Couple of radiator fan questions

kmead said:
It is just a ground. A switch can lead to ground for the one or both relays. Multiple grounds can lead to the same point, which one is actually possessing continuity is up to you.
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Goint OT - do you have part numbers for the three wire 22mm base switches for a range of temps? Is there only one? 191959481C with 84/95 and 91/102 values? What about the socket?

EDIT - found a 75/82ºC version 25195948175 - do you have a PN for the socket though?

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kmead said:
It is just a ground.
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Sorry if I'm missing your intent here. The 'two level' (three lead) switch grounds at two different temperatures. So depending which one you choose, that will be the controlling temp for your single fan. And neither temp is ideal on its own, they are intended to work together with two fans or a dual speed fan.
 
lookforjoe said:
Is there only one?
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There are actually quite a few but most of them are only a couple degrees different. I assume it's due to being from different suppliers for different models over the years (the same size switch fits a large range of VW's). Unfortunately I don't have a list of part numbers to offer. The one I typically get is listed for Vanagons in tropical climates.

There must be a part number for the connector socket, but to be honest I usually just go by the type of plug. VW uses one style of plug for many applications so they tend to be readily found by looking for things like "VW 3-wire connector". Then the picture confirms it. But the better approach would be to find the part number. I'll see if I have any cross references to will show it.
 
Dr.Jeff said:
Sorry if I'm missing your intent here. The 'two level' (three lead) switch grounds at two different temperatures. So depending which one you choose, that will be the controlling temp for your single fan. And neither temp is ideal on its own, they are intended to work together with two fans or a dual speed fan.
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Yes I wasn’t clear, the intent is to run two fans. Belt and suspenders because when your belt breaks it is really em-bare-assing when your pants fall down... :)
 
lookforjoe said:
Unfortunately that style /design looks to be to 'recent'
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I might have copied the wrong numbers, sorry. You are right that's a later plug with one end "round". The coolant switch plug looks like this:

cp047177-fan-radiator-temp-engine-wiring-harness-88-92-vw-jetta-golf-gti-mk2-genuine-3.jpg


Tonight when I have more time I'll look again for the P/N's.

In the meantime here is the pin layout:

VWFanThermoSw.jpg
 
I found some info about the 3-pin VW radiator switches and connectors. They were used on many models for many eras. But the style of connector changed at some point, from the "squared off" to the "rounded" shape.

The later Cabriolets (Rabbit convertibles) were among the models from the Mk2 and Mk3 era that had the "squared off" connector like in the pics posted earlier. Here is a chart with some optional temperature ratings for the Cabriolet switches. As you see at the bottom the 88-93 Cabs had it:

Thermostat & Radiator Cooling Fan Thermo Switch
Thermostats & fan switches go hand-in-hand. When replacing one, you should replace the other and both should match temperature-wise (see below). Always, always, always test a new thermostat in a pot of boiling water to ensure that it works before installing it in the car.
thermostats.png

*Notes:
  • An 87° thermostat begins opening when the coolant temperature has reached 87°C and is fully open at 102°C.
  • If wanting to change to a lower-temp thermostat, you must change the thermo switch to a lower temperature version (or vice versa). The low-temp thermostat is 80°C; the matching thermo switch is 85-80°C.
  • Some parts stores incorrectly list the thermo switches as being "with A/C" and "without A/C". From 1980 through 1987, Cabriolets use one-speed fans and use the black 95-84° switch; 1988-1993 Cabriolets use two-speed fans and use the white 95-84/102-91° switch; A/C is irrelevant. See the electrical page for further info.

I'm not certain what year the connector style changed. And there are additional temp rating switches for other models, but off hand I don't know which style connector each one uses.

For the squared off connector (like @lookforjoe needs) the VW part number is 893906231 and the rubber boot is 867972525B . Verify both to be sure. Those part numbers should also lead you to several aftermarket makers, many of which will include the connector and boot together, and some as a "pigtail" (with wires connected). The aftermarket ones are usually a fraction the price compared to the VW items.
 
Now allow me to complicate things further. As I noted earlier, VW used the same size radiator switch (diameter and pitch) for decades on countless models. If you wanted a colder temp one that uses yet another (even newer) style electrical connector, then how about VW P/N: 701.959.481.C. That's what I have on my 1980 (Mk1) "Caddy" with a upgraded performance GTI powertrain, A/C, desert city (stop/go) driving, occasional load carrying pickup truck. Dual range (3-pin), 80/75*- 87/82* C temp switching levels (uses a cold 160* to 170*F T-stat)....I think this is the temps @lookforjoe was asking about. However the connector for this switch looks like this:

tempswitch.jpg


This fits the following vehicles:

Vehicle Fitment: Audi: TT 2000-02 | TT Quattro 2000-02 - Volkswagen: Beetle 1998-01 | Cabrio 1995-02 | Corrado 1994-94 | EuroVan 1995-97 | EuroVan 1999-03 | Golf 1994-01 | Jetta 1994-00 | Passat 1995-97

This is one of the cooler level switches they readily offer (I'm sure there are colder ones but you're not likely to find them easily). And the connector for it is still a relatively current style so easy to find.

At the moment I don't recall which VW rad-switches I bought to use on my X's. I know I chose cooler temp switching levels for use on the Turbo X and Outlaw trackday X projects, but off hand not sure of the specs. I'd have to find them to also see what style electrical connectors they use. But I really don't worry too much about that because all of the connectors are still made by aftermarket companies for little money.

EDIT: Forgot to post the electrical connector for this switch:
www.aliexpress.com

0.52US $ |3 Hole 1h0 973 203 Automotive Electric Wiring Plug Connector Waterproof Cable Socket 1h0973203 For Vw - Connectors - AliExpress

Smarter Shopping, Better Living! Aliexpress.com
www.aliexpress.com www.aliexpress.com
 
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lookforjoe said:
found a 75/82ºC version 25195948175
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I intended to mention, the P/N you show is not quite a correct VAG number. If you drop the last two digits (75) then you have the base number for this type of switch. Typically that base # is followed by a letter that indicates the temperature ranges. In your case they substituted "75" (as in 75 degrees) for the more correct letter (usually "K"). Aftermarket makers often do things like this. But if you search with the base number then you should find several versions of the switch, for different temps. "G" should be the regular (higher temp), and "K" the colder (lower) version. However it will get confusing really quickly because lots of listings are incorrect, makers misuse the identifiers, or specs will vary (i.e. different temps) compared to the OEM VW items. For example 251959481K from Meyle (maker's P/N: 1009597517) has temps of 70/77, 75/82, even cooler than most. Or you might even find the electrical connector listed with that part number (which should be the switch). Remember this stuff has been produced in the billions all over the world for many decades from every part manufacturer out there, so things get mixed up.
 
Thank you for all the research! I've already purchased the Wahler (K) 75/82ºC unit so I went with the aliexpress for the connector - I'm not in a hurry & those include the terminals.
 
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lookforjoe said:
Thank you for all the research! I've already purchased the Wahler 75/82ºC unit so I went with the aliexpress for the connector - I'm not in a hurry & those include the terminals.
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Glad you got it sorted.

This conversation got me thinking about it so I went out to see exactly what I bought for my X projects. Turns out I got one like I have on the VW (later style "box" shape connector, same temps as you posted) and one that is only a single speed (no idea why I got that). So I'll be ordering another two-speed switch and some of the newer style connectors.

Also I just reread my prior posts and noticed a couple minor typos (now corrected). One has to do with the T-stat temperature rating for the these cooler switches. You could use a 160*F to 170*F T-stat, depending on your preferences (earlier I only said 160*). Often the T-stat ratings vary depending on the manufacturer so anything in that range will be fine.

By the way I've noticed all shipping seems to be very delayed lately - especially from China. So it may take a couple weeks to get your connectors.
 
Dewolf said:
www.ebay.com.au

Davies Craig DIGITAL THERMO Thermatic Radiator FAN Controller SWITCH 12v (0444) | eBay

Our very own designed Digital Thermatic Fan Switch Kit can be used with our Thermatic Fans, EWP's and competitors Fans. Davies Craig DIGITAL THERMATIC. Note: if using this switch for use with our EWP's, it will not vary the speed of the pump in response to engine temperature but rather turn the...
www.ebay.com.au
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Is that what you are using? Way too much unneeded complexity, IMO.
 
I have used them in the past on Porsche projects. Very easy to use and work great in our Aussie 40C+ summers. I have however switched to an easier method using a Volvo relay and two speed fans. I wire them to draw current straight from the battery via the relay.
 
I've used that type on a couple of cars. They were easier to add after the fact, rather than rewire things on more complex systems. And they worked fine, allowing you to adjust or fine tune the controlling temp. But if I'm building/rebuilding a new wire harness anyway then a rad mounted thermo switch isn't difficult - especially with a design as simple as the X.


Dewolf said:
Aussie 40C+ summers
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I wish it was that cold here. Add another 5-7 more C's. 🥵
 
Dewolf said:
I have used them in the past on Porsche projects. Very easy to use and work great in our Aussie 40C+ summers. I have however switched to an easier method using a Volvo relay and two speed fans. I wire them to draw current straight from the battery via the relay.
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I'm assuming the standard relay used since the 940 days - Are you grounding 1 & 2 for the fan speeds thru your EMS?

open-uri20140521-562-p5zk1j.
 
Please tell me more about that relay.

But should this jump to another/new thread? Or is it part of the original topic and in the interest of the original poster?
 
Dr.Jeff said:
I wish it was that cold here. Add another 5-7 more C's. 🥵
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Oh Yeh.....we get 45-47 in summer here as well. Week at a time.

I have written about that fan relay somewhere else here.

2nd Radiator Fan Wiring

I hesitate to update, knowing that forum members here seem strongly to prefer doing things the Hard-But-Right way instead of the Easy-But-Wrong way... But there may be a bit of useful info in here for future browsers of this thread. I simply rewired the fans in parallel instead of in series...
xwebforums.com
 
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