e36M42 DME error 1.7.2 in e30: error code 85

[selespeed]

This is regarding my e30 A/C.

i have this error code 85 in my DME constantly. It's been more than 2 years since this error remains in DME memory and resetting doesn't make it go away. I don't know what the mechanic did to my a/c. i would like to have this error removed entirely. but the mechanic is not willing to tell me how to do it nor is he willing to do this I did this in another city that is far away. I believe he did some illegal short cut resulting in this error!
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Details of error on diagnostics says that:
- no increase in idle speed even thought air conditioning compressor is running
- open circuit at pin 86 od DME control unit
- short circuit to battery positive at pin 85 of the DNME control unit

Fault Information
Air Conditioning = ON
If not ok: check wire to DME control unit pin 85
Set temperature control wheels to WARM and switch off defroster, recirculated air or air conditioning switch.
Compressor Normal value = OFF

Air Conditioning Compressor = ON
If not ok: check wire to DME control unit pin 86
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Can you advise me what's wrong and how to restore it? Did he do something to my A/C relay? Has anyone used e36m42 engine in e30 and solved the a/c problem properly?

The engine stalls occasionally when idling. not sure if there is something to do with this .

Thank you.