Hi,
I have a1982, 200TD Turbo,

today I installed a new the heater monovalve recoonditinion unit I ordered from Merc Shop.
I am sure it is cutting off the heat when I short the ground side pin to the chassie.

I need to make this ground line myself as I seem to have destroyed the ground path through the automatic climate control unit.

I have read the several informative post on heater control problems/solutions but I still have some questions as the circuit diagram in the Haynes manual doesn't explicitally help me.

My questions are:
1. What ciruit do I need to replace/repair/recondtioning to restore the ground side of the heater control valve? The push button controls still work as I can turn the AC on/off and can regulate the fan speed etc, but only get hot hot air if I don't close the ciruit by shorting the ground side. Also the temperature set control still works as the fan speed increases/decreases as I turn the temperaure control away the present inside temperature.

2. When I do manually shut off the heater vavle and turn on the AC, the air does not seem that cool. I have just had the AC recharged. They put in 2.2lbs of Freon, I think the pressaure was about 2.9. Is this enough freon or is the AC compressor not working well? I read about oil in the compressor. Where is the oil put in?

3. I need to change the lower oil line to the oil cooler. The shop quoated me 4 hours labor, but to me it looks like 1/2 hour job, once the oil is drained. I am thinking of ordering the oil line and changing it myself. Is this advisable?

4. To help with the blow by, I plna to use 15w 50. Is this oil grade OK in warm temperatures?

thanks, this is a great forum I have learnt so much by by readingup on the old posts.

Michael

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New 300TB Turbodiesal Owner
Home Mechanic