As of today I have TCO'd following:
Issue... No heat in front or rear cabin.
Vehicle:1994 S-420 MB
1. All fuses verified
2. Flap test good throughout
3. Duo valve checked: hoses warm, valves not cycling with engine running and climate control calling for heat. Pulled connector for DuoValve solenoids. Center of connector has 12.67 volts and both outer connections have ground status (from Climate control or possible short on da wiring, etc) Appears dis is why da solenoids are not cycling...
4. Temperature test es follows:
1 30 C.
2 32 C.
3 8 C.
4 5 C.
5 5 C.
6 94 C.
7 14 bar
8 32 and varies with blower operation (current, etc)
9 60
16 0 not equipped
Work in progress to document any trouble codes on main Climate control (DTC memory)....
Will recheck our Forum after gather DTC code information. Does anyone have any advice or thoughts??
Well following "DTC codes" have shown their faces:
E002 A/C push button control module/ rear A/c control module
E013 Wiring connection to rear A/C pushbutton control module
E025 Left heater Core Temperature sensor short circuit
E075 Coolent circulation pump open or short circuit
E081 Left Duo Valve short circuit
E083 Left Duo Valve open or short circuit
E085 Right Duo Valve short circuit
E087 right Duo Valve open or short circuit
Well, dis es a challenge for Hans and I will keep you enformed of progression. Hans know the duovalve assembly check ok from earlier multiple meter measurements. So Hans will be checking wiring harness and core temp sensor. vas unable to klear DTC errors and check over as validation of actual status, etc, all ar solid faults. Work en progress....
The site alldatadiy.com es vonderful and help much for Hans. Is full of vonderful data to help my S-Klase S-420 140 frame be at the BEST as she should be!
Please reply if you hav any help and advice for Hans! All advice appreciated much!Hans[:D]
Thank you Brett! I have found loose connectors so far and corrected the upper duo valve and circulation pump DTC errors.... now following your advice on the left heater core sensor. Dis alldatadiy is great resource for sure.... Hans
Just an aside Hans. I have run Jims diagnostics and cleared the codes after by following his instructions which I believe you have also used. I will repeat them and include the code clearing method that has worked 3x for me ;
READINGS DTCs
- Set the LEFT TEMPERATURE selector wheel into the RED [red] area.
- Set the RIGHT TEMPERATURE selector wheel into the BLUE [blue] area.
- Turn Ignition to ON.
- Press left [AUTO] button.
- Within 10 seconds, simultaneously press [REST] and [O] buttons until the displays shows permanent stored DTCs in memory per the table below. Press the RIGHT [AUTO] button until all stored DTCs are displayed. Record each as they are displayed.
** To delete stored DTCs, repeat the first five (5) steps, then press the LEFT [AUTO] for the letter 'D' (delete) to appear in the window. By pressing the right [AUTO] the display code will be deleted from memory. Continue to press the left and right [AUTO] buttons until all codes are deleted from memory. The display will show 'E0 00'.
- Return the temperature selector to normal setting.
I had a bunch of codes including the EO 75. I no longer have a problem with my HVAc system as mine was an air conditioing issue.
Also the code 16 reading of 0 means you have no rear heater. The rear heater came in the 500 and 600 and by special order. Therefore the loose connecting wires may not be meant to be connected to anything?
Brett would know better if they could be causing a problem any way. Dont want to see you wasting time on something that is not broken.
Good Luck clearing codes, sometimes you have to try more than once!
Peter
Brett got with me and it appears mine is dis solenoid en da DuoValve assemble. I will attempt the 1050 winding replacement and if I do not go blind rewinding the solenoid I will be back to all with a warm cab. Wish Hans luck... H
Finally got around to removing da Duovalve and disassemble same. One of two solenoids es shorted and da bobbin crumbled due to heat... have decided to rewind both to match empedance an operation du to cycle of climate control, etc.. Work en progess to hav a new bobbin fabricated. Am having several fabricated due to having extra HML 28 ga wire purchased. Will have several wound and ready should anyone hav need en da future! Both old valves are en poor shape and will require a gut soak en lubricant and possible spring replacement. da circulation pump is en gut shape though... thank da Gods. More to come when new bobbens received an or found! hans
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1994 Mercedes W-140 A Lifestyle of Dutchland Excellence.... S-Klasse
Linear Mode
