Hi,

I have the dreaded A/C issue where one side of the car (passenger) is getting the right temp air from the outlets, but the other (driver's) is hot all the time, regardless of the temp setting on the CCM.

I have read most of the advice from the various threads on the problem, and have done the following to no effect:

• Replaced the DCCV for a brand new one
• Checked the CCM for burnt tracks (none) and broken MOSFETs (none)
• Checked all three thermisitors in the heater box, and all of them read 26-27KOhms at ambient temp
• Cleaned the cabin air temp sensor that is in the dashboard

I'm now left (I think) with the last thing to check, which is the wiring to the DCCV.

When I replaced the DCCV (what a faff - I have a 2.7d, and you *have* to do it from the bottom, after wrestling the radiator shield out the way as all the retaining clips have corroded and stuck themselves to the torx fasteners making removal impossible), the wiring to the valve looks ok - visually, at least.

So I need to electrically check the wiring - but I'm guessing, knowing my luck, that if there is a break in the cable it's not going to be in the first couple of inches of cable behind the bumper.

Can anyone tell me where this wiring runs? And is there a common point where it may have broken during to rubbing / chaffing? I can see the three wires as they disapear up into the engine bay, but can't see where it runs to from there.

And if it isn't this, and keeping in mind everything I've done so far, is there anything else I can check?

Thanks

Jason

 

I know you are not asking about your 1986 BMW 3-Series that you have under your screen name. Please provide us with what year car and model you are asking for information on. We are good but not that good!

 

2.7D, which is in my sig... And I do mention it in the post...

 

The wiring is behind the front bumper and also behind the front wheel fender well plastic shields. It's not common but has been reported and it's always behind the front bumper cover.

Before you go to all that trouble follow up on your idea to check for power and ground at the electrical plug. Report back what you find.

If you need the A/C clamp off all three hoses going into the heater for a temporary fix.

DCCV's have been bad right out of the box. Did you measure the new DCCV and compare it to the old DCCV?

Also the CCM (You don’t have NAV, Correct?) might not show a burned trace. Any chance you can swap one just to check? If not mark the CCM as probably OK but not 100% sure.
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Well I am glad you added "2005 S-Type" to your signature. It will help!