Air Conditioning Problems Possibly Electrical

[Daffyduck]

Hi all

Your advice would be very much appreciated.

Air con not working on a Mazda 5 recently purchased. Gas refilled and schrader valve replaced. Pressure checked and no leaks. Turned on A/C and compressor not engaging.

Plugged into computer to check that there were no problems and one appeared on list. ODB code B1260 Solar Radiation Sensor short to ground. Replaced this sensor (on top of dash) but the error code is back and no compressor engagement.

Is there a straight forward answer to this or is it going to be an electrical gremlin nightmare?!

Thanks in anticipation.

Jason

 

[loosenut]

Disregard the b1260. That will set during self test if not enough light is shining on the sensor. You need to check for voltage to the a/c compressor clutch with the engine running and a/c turned on manual high. If battery voltage is present then either the compressor clutch has failed or the compressor is damaged. Attempt to turn the compressor by hand with the engine off (grab the very end on the outside of belt). It should turn with some resistance. If it doesn't turn then the compressor is locked up. The compressors on the 5's and 3's have a high rate of internal failure.

 

[chad99]

Do what loosenut said (as mentioned manual MAX cold setting) then if batt voltage is NOT present at compressor when it should be, it could be (In order of easiest thing first):
A/C relay fuse
A/C relay itself
You put in too much R134..I don't see a DTC listed for over press but if the high side is above 3.14MPa or 455psi it says it will keep a/c off.

 

[Daffyduck]

Hey guys

Thanks for your replies, very helpful. I think the air con has not been looked at for a while by previous owner. Could the high/low pressure switch be something to check as well as power to the compressor?

I forgot to mention in my first post that the fan comes on when you set the A/C to manual and max asthough it is trying to run the system!?

Regards

Jason

 

[00bluees]

i have a similar issue. last year my a/c died on me and i replaced the compressor with a scrapyard unit. open removal of the old compressor it seemed to be an electrical issue (the clutch not engaging) and the compressor impeller wasn't damaged, the system pressure and charge were correct and there was enough oil in the compressor. after a year, the same thing has happened, everything checks out except the clutch is not engaging. fuses are fine, relays are fine, fan comes on but not the compressor. i don't want to replace the whole unit again, and clutch assemblies seem hard to come by. anything that could be done to rectify the issue without replacing parts? or should i try a new clutch assembly.

 

[Daffyduck]

This turned out to be a faulty compressor. Compressor changed and all good now.