QuestionQUESTION: Hi Ron,thank you for your prompt and comprehensive reply.To answer a few of your queries,I only have heat in car,temp wheel does not alter temperature,cannot hear flaps opening or closing.Battery on car drains if not in use for a couple of days,battery is perfect.WOULD THIS BE CONNECTED TO MY PROBLEM?Thanks again,Kieran(IRELAND)
ANSWER: Kieran,
I would think your issue is in the modulator, the large device that sits on the fire wall with all the vacuum tubes going to it. Is there any leakage evident around that area?
I would test the valve using the procedure I mentioned, if you can hear it working ( which would be great) then we could turn our attention to the control unit inside the car and vacuum lines. All of this could be vacuum related ( a hose off or broken) but since the modulator controls all of the vacuum routes that has to be ruled out.
Baterry draining probably not related, but could be if modulator valve has failed and is shorted to ground
Sorry but these can be a bugger to figure out.
Hope this helps
Ron
---------- FOLLOW-UP ----------
QUESTION: Hi Ron,I reconnected battery today and noticed a noise coming from this modulator you mention with all the vacuum pipes attached to it.Mine is situated on inner valance pass.side.Heater hoses coming from it.The keys were not in ignition.It ran for about 45 seconds and stopped.Could this be the problem?It looks like a replacement part because jubilee clips are new on heater hoses attached to it.I haven't tried anything else yet.On the positive battery terminal there is a quick release plastic dial to disconnect the battery,I wonder was this fitted because battery was discharging on previous owner?I can't thank you enough Ron.Regards,Kieran
AnswerKieran
I wish this was a simple process, but each component needs to be ruled out as I outlined in the response I gave you. Hopefully the modulator is good, if it looks new then that is a positive because it is a very expensive piece. It could be a simple as the AC & Heater Control Valve; which is a 3-Way Vacuum Check Valve for Climate Control it is usually Yellow or grey or you could have a cracked hose. But you have to rule out each component of the system. Unfortunately this climate control which MB used for several years is a real bear to get right if it starts acting up. I have know folks to sink a lot of money into it , only to find it was a $5.00 sensor. So Check all vacuum lines carefully for cracks, look for disconnected sensors on the engine
Wish I could be of more help
If you have access to an Ohm meter , go through the tests I sent you and let me know what you find
Ron
Follow up - good luck, if you ever come across some used W107 Euro headlamps in good shape and for a good price let me know!!!
