Fan Controller

88GThatchback

Founding Member
Jul 8, 2002
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16
Livermore, CA
Does anyone use a Derale fan controller? Summit sells them and it looks ok to me. I want the one with the 3/8" probe that threads into a water jacket. I was wondering if the hole in the back of the intake would be ok for a fan sender? I have heard that it is not as accurate as the front one, but i don't know if it would still work ok? I will be using this with the Ramcharger fan. Heres a link to the Derale site: http://www.derale.com/electricfanaccess.shtml

Thanks,
Clay
 
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i will toss out my two cents, though im not familiar with the controller you are lookin at.
unless it is cheap, i would probably go with the controller Michael Yount uses. it is DCController IIRC. very nice progressive unit.

ok, location for a probe. the rear lower intake port is not as accurate (IIRC, coolant pools more than flows back there, so the coolant's temp there will not be as 'real time' accurate.
however, if you are using an adjustable controller and HAVE to have it there, you could tune the controller to work (get the fan to kick on at a given temp from an aftermarket gauge, and not just setting the rheostat at a given temp, which would likely be off).
some folks have used the stat housing for a sender....i think Michael had a custom port put on his radiator. i think Tom also runs one, and im not sure where he installed his probe.

good luck, Clay.
 
tapping the balnk hole in the stock thermostat housing is a MUCH better place to put the sensor as it has flow across it after the stat opens. I use the Delta control (dccontrol) also and it is a very nice piece.
 
For what it's worth, I used the Flex-a-Lite #31147 adjustable temp control with my new setup this year. I have to say that I was skeptical about the quality of the part, but after having it on the car for a couple of weeks now, I'm more than happy. It keeps the car right at the temp that I want it to be and wasn't very expensive. I think it's really a nice piece. My 2 cents.
 
Just one thought about tapping the hole in the t'stat housing -- it's on the 'cold' side of the t'stat. So if something happens and the t'stat isn't functioning properly or gets stuck closed, temps will continue to rise in the block, but the sensor or switch won't see them. Just something to keep in mind - as Tom suggests, when I was using switches, I mounted one of mine there; mounted the second in the radiator tank just under the big hose from the t'stat housing.
 
What you do Mike is leave the stock or aftermarket temp sensor on the block side and put the controller for the fan on the T-stat housing, so if that happens you'll see it - and if that happens the fan isn't going to help much.
 
I'm with you Tom - agree that the fan won't help if the t'stat's closed. Just didn't want someone to move it there as their only switch/sensor source without understanding all the implications of that location. My coolant gauge is run off the stock location near the #5 runner.
 
88GThatchback said:
I was wondering if the hole in the back of the intake would be ok for a fan sender?

The rear hole in the intake sucks for a temp sensor. I had one there for an aftermarket gauge (to allow the stock gauge to work) and drove around for a while with both temp gauges working. I immediately noticed the aftermarket gauge was reading too cold from the rear hole. I didn't like that so I put the aftermarket sender in the stock location up front, and plugged the back hole. Only then did I realize how slow to respond that rear sender location was. The stock gauge no longer works, but I don't miss it much.

Bottom line: I would not use the rear hole for a temp gauge, much less something much more important, like controlling the cooling fan.
 
jwcma - coolant in the block enters at the front on both sides, travels to the rear on both sides, then up to the heads in the BACK, and travels to the front where it returns to the radiator to be cooled. It picks up most of it's heat in the heads, not the block. When you put the sender at the back, you're sampling coolant that has come out of the radiator (cooler) and hasn't absorbed much heat from the heads yet. That's why the factory puts the gauge sender at the front of the manifold. It's where the coolant temps are the highest.
 
I'm using the Flex-a-lite 31165 Variable Speed Fan Controller. It comes with everything you need and has some nice features and good instructions. Costs about $80 at Jeg's but it's pretty smooth. Comes on with the AC which you must have if you run your AC or the pressures will build astronomically. I also have a small light on the dash to reasure me that's it's all working when it should.

http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=141551&prmenbr=361