Volkswagen Polo AC Not Working

[rocky89730]

Hello
Coming directly to my question, I have VW polo 2013 1.2L tdi. Recently my AC has stopped working. I visited local CAR ac mechanic. He checked wiring,condensor,fuses everything is fine. When the compressor was connected directly to power, the ac starts working. But when turned on from inside, the ac does not turn on. I press the AC ON button, the AC symbol shows in system but does not work. Need help.

 

[VISHNUCARCRAZY]

You had told he checked the wiring, what wiring had he checked?
The compressor isn't getting enough power from the car's power supply (This is easy diagnosis), but now need to see what wiring was checked?

 

[rocky89730]

He removed the insulation from the wiring near the battery. and also wires from ECU. The compressor wiring was also checked. When the compressor was connected to direct line, the AC started working and radiator fan also started spinning. The AC stopped working while driving ,what happened was that the AC stopped working when i turned the front window defrost button. After defrost i turned on AC again and it worked for 2 mins and then that was last time it worked. Now the AC doesnt work and also radiator fan works only when engine is hot as it usually woks. But when the AC is turned ON the radiator does not turn ON and i dont feel the load on the engine when AC is turned ON.

 

[rocky89730]

I forgot to add that he checked with the diagnostic tool which showed zero error.

 

[VISHNUCARCRAZY]

Its the power relay which controls the radiator as well as the kick in action of compressor (Expelling hot air out through radiator fan).

 

[rocky89730]

So i need to check relay first? And what if the relay is good and what will i be checking next? Also if the problem is with relay then why didnt it show up in the diagnostic tool? sorry too many questions

 

[VISHNUCARCRAZY]

Diagnostic tools scans sensors. sensors programmed to the OBD. In Volkswagen it is VCDS. Relay doesn't usually come in programming is what I presume. I am not 100% sure that it is the relay. But chances are leading towards relay. Normally how technicians diagnose is, they troubleshoot one by one inspecting each components associated with supplying power. It can be as simple as a fuse and as complex as finding a capacitor/ resistor on the circuit board.

 

[rocky89730]

I got it checked with 3 mechanics. 2 of them suggested me to take it to service station. Now i'm guessing the problem is with either thermostat, pressure switch or automatic climate control temperature sensor. I have to remove the dashboard for it. I guess i have to remove dashboard to even access the relays.

 

[VISHNUCARCRAZY]

It can be pressure switch, keep us posted!

 

[rocky89730]

thanks a lot. and will update soon.

 

[rocky89730]

Hello again, i replaced the pressure switch with another Polo. No,there is no problem with that also.

 

[VISHNUCARCRAZY]

I can't say about thermostat , but I still do doubt the master power supply to the Compressor>controls the radiator as well as the kick in action of compressor

 

[VISHNUCARCRAZY]

Check the magnetic clutch also that engages the compressor.

 

[rocky89730]

Sorry to keep you all waiting...i took my car to another car ac technician. He found the problem with the AC pressure switch. Hope it works.

 

[rocky89730]

Finally AC started working. The problem was with the Pressure switch. Thanks a lot