[JustJeff]

Originally Posted by Pete_89T2

Found this Taurus e-fan wiring diagram with a little googling on a DSM forum



If this diagram is correct, the fan body provides the ground (-) return, and there are 2 other wires - a high & low speed (+). Here it's rigged up so that whenever the switched +12V is on, and the "temp probe switch" is closed, the fan runs at low speed, and when the "AC Clutch wire" is providing +12V, that 2nd relay switches the fan to high speed. Note also they mention the high current draw when the fan starts up on high, and they recommend using a 75A relay, and the fuse to the battery is a 50-70A, and "normal" current draw on high speed is ~34A! Sounds like an alternator upgrade will be in order if you still have a stock FC alternator in there.

I've got a modded S5 alt (140amps). Looks like the diagram you provided works off of one temp switch, but both high and low are wired into the diagram.

I'm content using either high or low. I don't really want to mess around with finding a location for a second temp switch. Is the diagram I was using ok, provided I have correct wires for ground, low+, and high+?

Originally Posted by RETed

I just want to comment on the current draw #'s...

Holy soda crackers Batman!
Trying to find a 75A+ relay is encroaching on the realm of "soleniods."
It's going to be difficult to find a quality relay rated that high from most common electronics parts vendors.
If you do find one, I'd bet it'll be pretty expensive too?

I was looking around for a 50A rated relay recently, and I ended up with an NTE one (Made in China) for about $10.

34A of current is a lot of juice for a single fan.
I'm sure there's other, aftermarket fans that'll run almost the same airflow for less current - i.e. more efficient.
We're talking minimum wire thickness at least 10AWG...8AWG?
Of course, you can't beat the price of a used fan...
But it looks at this point that the fan is faulty, so gambling with used equipment comes into play now.


-Ted

I had the same problem finding a 50A relay. No one in town has one... I'm using a 40A relay now..which I thought would be ok. I got annoyed and put 10AWG wiring all around for the fan, relay, manual switch.

I don't know that the fan is faulty. I was playing around with both my fans today (mounted and spare). They both behave the same way. They both pull air on low and push air on high. That leads me to believe that the problem is not the fans...but user error instead.