Elect. Fan...

you need to put a 30 amp relay in. You power the relay and then it sends power to the switch. Just make sure you put a 30 amp fuze in between the 12v constant and the relay.

And depending upon what fan you use, you might want a 75 amp relay. Some fans eat 30/40 amp SPST/SPDT's like candy.

If you don't have a high current alternator, you can forget about using the fan. The stock 65 amp alternator isn't big enough to run the fan and the rest of the car.

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 $110. 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-$90 See http://www.spalusa.com/fans/automated/accessories/fanpwm.html. Ebay will have the controllers for the $70: 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 current load can burn up the typical cheap automotive switch very quickly. The fan draws 30+amps and you need to use #10 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.



This version of the fan controller will continue to run the fan after the ignition switch is turned off, just like most new cars.

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 probably as good as 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.

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.

The stock aero fox alt was a carryover from the carbed days. The E-fan is one big reason the 94 Mustang started coming with a 3G.

I dont believe Jrichker's post was to be taken literally - a 65 amp can run an E-fan. But you might find you have a dead battery at some point (or 10).

Agreed Hissin, I'm running just a cheapass proform e-fan (which despite being cheap actually works for me quite nice) and my stock alternator and even tho it does run fine you should see the numbers a volt meter puts out if your sittin at idle (especially w/ underdrive pullies) and your e-fan kicks on glad stop lights aren't very long or my battery would be long dead. The 3G is comin soon!

Use a 130 amp alternator from a 94-95 Mustang and check out http://forums.stangnet.com/showthread.php?t=646825 for 3G installation help.

You'll be able to pick up a remanufacured alternator for about $170 with a lifetime limited warranty (AutoZone). Use your old alternator for the core and take $30 off of that for a $140 out the door price. If it ever breaks, take it back with the reciept and get a new one for free.

Don't bother with ebay because even though the price may be lower, you will be out of business waiting on the replacement to get to you. Some companies will ship you a replacement for free, but they are the exception. There is always the possiblity that they may go out of business, leaving you stuck with a broke unit. The big auto parts chains like AutoZone and Advance Auto Parts are going to be around for a long time.

With any reman electrical part, have it throughly tested before you leave the store. DOA parts do happen and some marginal units can slip by the inspection process.