Thermo fan replacement

[BlackJKU]

Hi. I need to replace my thermo fan in my 2010 JK 3.8 petrol. Has anyone gone non-genuine and been happy with the result? It seems the factory ones are prone to failure when they constantly get dirt and mud on them.

Any info would be welcome. Thanks, Marek

[Laz]

I've run heaps of14" units from Davies-Craig (Very reliable, just need to upgrade the regular relay to a solid state one from Jaycar)


http://www.daviescraig.com.au/Therma...s-content.aspx



http://www.jaycar.com.au/productView.asp?ID=SY4086


If you setup a push/pull unit then the Push unit (on the outside of the Radiator closest to the front bumper) is very effective at low speed to improve cooling efficiency.

Not sure how reliable any electric fan is compared to a viscous coupling off the motor, they sure don't push the same amount of air.....

IMHO - these are good rules for thermo fans

1) Go BIG (if you can jam a 16" fan, then do it over a 14')
2) Use solid state relays (ok this is just lots of experience with losing regular relays on thermo fans)
3) Install a kill switch for the fans (fans spinning in mud or water don't work very well for very long)

[yetiboy01]

If you want the best get a Spal fan, they flow a lot more air than the equivalent Davis Craig & have a fully sealed motor, no other electric thermometer fan comes close to the performance or reliability of the Spal fans, only down side is they have a premium price

[MightyMouse]

Check the airflow specs VERY carefully on aftermarket fans.... they may be fine for normal use, but struggle when the going gets really tough. Somewhat surprisingly the stock JK Fan blades and shroud are excellent... its just that @#$% stock shitty motor !

After a number of failures with stock fan motors I decided to try a Davis Craig kit as an emergency measure.... was initially quite pleased but the first really high load situation off road and it just couldn't cope. Probably would have struggled on really hot days a well, but never found out.

A bit of a hint as to whats actually required is the 60A fuse in the stock JK fan circuit. The vast majority of the aftermarket ones i checked on were around the 20A mark... obviously a significantly less powerful setup, which raises questions.

Ended up using the adapter kit made by Pops Engineering that allowed me to use an extreme duty SPAL motor with the standard JK blades and shroud... very neat solution. Not cheap overall as the SPAL fan kit is EXPENSIVE.... but that's just what the powerful motor costs so.......

You do need to buy the EXACT SPAL fan kit separately. There is a huge range of SPAL kits... you need the correct one.... cheaper means a less powerful motor The SPAL motor is sealed, fitted with front and rear ball bearings... and when on high just about sucks the vehicle forward

And...... the wiring advice from Laz is excellent for older vehicles or complete replacement of the JK's control system ( no small task )..... BUT with the standard JK control system its not practical as the low speed relay is actually embedded in the TIPM and the high speed relay is installed in a VERY tight location.

Also check the low speed resistor ( its inside the fan plug on the shroud ) isn't cooked. They aren't all that reliable. If its ceramic is cracking off its had a hard life - probably due to the original motor drawing excess current whilst it was on the way out. It also has a "thermal fuse" fitted which has a nasty habit of going open circuit.

Hope this has helped.......

[Laz]

Never used a Spal unit - they looks the good though.

BTW - the push pull setup I used to use was the answer for Track work in a previous car I had - I used two thermo switches one for low temp (88'c) and another for high temp (95'c)

Low temp I ran the push and pull fans in series (so they ran at about 6v)

High temp in parallel

[AussieCJ7]

E series Falcon electric fans push more air than most aftermarket. I had a 14" on the CJ and couldn't cope with the high mount in front took some plastic work but put the falcon fans on and now keeps it almost below op temp. For $60 can not beat them

[Laz]

Originally Posted by AussieCJ7

E series Falcon electric fans push more air than most aftermarket. I had a 14" on the CJ and couldn't cope with the high mount in front took some plastic work but put the falcon fans on and now keeps it almost below op temp. For $60 can not beat them

From a wrecker?