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Tooth Fairy
02-28-2015, 07:03 AM
I cant turn the heater off, how is it controlled?

I took the Sprinter for a run today and couldnt turn the heater off, thank goodness the temperature was only 30C.....lol :rolleyes:.

So.....how is the heater switch controlled, is it electrical or vacuum?

riskydnb
03-01-2015, 07:28 AM
electrical and it has a cable attached to the back of the HVAC panel where the electrical relay resides. Also you may have a broken heater shut off valve which is mounted on the firewall to the right of the blower fan and a bit further back. I would start diagnostics there...You can test the connector for power and ground, if it doesnt have one then your HVAC, relay or fuse is bad. You can also apply 12 volts to the valve and if its working you can hear the valve turn.

Tooth Fairy
03-01-2015, 07:43 AM
I pulled the front panel off the dash today and there is a green wire cable that vanishes into the bowels of the dash somewhere?

I figured it would be easier and cheaper to order a 12v hot water solenoid off ebay, it should arrive next week.
All I have to do is then break into the heater hose and wire it up..

Thanks for the reply..:thumbup:

bc339
03-01-2015, 02:39 PM
I cant turn the heater off, how is it controlled?

I took the Sprinter for a run today and couldnt turn the heater off, thank goodness the temperature was only 30C.....lol :rolleyes:.

So.....how is the heater switch controlled, is it electrical or vacuum?

Depends....the North American Sprinters are an electric PWM controlled design, meaning that it takes a 12 VDC pulsed signal from the ATC (air temp control) to keep it closed with the temp selector on cold. If you have this kind, you can disconnect the connector and check for a 12 V signal at the connector with the key on. The voltage should change when you change the temperature setting.
Other regions of the world may use this type of valve or a cable/mechanical valve. Here's a picture of the electric valve - it's located on the right side of the engine bay.
If you really need to know which one your Sprinter has, you can shoot me your VIN and I can look it up on the MB EPC.

Bruce

Tooth Fairy
03-01-2015, 06:53 PM
Thanks Bruce, but being an ex ambulance and some what modified I cant recall seeing anything like that in the engine bay, Ill take a look after I get home tonight.

Tooth Fairy
03-07-2015, 05:36 AM
I bought and fitted an electric solenoid that is normally closed, you have to add power to open it, so no heat until I want it.
I tapped into where the heater hose comes out of the water pump and up to the heater core.

My boss at work was a service manager at Scania, he said they regularly added just a simple ball valve to the heater system so the driver can turn off the heater.

Some pics of the install.

http://i1255.photobucket.com/albums/hh622/hydraulictoothfairy/Sprinter%20RV%20conversion/IMG_2055_zpsfrllgwio.jpg (http://s1255.photobucket.com/user/hydraulictoothfairy/media/Sprinter%20RV%20conversion/IMG_2055_zpsfrllgwio.jpg.html)

http://i1255.photobucket.com/albums/hh622/hydraulictoothfairy/Sprinter%20RV%20conversion/IMG_2056_zpssnp23nac.jpg (http://s1255.photobucket.com/user/hydraulictoothfairy/media/Sprinter%20RV%20conversion/IMG_2056_zpssnp23nac.jpg.html)

Tooth Fairy
03-09-2015, 02:46 AM
I wouldn't trust that chinese device to be leakproof forever...idk why u didnt try and repair the original its right behind the engine I guarantee u have one

I just went and took a pic, it aint there as I said previously.

http://i1255.photobucket.com/albums/hh622/hydraulictoothfairy/Sprinter%20RV%20conversion/IMG_2066_zpsfzscpv1f.jpg (http://s1255.photobucket.com/user/hydraulictoothfairy/media/Sprinter%20RV%20conversion/IMG_2066_zpsfzscpv1f.jpg.html)