Lee and Rum4Mo thank you for your replies.
This thread had given me a push to do some further testing which might be useful for others as well.
To make sure that my blower had a
problem as it hadn't stopped working completely I made a cable which would connect the cigarette lighter to the blower. This way when it stopped working again I could unplug the plug that goes to the blower and provide power with this cable from the cigarette lighter.
Yesterday the blower stopped working again. So I provided power directly from the lighter to the blower. The blower WORKED! I checked with a multimeter if there was power at the plug that goes to the blower and there wasn’t.
Initially I was suspecting that the resistor/thyristor pack was responsible for the
problem so I had replaced it, unfortunately the
problem remained but I had now a second resistor pack which turned out to be very useful as the one on the car has been placed in a spot that it is hard to access.
So I remove the plug that goes to the resistor pack. This plug has six pins but only five cables – three that come from the climatronic and two for the power ( ground and positive)
So I used normal cables to connect the pins from that plug to the second resistor pack that I had! Not all the pins though ONLY those that come from the clima.
On the two pins which are for the power I connected the cables from the cigarette lighter.
I turned the ignition key and blower was WORKING!! and I could control it’s speed from the clima controls like normal!
I check with a mutlimeter the pins on the resistor plug which brings power and I got NO readings! That was my Eureka moment! The
problem is in one of these cables…
I switch the multimeter to continuity put the one probe on the ground pin of the resistor pack plug and the other probe on a metal part and it turned out OK!
At that point I had to stop because I had to catch an appointment. So I connected the resistor plug to the resistor on the car. When I turned on the engine switch the blower started working again which makes me thinking that I need to check the ground cable again.
What I intended to do next time the blower stops working is
1. Unplug the plug that goes to the resistor pack
2 check the continuity with a mutlimeter AGAIN between the ground cable and a metal part of the car
3 check the voltage with a mutlimeter between the positive cable of the plug and a metal part of the car.
4 check the voltage between the ground cable and the positive cable of the resistor plug.
If I get power I need to repeat the procedure next time the blower stops working. If not then from steps 3 and 4 I could tell which cable is responsible for
problem and take it from there.
I will keep you posted when I have futher results.
Hopefully when I track down the source of the
problem other people could check on that directly and won’t have to follow what I did.
P.S. There is one thing that troubles me though... Chris boom had checked the cables that go to the blower and there was no power.
When he provided power to the blower the blower was dead and when he replaced it worked OK.
So I am wondering if the car is checking on the motor and if it gets high resistance it cuts down the power otherwise why wasn't there any power on the cable that goes to the blower???