Fan controller needed on an R32/24v

[_leon_ 0]

I'm working out what route I go with the thermostat housing and pipework with a conversion I'm doing, using a Mk5 R32 into a 94 VR. To my knowledge, the VR housing has three sensors, yellow for the clocks, blue for the ECU and a black sensor for the fan controller. However the R32 housing has two spaces, one for a temp sensor, another spare. I've already replaced my stock fans with slim line Spal fans, which come on at one speed only around 100C (which I'd prefer reduced to around 95C personally). My aux pump and fans run when expected on ignition and on after run.

My question is - on moving to an R32 - is it possible

to not use the fan controller, use the r32 housing with the yellow temp sensor in the spare slot to feed the gauges? I'm not sure how the aux pump is controlled on the r32 but assume

it's done by the ecu not the fan controller? Also the fans even now just come

on or off. It's not completely clear to me - so any help would be great if

possible! Hopefully somebody can help! :)

[Toad 0]

Can you not just fit the normal VR thermostat housing, this helps with pipework routing and gives you the 3 sensor locations.

 

The fans should kick in at 95 degrees, have you checked the temperature they kick in with VAG Com? The gauge might not be accurate...

[Toad 0]

Oh, and you can buy adjustable fan controllers which connect to the hoses.

[Kevin Bacon 5]

I'm working out what route I go with the thermostat housing and pipework with a conversion I'm doing, using a Mk5 R32 into a 94 VR. To my knowledge, the VR housing has three sensors, yellow for the clocks, blue for the ECU and a black sensor for the fan controller.

 

Almost mate....

 

Blue - Engine coolant temp for ECU

Black - Fan Speed 3

Yellow - Pins 1 and 2 = Dashboard temp gauge

Yellow - Pins 3 and 4 = Electric water pump control signal

 

However the R32 housing has two spaces, one for a temp sensor, another spare. I've already replaced my stock fans with slim line Spal fans, which come on at one speed only around 100C (which I'd prefer reduced to around 95C personally). My aux pump and fans run when expected on ignition and on after run.

 

Speed 1 from the rad switch should kick in at 95. It could be corroded and getting lazy, try a new switch?

 

My question is - on moving to an R32 - is it possible to not use the fan controller, use the r32 housing with the yellow temp sensor in the spare slot to feed the gauges? I'm not sure how the aux pump is controlled on the r32 but assume

it's done by the ecu not the fan controller? Also the fans even now just come

on or off. It's not completely clear to me - so any help would be great if

possible! Hopefully somebody can help! :)

 

Yep, the ECU switches on the electric pump on MK5 cars so should work in your C if wired up correctly (via a relay) and yep, you need to retain the yellow sensor for your dash gauge.

 

As for the pump control, Mr CrazyDave is working on "Crazy Controller" AFAIK and should be ready in the not too distant future :norty:

[_leon_ 0]

Thanks guys

 

Yeah I can use the VR thermostat and pipework - but I want a layout as per Mk4/5 Golf. And keep as much of the 24v stuff as I can.

 

Good suggestions about checking on VAG-COM and the fan switch.. I'll probably wait till I change the radiator and switch anyway - I've got new ones ready to go in.

 

My fans now only have one speed - which is triggered off the fan switch then - therefore speed 3 will never happen. Is it the fan controller than runs the fans as part of after run (i.e. switching off the engine with a temp reading of over 95C) - along side the aux pump? I wonder if ME7 handles the fans in addition to the aux pump. If it did then I can see a need to keep the fan controller? The R32 housing can take the grey/green temp sensor which replaces the 12v's blue sensor - and the yellow one can be kept to keep the clocks happy.

 

What am I missing - sure theres something!! :) Thanks again

[Toad 0]

My fans now only have one speed - which is triggered off the fan switch then - therefore speed 3 will never happen. Is it the fan controller than runs the fans as part of after run (i.e. switching off the engine with a temp reading of over 95C) - along side the aux pump?

 

Mine would do speed 3 if it ever reached that temp, and does after run fine. I've joined the 3 connections up from the original fan and connected them to the positive side of my fans, and the earth to the earth wires. The fans will turn on in the same way as the originals, except that they only physically turn at 1 speed.

[_leon_ 0]

Yep Tom thats what I meant but didnt explain clearly! So if Speed 3 is activated as such - your fans won't begin spinning faster - they'll already be spinning at their single speed - correct?

[Toad 0]

Yeah, they'll keep going at the same speed.

 

I believe the CFM that the slimline fans produce is similar or greater than normal ones on speed three.

 

I'm going to adust mine, they don't sit close enough to the radiator, due to the way I fitted them. And as Kev has done, fit a nice ring of draught excluder to form a good seal between the radiator and the fans. I think I'm losing some efficiency due to the gap between the fans and radiator.

[_leon_ 0]

Yeah I'll do the same - seems a good idea :)

 

So the fan controller is what switches the fans on during after run? I'm purely trying to see if theres a way to not have it once the 24v is in! I might be way off here - but if the ECU in the Mk5 R32 handles after run with the aux pump, surely the same signal can be used for the fans...? It just depends whether the ECU is limited to activating the aux pump on switching the ignition on, or whether it also activates it on after run.

[Toad 0]

I *believe* that the pump and fans are both controlled through the fan controller. Certainly my pump didn't work when the unit was broken, and it seems that the controller gets feeds from the temp sensors. If the Mk5 ECU bypasses the fan controller, then that sounds the way forward.

[KipVR 1]

I've binned the nasty little fan control unit when moving over to a slimline fan, got in the way of my new airbox position! Yep same signal to control both, using relays of course!

[KipVR 1]

I've binned the nasty little fan control unit when moving over to a slimline fan, got in the way of my new airbox position! Yep same signal to control both, using relays of course!

The pump is there to pump the water round the system when the car is off anyway isn't it?

[Toad 0]

I've binned the nasty little fan control unit when moving over to a slimline fan, got in the way of my new airbox position! Yep same signal to control both, using relays of course!

The pump is there to pump the water round the system when the car is off anyway isn't it?

 

Yeah, to stop hotspots forming in the head.

[_leon_ 0]

I've binned the nasty little fan control unit when moving over to a slimline fan, got in the way of my new airbox position! Yep same signal to control both, using relays of course!

 

I think that answers my question. How have wired in your new fans Kip?

[KipVR 1]

Well i had originally intended to use two fans and wire them up so that one fan was the equivalent of 'speed one' two fans were the equivalent of 'speed two' and just ditch the third speed. However i went up to see Carl (bigpantsbaby on here) who's already done an R32 conversion and he had just the one fan which was infront of the rad instead of behind it.

 

He told me he'd never had a problem with it overheating so I was sold on the idea as it creates so much more room behind the rad for access to bits etc. Buuuuuut the long and short is I haven't actually wired it yet!!! What I'm intending to do is have a couple of relays in the car, one with a resistor so that when it comes on it'll turn the fan slowly, the other running at full pelt, controlled by outputs on the the ECU. I've got a relay bank that houses a few extra relays (ECU, headlights, F pump, widebands, and a few others) inside the car as I really dislike having them outside the car. I've had to do a bit of rewiring so that cables will take the current (headlights!) but I feel it's the better option.

 

The only reason i can think VW put the fan realys outside is beacuse of the ridiculous amount of current draw the old fans have, hence the massive chuunky cable feeding it which you wouldn't want feeding through the car if you could avoid it. If you look at the spal fans, see the pathetic wiring coming off it, and it gives you a fair idea of the difference in current draw!

[Toad 0]

However i went up to see Carl (bigpantsbaby on here) who's already done an R32 conversion and he had just the one fan which was infront of the rad instead of behind it.

 

I've been wondering about turning my brackets from DG around and using push fans. Should all fit, and as you say would give loads of room in the engine bay.

[CrazyDave 0]

Hi Leon, working on something right now that'll cover all the stuff you need to do. Give me a call tomorrow if you want to have a natter.

 

Dave

[KipVR 1]

And me!! I've just checked out your fan controller Dave having just posted what i thought I was going to do you've now got me thinking otherwise! :roll: I like the idea of being able to control the fan speed accurately to maintain a more even temperature, something that I wouldn't be able to do with just the two speeds.

 

Toad, unfortunately you can't turn Dave's fan brackets round the other side, the holes in the front of the rad are different. I ended up doing this....

[Toad 0]

That's a shame! Nevermind, as usual it seems you have a lovely neat solution for yours there! How're the seats going.

[herisites 0]

Leon I can confirm that my fan works without the nasty fan controller, if you are giving your wiring to Vince he will explain everything you need. Also worth noting, I have had to use 3 sensors in my stat housing, the grey R32 one, a standard VAG (got mine for a 1.8T) green one, and then the VR's original yellow one (which I now have working to provide the clocks with the temp). You'll probs need to speak to Vince about just using the 2 as can't remember what the green one's for.

[_leon_ 0]

@Kip - Cheers for the info - can't you use a smaller fan alongside a larger one, rather than just a large single fan? Not much extra cost/effort and its got to be better... The wiring sounds a good move.

 

@Dave - The controller sounds interesting - I'll certainly keep an eye - anything to get rid of it! I'm still keen to find out whether it can be removed completely though.

 

@Rob - interesting, they work on after run too along with the aux pump? Didn't expect that about the coolant sensors - I was under the impression only the r32's would be needed - plus the yellow one for the clocks. Wonder why the extra sensor was required... Something to do with the deletion of the fan controller?

 

This puzzle never bloody ends!

[herisites 0]

Not sure about on after run but when we had the car running getting hot at Stealth the fan came on. I don't think my aux pump works though, think that may have been controlled by the fan controller and we've ditched it, not sure tbh :scratch: Vince is the man who will answer all questions :lol:

[KipVR 1]

That's a shame! Nevermind, as usual it seems you have a lovely neat solution for yours there! How're the seats going.

 

Not very well, the foam i have is too soft, so i've got to order some more. You don't need any foam do you!!

 

rather than just a large single fan?

 

Yeah I wanted them infront of the rad though, there isn't enough room for them both in front. If it comes to it I'll just stick some on the back of the rad too, no problems then! It cooles fine with one fan according to Carl, but I'd like to have a controller to automatically adjust the speed of it to maintain optimum operating temperature, I think that Daves jobbie can do that if I've understood correctly?

[CrazyDave 0]

Hey Kip! The plan is to control the fan speed against temperature and be able to adjust the temperature setpoint. So if you want to hold the engine at 95 degrees, the fans will do everything they can to hold it at that temperature. They will start slowly as the engine temp gets near 95 and then ramp up.

 

You won't be able to set it too low or you'll end up fighting the engine stat.

 

Our brackets will go on the front of the rad, we fitted some today to a Lupo GTI without any problems (the rad is the same as a Corrado VR one, but it's 50mm taller). It does give a load more room in the bay, we'll just have to see how well they survive getting the full brunt of the weather on that side of the rad.

 

Lupo GTI Rad.jpg[/attachment:180rqcr8]

[KipVR 1]

Oh I'm sorry Dave so you can! so I went through all that trouble for nothing, arse! Mind you I couldn't fit a second little fan infront of the Rad without cutting about the slam panel, but I don't think it was anything drastic. Phoning you today about the controller.... :D