Good afternoon everyone,

As part of my ongoing series of projects, I decided (for better or worse) to change over to an aluminum radiator from Wizard Rads with two electric fans (primary and auxiliary).

@Greg in France in a post from 2012 identified that connecting the primary fan to the water pump temperature switch was good but resulted in the fan turning on/off frequently. He recommended a MAHLE temperature switch (TSW 7D) that turns on at 90 and off at 85. The problem is, I can't find one that can be shipped to Canada. The one I found is EPS and turns on at 90 but off at 80. Does anyone know the implications of the fan turning off at 80 instead of 85?

Also, for the auxiliary fan. People are mentioning that they wire it into the A/C switch. Can anyone expand on this or have some instructions?

Finally, would the above setup require an alternator with more capacity?

Thanks for any insight.

Stephen.

 

Turning off at 80 will just cause it to run almost all the time, based on your T-stat operating temp.

As far as the on with A/C, you just need to add a simple relay circuit connected to the AC clutch as the signal source IF, the AC comp doesn't run all the time when the car is operating. I have used 105A and 120A alts on other electric fan cars, depending on fuel pump and any EFI amp draw requirements, how many amps do the fans draw? I also like variable speed,, soft start fans, but they are more expensive.

Doug

 

Thanks for the feedback Doug.

The website indicates max draw for the fans is 23.6 amps.

https://wizardcooling.com/i-30503079...577-112hp.html

I’ll check what size alternator is in the car tomorrow, but it will be stock.

 

another alternative to using temp switches is using an updated pressure switch in the compressor. It has three functions, High pressure off, low pressure off(as most work), but then an additonal switch that turn on and off based on pressure (but on the high end). This is connected in series to the electric fan(or relay). I unfortunately didn't learn about this option until after installed my new compressor an filled it and don't want to waste my freon, so I'll wait to install this in the future. I read about this somewhere in this thread I believe. I like this idea as it only turns on when the pressure is higher than normal and stays on until the pressure drops. Which is really what you want. I don't have a part number but its called something to the effect "tri pressure switch" Maybe someone can fill in this void who is more familliar with this setup.

 

You will need a 115 amp alternator. I will be back home in a few days and I think I have there another temp switch I can suggest.
Grant has a paper on how to wire the system up.

 

Thanks Greg.

 

Churmsk,
Here is what I''m using on my S3 lump. Works very well and I use it as a "stand alone" system, not connected to my engine Power Control Module. I believe it can be wired to an A/C system, I just chose not to. I am using an in-hose adapter and 1/4" NPT sender as in this model. Powers two fans, one before the other, and provided "soft start", Hi-Low temp completely adjustable and 30 second run-on after you turn the key off.

Dave

 

My mud map attached.

I run the RH thermo as just that. I use the Factory 85c switch already in the water pump Inlet spout. I also have a switch inside the cabin, that Earths the RH Relay to run the fan constantly. Used it once, more a peace of mind thing.

The LH is purely AC compressor activated. My AC comp is switched indepently of the Internal Climate controls, meaning I can run the inside system WITHOUT the conmp operating, just like an old time heater.

Some claim thermo cycling of the fan with that OE switch, I dont. Greg has the guts on that, when he gets home.

I run a Bosch 115amp Alternator, ex an XJ40 (bucket loads of '40s in the wrecking yards back then),. I have a PDF on that somewhere, and will attach when I find it.

Your 92 MAY have a larger alt, and be driven by a Flat Belt, as apposed to a V Belt.

Alternator PDF found and attached.

 

Really appreciate the info Grant.

I confirmed my alternator is 115amp and runs a flat belt,

I’ll review the attachments and let you know how I make out.

 

Grant,

I always love your PDFs.

SC

 

I try mate, or is it trying, dunno.

 

This one?
https://www.ebay.co.uk/itm/387071297...Bk9SR5zb3v2NZg

 

Looks like a match Greg. It doesn't come up on Ebay.ca (Canada) and it appears that the vendor wants 80 pounds to ship to Canada. I'm going to try looking around a bit more but keep this in mind. Thanks for sending the link!

 

Went to install the radiator and e-fans today (very excited) only to discover that the pulley for the original fan is in the way.

Have to love these tight spaces.

Can others confirm that they had to remove the original pulley system? If so, any great lessons learned? I see that the bolts holding in in place also secure the water pump....

 

The pulley, the belt and the tensioner can all be removed. The fan belt only does the fan.
Where the bolts/studs for the water pump also do the fan pulley casting, either:

• space out the studs
• thread the studs a bit more and use a smaller spacer

I just used large nuts, not pretty but works fine for two decades!

 

Very nice garage, Doug.