How Do You Control Your Fan?

flex a lite 33054 controller

Triggered from ecu.

You could use a thermostatic switch to trigger ground side of coil on a 5pin relay..

https://www.summitracing.com/parts/...MI-aH_7rOl1wIVCl6GCh3OBQD5EAQYBSABEgJwYfD_BwE


40amp 5pin Bosch relay.

Pin30 fused from accessory
Pin87 out to fan
Pin85 12v fused (use same feed as pin30)
Pin86 to thermo switch

Bosch/tyco 75a relay, $5 switch, 10g wire. 15 years no issues.

Mine is controlled by my MSD Atomic CFI.

Dakota digital controller pac-2750

I also us a Flex a lite 33054

If it's a street driven car, you'll want some kind of automatic controller to handle it for you. Race car, a manual switch is fine.

I've been using the Flex-A-Lite controller for probably the better part of a decade now. The radiator probe approach is highly crude but that stupid thing just works. I keep saying that I'm going to switch to ECU control... Maybe this winter I finally will. ECU control makes for a much tidier install, since you're piggybacking on the EFI sensor that's already in place.

Whatever you do, I recommend a kill switch. It's nice to be able to do stuff under the hood with the engine running or even just with the key in the "ON" position and know that the fan isn't going to kick on and slice your fingers.

Stevenmverrill said:

Wondering how everyone with cooler thurmostats control there fans?

My current idea is to run battery power to the fan with a relay to a manual switch powered from accessory.

Open to ideas what you run and pros and cons.

Thank,

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If you don't have a high current alternator, you can forget about using an electric fan. The stock 65 amp alternator on 86-93 Mustangs isn't big enough to run the fan and the rest of the car. If you have a 94 or later Mustang, the stock 3g alternator should be fine if it is working correctly.

Switching a fan on and off manually is a bad idea. Too many guys have been distracted (hot girl kissing on their neck, too much to drink, dog tired and not thinking clearly) and cooked things because they forgot to flip the switch. An equal number have forgotten to turn the switch off for the same reasons and run down their battery.

The best fan controller available today is a DC Control unit. www.dccontrol.com. Cost is about $???. Be prepared to wait 4 weeks or more to receive your controller once you have sent in your payment. The controllers are custom made in small lots and lead times can stretch out.

Next best is a SPAL controller - $70-$120 See http://www.spalusa.com/store/Main.aspx?html=pwmv3. eBay will have the controllers for a bargain price: do a Google search and see what you find.

At the bottom are the Hayden or Imperial controllers available through Advance Discount Auto Parts and AutoZone. The non adjustable one is about $30 ( Hayden 226206) and the adjustable one is about $60 (Hayden 226204). I recommend you do a Google search on Hayden and the part number for more info.

Do not use a simple on/off switch without using a relay. The high current load can burn up the typical cheap automotive switch very quickly. The fan draws 30 or more amps and you need to use #10 or #8 wire on the fan power and ground wiring.

If you are good with electrical stuff (90% of the people here aren't), build your own controller. The numbers on the diagram (#86, #87, etc) refer to the numbers on the bottom of a typical automotive relay.



Note that the temp sensor in the diagram needs to match the thermostat in your engine. The preferred arrangement is to have it open about 5 degrees above the thermostat.

If you are an experienced electronics tech or electrical engineer, email me and I will send you the prototype drawings of a fan controller that is similar in function to the DC Control unit. It is a build it, troubleshoot it yourself item. I will not build or troubleshoot units, so it is not suitable for anyone who isn't really good with electronics.
See my post at http://www.stangnet.com/mustang-for...-sooo-much-amperage-help.859590/#post-8645840 to get the drawings and full details.

Alternate placement for a temp gauge sender or temp switch/temp sensor for an electric fan. Use the heater feed that comes off the intake manifold. Cut the rubber hose that connects the manifold water feed to the heater and splice in a tee adapter for the temp gauge sender. Be sure to use the same water feed line as the ECT sensor. That way you will get the most accurate temp readings.

Tee adapter info:
Make a pilgrimage to your local hardware or home supply center and get some copper pipe and a tee that fits the temp gauge sender. Solder two pieces of copper pipe onto a copper pipe tee with threads in the tee part. Find the correct brass fitting to match the temp sender threads to the tee fitting.

karthief said:

Cheap don't remember what but I think it's a proform with a built in controller that is set at 200 degrees, it has a manual switch too just in case, also built into the controller. Has not failed me yet but I am going back to clutch fan when I do the head swap.

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Love it! What year car is this, SN95? imp