Electric Aux Heater Location

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sword_guy

Member
Joined
Oct 30, 2017
Location
NECT
TDI
2004.5 2.0L Passat Wagon
I've searched around here, googled, and asked in some facebook groups, but I can't seem to find a straight answer. I have a 2004.5 and I'm trying to determine whether it has the electric cabin heater installed. I've looked in the fuse panel, but I don't see any high value fuses (I heard the fuse is 100 amps). Are there other ways to tell?


Where is the heater actually located if it's installed? If there's a fuse I should be looking for, does anyone have a picture? Thanks in advance!
 
imo000

imo000

Top Post Dawg
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Dec 13, 2005
Location
Cambridge
TDI
2009 M-B ML320 Diesel & '05 Passat TDI Manual 5-Speed
Wasn't aware that this was even available for this car. Where did you get your information?
 
2

251

TDI Owner/Operator
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May 11, 2002
Location
NW IN
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2015 Passat TDI SEL
Maybe the OP got wrong information. The NMS Passat TDI (2012-2015) does have an electric auxiliary cabin heater but far as I'm aware earlier Passat TDI's do not have one.
 
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sword_guy

Member
Joined
Oct 30, 2017
Location
NECT
TDI
2004.5 2.0L Passat Wagon
I'm from the US. My particular car doesn't have the heater (based on a VIN lookup), but it was available in that year (probably only in Europe...where the history comes from). I'm also thinking of retrofitting it. I finally got some good information in a facebook group. I wanted to attach a pic of the HVAC system, but I don't seem to have a means to directly insert one. It's asking for a URL.

QuickTD, do you have any more info like wiring, a picture of the fuse/relays, or modes of operation? If I retrofit, I don't know if the car will be equipped to make it work, so I might have to make my own controller.
 
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Uberhare

Uberhare

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Sep 3, 2006
Location
Ontario, Canada
TDI
Too many.
If it wasn't for the seat heaters, I would never have tollerated my B5 TDI for so many years. Even with the front grille cover, new heater core and new t-stat it barely made enough heat below -15 C. If you watched the engine temp it would get down to 70 while cruising at -20. I seem to have fixed the problem with a W8 out front.
 
imo000

imo000

Top Post Dawg
Joined
Dec 13, 2005
Location
Cambridge
TDI
2009 M-B ML320 Diesel & '05 Passat TDI Manual 5-Speed
Uberhare said:
If it wasn't for the seat heaters, I would never have tollerated my B5 TDI for so many years. Even with the front grille cover, new heater core and new t-stat it barely made enough heat below -15 C. If you watched the engine temp it would get down to 70 while cruising at -20. I seem to have fixed the problem with a W8 out front.
Click to expand...

Something must be still wrong with your car. Mine has no issues blasting idiotically hot air from the vents even in -20 and I don't even cover the radiator. Do you have enough air flow through the heater core, mixing doors working as designed?
 
S

sword_guy

Member
Joined
Oct 30, 2017
Location
NECT
TDI
2004.5 2.0L Passat Wagon
QuickTD said:
I have the schematics for the heater for the EDC15P (AWX) audi A4. Passat will be similar. The heater relays are driven by the engine ECU. The north American passat will not be set up to operate the relays as it was only offered with an automatic, which is never offered with the auxiliary electric heater. I assume that due to the heat provided by the auto trans cooler, auxiliary heat was determined to be unnecessary. If your car is manual swapped, you could source a BGW ECU, it would have the necessary outputs to drive the heater relays.

The heater operates similar to the glow plug coolant heater on the mk4 golf/jetta. There are 3 elements, 2 are powered by the "high" relay the third is powered by the low relay. Using different combinations of the 2 relays, 3 stages of heating are provided. All of this is based on coolant temperature.

My A4 is equipped with a European AWX manual trans ECU that has the outputs for auxiliary heating enabled. So its just a matter of wiring it up for me.
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When you say "not set up", do you think the option won't even be in the ECU? It's to my understanding that with the VAG-COM, you can set a bit to enable the system. Most auto manufacturers won't change things like that because it costs extra money to make multiple versions of something. Running with that idea, that's why I think the slots for the relays and fuse will be present, but unused. If I could get a picture of the relay block of a car with the aux heater installed, then I can compare. Finding any pics of that has been super difficult though.
 
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johnboy00

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Jun 15, 2000
Location
Bridgewater,Ma.,USA
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2005 Passat Wagon, 2004 Jetta, 2003 Jetta wagon
Sword_guy, Are you in North East Connecticut? If so, you should be able to feel warm air within a minute or so, and full heat within about 5 minutes. If you are not getting enough heat, you may have a clogged heat exchanger or air in the system preventing coolant flow. This is fairly common with these cars.
 
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sword_guy

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Oct 30, 2017
Location
NECT
TDI
2004.5 2.0L Passat Wagon
I am in Northeastern CT. The heat from the heat exchanger works fine. The engine takes a while to warm up. My 8 minute ride to work is very cold. The engine temp will make it up to the second mark just as I'm getting there. And that's at 20*F and forcing 4th gear to keep RPM up. If I'm on back roads and the engine has warmed up, and I turn the fan on full, the engine temp will start to go down. And before we jump at the thermostat, I already replaced it and confirmed that it's working properly.
 
imo000

imo000

Top Post Dawg
Joined
Dec 13, 2005
Location
Cambridge
TDI
2009 M-B ML320 Diesel & '05 Passat TDI Manual 5-Speed
sword_guy said:
I am in Northeastern CT. The heat from the heat exchanger works fine. The engine takes a while to warm up. My 8 minute ride to work is very cold. The engine temp will make it up to the second mark just as I'm getting there. And that's at 20*F and forcing 4th gear to keep RPM up. If I'm on back roads and the engine has warmed up, and I turn the fan on full, the engine temp will start to go down. And before we jump at the thermostat, I already replaced it and confirmed that it's working properly.
Click to expand...
How did you confirm it?
 
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sword_guy

Member
Joined
Oct 30, 2017
Location
NECT
TDI
2004.5 2.0L Passat Wagon
The engine temp comes up and stabilizes in the middle of the range without the cabin heat turned on. If the thermostat was stuck open, flow through the radiator would keep the temp down regardless of cabin heat on or off (which it was doing before I replaced the thermostat).
 
S

sword_guy

Member
Joined
Oct 30, 2017
Location
NECT
TDI
2004.5 2.0L Passat Wagon
Well crap... Guess I'll need a reader. I know there are bluetooth OBD2 things which will stream data to a phone. Do you have any recommendations on a good one for data streaming?
 
O

owr084

Top Post Dawg
Joined
Oct 20, 2004
Location
Northern Virginia (NoVA)
TDI
Passat GLS, 2005, Stonehenge Gray
sword_guy said:
Well crap... Guess I'll need a reader. I know there are bluetooth OBD2 things which will stream data to a phone. Do you have any recommendations on a good one for data streaming?
Click to expand...
The Torque app is the one most android people use. Get the single people recommend In those forums for the app.
 
PickleRick

PickleRick

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Nov 29, 2017
Location
Greenville sc
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05 GLS BHW sedan 5 speed conversion. BHW Carver SantaCruz in progress
I use an elm blue tooth obd scanner. Its much easier than lugging my lap top inside my car.

I like that i can use it in all my vehicles.

Just dont scan for codes while driving. On some vehicles this kills the engine. Data streaming is ok while driving.
 
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