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cele0001
08-01-2014, 01:05 AM
Hello everybody.
I recently became a proud owner of 2006 Dodge Sprinter (although it has MErcedes grill). It is a 10 passenger bus so it is technically a true Mercedes (no funny disassemble, assemble business).
It has rear AC/heat with separate compressor and auxiliary heater.
There is switch on the right side of the steering wheel (next to window defrost) that should run the rear cabin heater. There are outlets on the plastic floorboard that runs along the driver's side of the cabin. It is about 4 feet long. (plastic floorboard that is)
There is a timer on the central panel that is suppose to run the espar heater (behind the headlight). There is also a switch on the AC panel (third dial) with squiggly lines that should also run the espar heater (I guess). None of these buttons is doing anything. The squiggly button lights but nothing happens. Timer panel works, it shows time.
Can anybody explain the operation of these things and maybe assist me in troubleshooting the system? A good system diagram picture would be nice.
I have repaired the auxiliary water pump (brushes were stuck) and it now works. I am not getting any response for the switch (two speed blower, has a picture of little fan and a big fan, that is the one next to the defrost switch). However, the switch LEDs work as they should.

Thank you and I appreciate any help that I can get.

autostaretx
08-01-2014, 07:11 AM
If you have the 7 day timer, then the center red button on that little box is what fires up the aux heater.
Push it (squiggley lines appear on display) and wait a few minutes.
You should hear a "click click" sound of the dosing fuel pump, and withing a couple of minutes the heater should fire up and your driver's front wheel well will fill with exhaust.
A properly running aux heater sounds like a jet's APU (muted roar).

In my 2005 it doesn't care what ambient outside temperature is, it simply works.
In the newer (2007+) NCV3 models, it requires ambient temps to be below 40 F.
It will shut down when your coolant reaches 180 F.

Operation of the controls is covered in the Owners Manual, which you can download from http://aie-services-2.net/Sprinter

--dick

cele0001
08-01-2014, 02:30 PM
Is the operation of the rear fan related to the auxiliary heater or should it just work by itself regardless?
According to my research, rear blower motor is only available in conjunction with the auxiliary heater and is controlled by auxiliary (fuel fired) heater control unit which is part of the heater unit itself.
Is the button on the third dial on the AC panel (a booster heater) just a regular PTC electric heater and unrelated to the stationary heater?
I am just trying to understand the system before I go troubleshooting.

cele0001
08-01-2014, 07:05 PM
I have posted this in general discussion but I think it fits better here.

Hello everybody.
I recently became a proud owner of 2006 Dodge Sprinter (although it has MErcedes grill). It is a 10 passenger bus so it is technically a true Mercedes (no funny disassemble, assemble business).
It has rear AC/heat with separate compressor and auxiliary heater.
There is switch on the right side of the steering wheel (next to window defrost) that should run the rear cabin heater. There are outlets on the plastic floorboard that runs along the driver's side of the cabin. It is about 4 feet long. (plastic floorboard that is)
There is a timer on the central panel that is suppose to run the espar heater (behind the headlight). There is also a switch on the AC panel (third dial) with squiggly lines that should also run the espar heater (I guess). None of these buttons is doing anything. The squiggly button lights but nothing happens. Timer panel works, it shows time.
Can anybody explain the operation of these things and maybe assist me in troubleshooting the system? A good system diagram picture would be nice.
I have repaired the auxiliary water pump (brushes were stuck) and it now works. I am not getting any response for the switch (two speed blower, has a picture of little fan and a big fan, that is the one next to the defrost switch). However, the switch LEDs work as they should.

Thank you and I appreciate any help that I can get.

autostaretx
08-02-2014, 02:24 AM
In your other thread, i strongly suggested downloading the owner's manual from http://aie-services-2.net/Sprinter/
It's on page 139 of http://aie-services-2.net/Sprinter/2006_VA_UserManual_Sprinter.pdf
Here's page 137 from my 2005 manual (same text, etc)

61619

If memory serves from another thread a few years back, there's a resistor (to control the fan speed) located in the trough that's under the rear floor... if that area gets overly wet, the resistor and other parts can get severely corroded and/or damaged.

--dick

autostaretx
08-02-2014, 02:37 AM
Now let's look at the wavy line switch and the 7-day timer.
(this is from the pages immediately before the above page)

61620

On my 2005, i do not have the wavy line switch... i only have the 7-day timer.
I've always interpreted the book (and other folks' postings) to mean that you've either got the switch, or you've got the timer. (if you only have the Booster heater, it's controlled by one of the bars across one of the heater control round switch groupings ... see below my sig)

Since my Aux Heater only heats the coolant (i.e. is not a hot air heater) i do not have the (10) knob on the timer face. The Aux heater runs until the coolant reaches 180F, and depends upon the regular heater control knob to control how warm the cabin gets.
(although when the Aux Heater is running, the cabin fan will run at speed 1, even if the regular control's fan speed setting is "off")

If things aren't working: check the fuses on the driver's seat pedestal.
The fuse map is on the plastic door.
Each Sprinter has a unique layout. For example, my Aux Heat pedestal fuses are:
(1) Heater Booster (25 amps)
(2) aux hot air heater (7.5 amps)
(4) heater booster (10 amp)
(11) rear aux heat exchanger (25 amp)

--dick

Booster only switch (not on Sprinters with the Aux Heater):

61621

autostaretx
08-02-2014, 03:23 AM
Finally (?), you can download the entire 2006 (and 2003) Service Manual from http://aie-services-2.net/Sprinter/

On page 8w-42-15 (and beyond) in the 2006 manual is the wiring diagram for the rear heat exchanger.
The front Cabin Heat controller puts its oar in about whether that rear fan runs...
as does a roll-over sensor and some switch from the anti-lock brake system(???)

fun
--dick

cele0001
08-03-2014, 07:36 AM
--dick

Booster only switch (not on Sprinters with the Aux Heater):

61621

See that is my confusion , I have booster switch and 7day timer and two position rear fan switch (the one with one wire of the traction control wired into the circuit) I will take some pictures.

autostaretx
08-03-2014, 08:05 PM
Yes, pictures would help.

As for the booster switch: I went out and looked... i've got the booster bar switch, too
(i just never used it, since it was easier to reach the timer's red button)

I do NOT have the manual Aux Heat switch.
Here's what i have (pardon my dust):
AC panel:
61636

Switch Panel beside shift handle:
61640

Right side of steering wheel:
61639

Left side of steering wheel:
61638

Aux Heater Timer (on switch panel to right of shift handle):
61641

--dick

cele0001
08-04-2014, 05:09 PM
Thank you for the pictures.
I have the exact same setup.
So the booster switch (on the AC panel) and 7 day timer red heater switch should do the same thing?
Can you verify that if you turn the switch for the rear heater blower (right side of the steering wheel) aux heater will also come on?
Thank you for your help.
Esmir

autostaretx
08-05-2014, 01:46 AM
Without running out and testing it, my memory says that the rear heat switch does NOT turn on the Aux Heater.
All it does is turn on the extra circulation pump (so that the rear heat exchanger gets coolant) and turn on the fan at the selected speed.

As for the other switches:
The Boost bar only turns on the burner if the engine is running.
The 7-day timer can turn it on at any time (engine on or off) for a period up to two hours.

added: reading the owner's manual, that rear heat exchanger switch is only described as turning on the fan in the rear.
They also say that that switch only works if the ignition switch is in position 2
Those two items tell me that the rear fan switch does NOT turn on the Aux Heater fuel and fire.
Page 8w-42-17 in the 2006 service manual shows the switch.
The only connection the rear fan switch has to the rest of the heating system is a feed from the 7-day timer ... so if the timer is telling the Aux Heater to run, then you also have rear fan control.

Page 8w-42-15 shows "normal" power to that fan switch being sourced at fuse block #3, running through the contacts of a relay which is pulled in by the cabin heat control panel passing through the rollover detector.

My memory agrees with "if the 7-day timer is running the Aux Heater (engine off), the rear fan can be turned on"
My memory also recalls that that rear heat loop loses more heat through the long hose run than it provides to the cabin. We always turned the rear fan off and just blew the forward fan harder (circa 32 F).

--dick

cele0001
08-05-2014, 10:42 PM
Thank you very much sir. I think with your info I should have enough to get me going (including wiring diagrams).
Currently neither 7 day timer nor booster button are turning on the aux heater. Additionally rear fan switch is not working so I am thinking 7 day timer would be a good place to start.
It is pretty funny that I am looking at fixing aux heater in Florida in August but better now than in January.