98 S-70 w/ 140 K. I recently bought this car. I am having weird problems w/ a/c. My mechanic replaced a high pressure hose & got a/c working. Next day I had no air. Compressor not kicking on. After further testing, mechanic said my ecm was not getting a negative ground which meant the ECM was bad. I can dis-connect my battery & a/c will work normally until i turn car off. It might work upon re-start but percentage of time, it does not. Also, my car is not turning off correctly. Power will turn off,but engine still runs. Again after battery disconnect & reconnect it works for a short period. I have ordered a new switch, but i beleive all of this is going to be tied to the bad ecm. Any thoughts folks?? I have found a used ecm out of Ga for 150.00

 

Find a better mechanic..

 

gee thanks, sir.............

 

You're welcome, and no need to be so formal...

What I'm saying is the diagnosis sounds a bit bogus to me; i.e. like he's trying to cover his tracks. I could be wrong, but at a minimum, I would get a 2nd opinion from a tech who is expert on A/C systems.

BTW: a new A/C switch (in the dash) may just fix it; mine went bad like that...