jwe320

Ok I have searched for several hours and cant find any help, hopfully someone on here can help. 2003 e320 was driving down hy and accessory belt tensioner failed with ac on. At first I though it was telling me the aux battery was bad and I know it is old and been setting for a year. Than accessory started shutting off so when ac quit blowing cold I didn't think any thing of it. Long story short, lucky I was pulling off HY and noticed power steering not working. Replaced tensioner and belt every thing fine except ac does not blow cold at all. Had codes check and climate control system passed. Also checked system pressure had 75lb on both sides. Checked for power going to compressor and would get 12v for 1 sec then off if i keep probe on wire I get solid 12v after around 5 sec.
I am out of ideas and thinking compressor but dont want to just throw parts at the problem.

Plutoe

Put the gauges back on----on the high side with engine running and both sides set to LO you should have 15-17 bar---1 bar =14.7lbs------you state you have 75 pounds on both sides thats equal to 5.1bar.

Therefore on planet earth you either have very little freon(you have a leak) or the compressor will not make pressure!!

My suggestion is take the car to someone who knows AC---you go bowling!!

jwe320

You are right the compressor wont make pressure. The question is why after a belt came off. Did the sudden loss of the belt cause damage to the compressor?
And by the way I have not had any of my 5 cars in a shop for the last four years. And that includes paint work

Plutoe

Your question is one that no doubt has been asked for thousands of years--why do things break??

I do not have an answer for that question!!

jwe320

Really don't know how to reply. I was driving down HY ac working fine, acc belt came off due to tensioner pulley falling off. Replaced tensioner and belt, back on the road and no ac. Shows no codes, no on or blinking light on ac button. Also from the static pressure reading and the fact they don't change with the motor running and ac blowing tells me the compressor is not working. Before I replace compressor I thought I would see if someone with experance with the w211 might have a suggestion, or a test to verify this is the problem. It this seems strange for a compressor to quite from a belt coming off. I have spent hours looking for information before posting, so this must be something that doesn't happen very often. This is a forum where people come to learn about w211 and work on ther cars. Looking at the amount of posted you have I am sure you have helped a lot of people and i commend you for that. But if you don't have any suggestions or know of anything that might help than why post?

jwe320

I found this and think it might be the problem as I checked power wire going to compressor with test light and get one pulse then it goes out then after about 5 seconds solid. The gauges never change. Have been trying to verify the compressor is bad before replacing. I guess with the compressor turning at hy speed and with a abrupt stop must have damaged the valve. Will post if new compresor fixes the problem. Unless someone has any other idea.


"electronic control valve on the compressor is PWM(Pulse Width Modulation) driven."

pinebaron

Brake??

Plutoe

Thank God someone knows the difference!!