Aircon Thermo Fans

[Superhux]

Hi Guys,

I was just wondering... My car overheated the other day and the only thing I can think that caused it was the fact that the aircon thermo fans didn't kick in.... Is there a way to test them or trick them into turning on???

Love to here from anyone with past experience....

Thanks heap

Hux
300tdi
1997 s/wagon
310,000 kms

[87County]

If you look over the fuse connections and test with a probe test light you will see that the fan wiring is linked from the a/c switch - therefore if the ign is "on" and if the switch for the a/c is "on" the fan wiring should be live and the condensor fan(s) should run.


Check the connectors and the fuse...

Connectors vibrate and wiring deteriorates over time.


There are many other causes of overheating.

[Superhux]

Thanks heaps... Do you think the thermo fans not working with the AC on, on a hot day would cause ol' Landy to overheat????

[87County]

Thanks heaps... Do you think the thermo fans not working with the AC on, on a hot day would cause ol' Landy to overheat????


maybe/perhaps (depending on the condition of your radiator and cooling system) ... but why is the condensor fan not working ?

[Blknight.aus]

nope, overheating from failed AC fans usually only occurs with the AC on
if

you spend lots of time at idle
you spend lots of time at low speed
your VC is shot
your fan is shot
you have other cooling issues
you have electric fans fitted that are too small (flow rate/diameter/both)
you dont have your shroud fitted.

[Superhux]

Thanks for the info.... In relation i have now got test the thermo switch on the thermo stat housing... the inner one is for the temp gauge the outer i have found is for the fan sensor???

PS How do I test a viscous coupler?

Cheers,

Again thanks heaps for all the info.

[Superhux]

Is anyone able to tell me how to override any sensors to the thermo fans... I cant find a connector anywhere...

Cheers,

Dave

[Jonesy1972]

If you are looking at replacing the thermo fans, I found some generic fans in an auto parts magazine for $20 each. If you are interested I send me a message and I will try and find more detail for you.

Regards
Jonesy

[TheEntertainer]

Hi mate, not sure if this may help but you can use the madman ems engine monitoring system to trigger a kenlow fan at a pre set temperature. This may assist in keeping your engine a little cooler.

[stumps]

Superhux,
My fans didn't work a while ago either when I first got my D1. I metered the circuit/relays etc all the way through to find that both fans were cactus...wish I had started that end first. Then, reading through the forums here it seems this is quite often the story if they get mud/crud/submerged etc, so would test the fans first if you can easily direct connect to battery etc.
I ended up getting a pair of replacement 2nd handers for not alot of $$. For some reason new ones appear to be priced similar to gold!

[chazza]

I replaced one of mine with a Davies Craig fan for about a $100 and some minor bracketry that I made.

To test them: turn the air-conditioner switch on with the ignition on; if they don't run, test for current at the first connector downstream from the fan; or probe the wire with a test light and the earth clip properly earthed,

Cheers Charlie

[Superhux]

That would be awesome...

[Superhux]

Hi Stumps,

Can you please take a photo of the relay location?? I Have tested power at the connector, and found that there is no power here however there is power at the fuse :( so something says that these are not connecting at the relay... I have looked at the RAVES ebook and it shows me a photo of a K109 relay but it doesnt appear to be there in my car ???

Thanks heaps Dave

[Superhux]

Hi Jonesy,

If you could point me in the right direction just in case that would be great...

Cheers,
Dave

[stumps]

Oh sorry mate, did not see post...yes will get a pic in next day or so.



Hi Stumps,

Can you please take a photo of the relay location?? I Have tested power at the connector, and found that there is no power here however there is power at the fuse :( so something says that these are not connecting at the relay... I have looked at the RAVES ebook and it shows me a photo of a K109 relay but it doesnt appear to be there in my car ???

Thanks heaps Dave

[stumps]

Oh sorry mate, did not see post...yes will get a pic in next day or so.

Dave, Here is pic of K109 (screwdriver tip on it). On my 97 Disco TDI it is below glovebox, accessed by removing cover, then 13 mm nut to open down the relay tray.