. We'll see how it works out over time. The Flex A Lite control is made to run the fans without a relay, but, I used one in the circuit to take the strain off of the control. Hopefully it will last more than a couple of months.