Climatronic idea - what do you think?

[graeme86]

I was sitting in a new BMW 135i Coupe the other day which is fitted with that regenerative braking system. BMW seem to have the confidence that the battery won't go as flat as soon because of this, so you can sit in the car with the ignition off and still have the ventilation fans running.

I was kind of impressed by this feature, seeing as it gets quite hot over here sometimes.

Now, on the VW Climatronic is an input so you can plug in the Standheizung, so it powers up the Climatronic headunit and servo motors when its on.

See this post:
http://forums.tdiclub.com/showpost.php?p=1567537&postcount=52

So I'm thinking, if you add an input, say from the key sensor wire, to power up the unit, and add the switching relay as well (just using a VW Relay #79) to directly power the fans (as described in the linked post), then you could power up the fans when the ignition is off as well in the VW.

I think the key sensor would work well as the source signal because you would normmally be in the car at this time with the key in ignition, so once you pull out the key and get out of the car the fans would stop (saving the battery)

Its only set up to cool you if you are in the car so to speak, not to supply extra ventilation if the car is just parked ( that's for the solar sunroof to do )

Any thoughts/feedback on this idea?

Graeme

 

[graeme86]

Bump for any new inspiration.

 

[glitdi]

Graeme dont know if this helps or not. Are you aware that some of the Touareg models have an option very similar to this.. You can hit the button on the dash and run heat with vehicle shut off. Would be a good source for your modification as a basis for wiriing and programming and I believe if I remember from memory the switch is rectangular style that fits into the dash. Or its built into the climatronic controls. I dont think it uses the auxilary heater. (that little heater with the funny name I forget right now that costs thousands of dollars to install. ) I believe it takes the heat from the heater core and is uses residual heat and turns off after 30 mins.
The only problem is if you want ac it runs directly off of the engine, so you could use the fan only but it might be able to leach off of the residual cold from the ac condenser for minutes. Hopefully this helps its late and I am tired.

 

[graeme86]

Are you talking about the 7P Touareg "REST" Function?

http://my.vw.com/2012-touareg/comfort/climatronic-heating-cooling

 

[glitdi]

Thats the one! its available on the older mark 1 generation which I believe is closer as far a programming than the mark II or ar the 2012 III..

 

[graeme86]

Yes, thank you very much.

I just found a pic of the 7L unit as well.

Will investigate further

 

[Nash_TDI]

I was researching adding the solar sunroof to my car. I thought its purpose was like a battery tender. But after looking into it it vents during hot days and turns the fans on. I think I would also have to upgrade to climatronic at the same time though.

 

[graeme86]

Actually, no.

The solar roof also works with the manual air con.

It just powers up the fan motor to blow air through whichever vents are left open (same as the climatronic setup basically anyway)

 

[graeme86]

I found a copy of VW Self Study Program #154 which explains a kind of REST function on 3A Passat Taxis.

http://www.volkspage.net/technik/ssp/ssp/SSP_154.PDF

This included a control module and dash switch plus an additional electric water pump to move the coolant around when engine was off.

 

[glitdi]

Great!
Looks like your on your way..

 

[graeme86]

...except the switch and module are both obsolete now.

I have worked out a circuit and will post up shortly.

Relatively easy to install - just need to divert the main fan power feed from the T17a Climatronic harness plug through the relay and back to the plug where everything else in the climatronic harness stays the same.

Then you just need to add the "D1" connection to get the HE display with the ignition off and power up the unit (controlled by a switch to activate the function)...

Will be using this OEM switch I found:

On my R32, there is already a ten minute timer controlling an auxiliary electric coolant circulation pump which comes on as soon as you switch off the ignition (not temperature controlled either - just comes on no matter what)

So if I switch off ignition and want to keep fan/heater going, I just need to press this switch (the coolant pump is working anyway in this case).

I mainly want this feature to just keep the vent fans going anyway on a hot day.

I sometimes switch off the engine at long red lights etc.

Any on/off switch would work - the switch just activates a changeover relay for the main fan feed to work with ignition off.

 

[glitdi]

I dont want to know how much that switch cost you...hopefully not to ridicoulous..

 

[graeme86]

Yes...this switch was ridculously priced - plus I also had to buy another ridculously priced Audi TT 8N switch console to get the inner workings out of their alarm switch (to change the internal circuitry of the fan switch to something more suitable).

The Passat 3A switch looked a lot like a demister switch, so would be a lot easier to use another one of those in the mk IV, either in a blank space or in the optional additional switch mount for the kick panel.

 

[dremd]

Subscribed:
Any way I can just get an email every time Grame86 starts a thread?

 

[graeme86]

Here is a link to schematic using the above modified Audi Fan Switch:

http://www.users.on.net/~graeme86/clima/REST%20Function%20Schematic.JPG

This will switch on the HE function using my modified Audi Fan switch (with Audi TT alarm disable switch internals..to get separate telltale)

This uses the ten minute timer built into VR6 for electric water pump that runs for ten minutes whenever you switch off ignition..so REST will automatically switch off after 10 minutes maximum.

If you do not have a water pump with timer you can use an Audi relay 1J0 959 485 A that has the timer in it instead (i have a schematic for that too but untested WITH AN ACTUAL RELAY yet)

It seems this timer relay is used for different functions and if you connect different pins it runs with either ignition ON for 10 minutes or if wired differently it on runs when ignition is cut OFF for ten minutes.

New VWs like Touareg etc actually have a REST button on the climatronic face itself and it functions for 30 minutes.

Using water pump will keep coolant heat circulating in system. I mainly want it for our summer days to get fan function when parked (wont be any chilled air of course!)

Basically you unplug the existing fan feed to the T17a/1 plug and divert it to a new relay, then the new wire comes back and plugs into the T17a/1 plug.

Then also need to run the new wire to D1 pin.

That is the only modification to the climatronic harness

In my case I also need to tap the signal wire for the aux. water pump to obtain a ten minute feed.

Then you need a new high current fuse for the fan feed when ignition is off - the rest of wiring is self explanatory on diagram.

With this setup you can actually switch on and run the system and lock the car to pop into the shops etc and still vent/heat car (car is locked and swithced off of course).

If you tap into the central locking feed for example, it will all turrn off when you lock car. (I was looking for a feed that would go off at some point to turn off the system in case it was left on accidently and this was my first thought)

A normal switch would work to switch on system - this schematic using a momentary action OEM switch and the latching 434 relay, which will also unlatch when the water pump feed stops working.

See my Webspace page for details of this relay:

http://www.users.on.net/~graeme86/relays/relays.html