I need a chicken switch

[937carrera]

Lots more to read here, including impact from having A/C

http://www.gowesty.com/tech-article-details.php?id=74

Go Westy article - 85 / 95
Brickwerks sell 87 / 93
Wiring diagram 95 / 102

Conflicting information, but a quick look in ETKA shows that the low speed switched on at 87, off at 76, high speed on a 93, off at 82.

Guess who got it right - Brickwerks

Final note; the same source shows that the DF and EY engine codes only have a 2 pin connector so single speed fan and no possibility for chicken switch for high speed.

[bigherb]

interesting the switch temps in Hanynes/ VW diagrams are different to the switch I bought, perhaps there is variation and thats why some peoples fans kick in later?

This from Brickwerks

2 stage fan test by Paul_Barr, on Flickr

You and carrera are confusing the fan switch on and switch off temps on the switch with the high speed fan temp switch on in the diagrams.

[937carrera]

I read the diagram for the switch as saying stage 1 was on at 95c and stage 2 at 102c, nothing about the switch off temps was known (at least by me) until I read ETKA

How should it be read ?

[itchyfeet]

my old switch...

VW rad switch by Paul_Barr, on Flickr

[CovKid]

To be fair itchy, no one is suggesting going smaller to save money. Its just a different way of wiring it. Assuming you do actually understand the principle of relays, the switch side of a relay is very low current indeed - milliamps. Mine isn't wired like that but no reason why it couldn't be. The downside of heavy gauge switches is their physical size and depending on what you buy, may not fit in with say the dash pod. Mine does. So much so, you'd be lucky to even spot it.

As I say, I'm not a big fan of using relays everywhere but sometimes theres no other option - lest you go down the Frankenstein busbar route.

Finally, if the high speed part of the fan isn't operating, its highly likely its the relay above earth crowns. The terminals on that relay socket degrade just as badly as earth crowns do. I must have fixed a dozen T25s with that fault.

[crazyhorse]

IMG_3715 by Crazy Horse, on Flickr

Chicken switch done.

And surprise surprise.... it works.

Thanks Itchy for the instructions.

Did take a while, hardest part was cutting the red/white and red/blue wire tight space in there.

But all good and good insurance policy when the weather gets (if it ever will) warmer

[itchyfeet]

Assuming you do actually understand the principle of relays.

I'm an electrical/electronics engineer...actually

[California Dreamin]

I'm still on the fence regarding the need but if your gonna do it then why cut the wires? I would favour simply baring 1cm of PVC from each wire and soldering the additional switch wires in, finishing with insulating tape. This way the original wires stay in one piece.
Extra connections in a fan circuit (particularly with such high current flow) may cause problems in years to come, keeping the wires intact eliminates and possibility of this happening.

Martin

[itchyfeet]

why cut the wires?

why not ?wire is not sacred, all these vans have been modified, why be precious about a bit of 30 year old wire?

soldering its so 80s there are so many great maintenance free spring loaded connectors available now why solder?