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For some reason, all three vent wheel-controllers (potentiometers) are no longer working. They control the airflow through the dash vents. They all turn but have no affect. This is for a 2009 SL63 (R230).
I’m hoping it’s as simple as a fuse replacement instead of something going wrong in the assembly part # 230-830-08-54. However, I cannot figure out what fuse is over that particular circuit. Everything else works in the assembly but they all have dedicated circuits.
The photo was taken off the internet but shows, exactly, the assembly containing the three vent controllers.
If anyone knows the fuse(s) location(s) or has had this type of issue and how it was resolved I would certainly appreciate your help.
R230 Vent Assembly Part # 230 830 08 54
Update: I had taken some pictures of the assembly when I had it out for part numbers. However, I just noticed some solder joints which appear suspect. Unfortunately, I didn’t get all the joints in the shot but was going for part info. Do they look like the culprit? Fixable or best to get a new assembly?
Last edited by mb_texas; Nov 27, 2022 at 10:18 AM.
Inspect all the solder joints for cracking with a 25x magnifier if you have one (one of the handiest things to have around). I would resolder them all as a matter of course. Dry joints are hardly unknown on this car. I remember reading old posts on this issue.
I resoldered and no luck. I can’t figure out what fuse is over that circuit. All I’ve checked in the engine bay are good. Still need to check all those in the rear pass compartment and trunk.
Just check the continuity between the terminals first - pin to pin that is, where they stick up and through the board, with sharp probes on the top of the component pins, by following the tracks visually. Did you resolder them all properly with new flux? It's not sufficient just to reheat the joints. The old solder should be removed with a solder sucker then resoldered properly. (Not saying this is your issue but they definitely looked like dry joints).
Unfortunately, I just reheated and added a bit of solder. I don’t have a “solder sucker.” I did ohm-test the plug to board connections and verified the cable and connector are okay. I was not able to open up the controller box as the wheel potentiometers are soldered in and capture the circuit board to the controller box.
I do have a clone Xentry/DAS system and all three wheel controllers have a value of 127.5% (valid ranges are 0 to 100) and remain so regardless of position. This leads me to believe something in the assembly has gone wrong. I was able to confirm, through DAS actuations, that all motors / flaps / etc/ are working.
Here’s an after shot of the assembly…
Reworked solder joints Fault codes for vent controller wheels.
Last edited by mb_texas; Nov 29, 2022 at 08:24 AM.
That soldering looks OK. You can check each wheel by putting an Ohm meter across each pot, but unlikely all three would have failed together. Is that PCB double sided? Any dry joints on the other side of the PCB? I'd still be looking for a failed connection somewhere; over the years I've 'fixed' hundreds of things by rocking PCBs in their slots or by cleaning connections or corrosion.
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