Mk1 Golf GTI - Radiator Fan switch issue/questions

Guys,
Couple of months ago I had an issue where water temp was getting higher than normal. Checked the fan switch and it was stuffed. Fitted a new one and all good - car drove in VERY hot temperatures (car is in Sydney and I drove it a little distance when outside temp was 44c !!!).

Anyway this week the same issue came back:

1. Checked water pump working - could see water pumping into the header tank.
2. Checked the thermostat - bottom hose initially cold and then after a little while the bottom pipe got hot.
3. Power coming to the fan switch - and when I jumped the switch - fan came on.

Conclusion - stuffed switch - again!

As luck would have it I bought two of the switches - fitted the 2nd one  - all good - fan now comes on OK.

These are the switches I bought - copy parts from VW Heritage - Operating temp is 95-84 celcius.

https://www.heritagepartscentre.com/uk/191959481b-radiator-fan-switch-including-seal-95-84c-2-terminal.html

1. Anyone had issues with this brand: JP Group?
2. I can see Febi ones - but I don't think they are right as they have a temp range of 90-95c.

Anyone recommend a good unit - what about Wahler - see below. Worry I have is that in a couple of months will have to replace again - which is a PITA!!

https://www.autodoc.co.uk/wahler/1719262


Thanks



 

Did you test the switch prior to putting it in?
Did you flush and Back Flush your cooling system?
Did you replace the t-stat and look at the impeller of the WP?
Is your WP impeller Plastic or Metal?
Did you flush and back flush the Heater Matrix?
Do you have the upper radiator card installed?

I have also done from the OEM radiator Matrix to an all aluminum one off the interweb.  It cools better, as it has a larger core.

You can also install a Direct Fan relay and Switch on your dash to turn it on at any time you want.  Normally in the South here I have driven on 140F degree road temps with not issues when the outside OAT was @ 105
Yes I have a 90ish Cabbies, all have had the WP/t-stat/radiators replaced, and the cooling systems were flushed and backflushed about every 3 years.  All the switches were replaced, as I have a/c I have the 3 prong switch, as well as a Radiator fan relay that is near the battery I also drive Automatics, and I have installed a external oil cooler as the 90 Certs didn't seem to have one installed originally….and I don't like the water cooled ones.  

Prior to me installing my external oil coolers, I noticed that if I was driving in 95f degree roads top up with the a/c on my car would tend to run hotter, and that my oil temp would go above 130-150 degrees.  After installing my external oil cooler my engine temp was about 3/4 and the oil Stayed at about 100 degrees.

Normally if you are driving the car down the road the fans usually don't come on, it is when you are stopped that the temps climb or in traffic as when you need your radiator fan on because of insufficient air flow over the radiator.  The upper Radiator cad prevents the radiator and it's working fan from re-cycling engine compartment air over the Radiator core..Only allowing air flow from the grille.

I always lest any new to me switch in a pot of boiling water with a thermometer in it to verify that it switches on at the proper temp prior to installing it.  I too have gotten bad new parts out of the box..

I usually bought my switches from OEM or the stealerships, but now you have to go aftermarket, and that is really a crapshoot as you have too many made in china… Don't get me started about plastic parts…and china.  

I still hate plastic parts, but thanks Tolusina. | VW Vortex - Volkswagen Forum

Hi Brian,
Thanks for the information.

I did flush the radiator. The water is very clean - there is no crud or clouding. The radiator is reasonably "new" - about 10 years old. Given it gets hot at the bottom and top and when driving keeps the temperature to middle or slightly below on the gauge - I'm confident of the radiator.

I did think about changing the thermostat - but that is also new (changed with the water pump in 2015). Car is a garage queen so since then it has only done about 3,000 miles since 2015 and coolant is regularly changed.

Yes - car does have the cardboard top cover - I have to confess I only fitted that about 2 months ago after reading about it on here - might have been one of your posts! Car does seem to run fractionally cooler.

I should have tested the switch - but given it now works and the fan comes on - the switch is obviously OK. I will monitor going forward - I have ordered another switch from a company called WEHLER - hopefully will be better quality!!

Thanks