tanreddy

Hi folks, I am a newbie here. I have a 2003 ML320. i got my Alternator replaced few years ago & ever since my A/C is not working. It is blowing ambient air. Took to a mechanic recently for A/C check. He said there is no Freon & he filled it. It still wouldn't work & he said it is Electrical problem & needed $350 to diagnose. I took it a different shop where they pulled the error codes & suggested me to take it to a dealer. Is there anything I can do instead of shelling a ton of money to the dealer?

Here are the error codes :

1) B100A - Rear Blower Motor
2) B1105 - A/C Compressor
3) B1302 CAN Communication With Lower Control Panel
4) B1303 - CAN Communication with Engine Control Module
5) B1307 - CAN Communication with Instrument Cluster

Fuses & Relays for A/C seem to work fine (Fuse 44 & the relay next to it). Do you suggest me to replace A/C compressor / troubleshoot the wiring (AAM to Relay & to the Compressor Clutch / Compressor)?
.
Appreciate any of your help / guidance.

thanks
-tanreddy

Chefcct

Tanreddy,
i suggest you investigate the control panel in the car where you adjust the temps. Mine went bad and did very similar codes to yours.
good luck

tanreddy

Thank you Chefcct! I did a little bit of driving around. Low pressure refrigerant line is not cold after the drive & is hot (eventhough the compressor is running). Is that what you had as well? When I crank up the temperature from the knob, it blows hot air & when i reduce the temperature all the way down, it blows air with outside temperature. Appreciate your help! I will investigate the control panel tomorrow.