Hi,

 

I got 1.9TDi (ALH) 2003 Octavia, 350k kilometers in odo. Air conditioning has been working fine and blowing ice cold immediately when I press the button. Today, I was driving with AC on and noticed very strong burning smell coming from vents when I stopped at traffic lights. Pulled over, hood up, same smell from engine compartment but I had zero visible damage. Aux belt was fine, no noises. I drove home and noticed that the AC was not blowing cold air anymore. When I press the button I see a small dip in the tachometer and one of two auxiliary fans goes on but no cold air. The burning smell incident and dead AC must be related. Tomorrow I wlll begin troubleshooting but could somebody give me some hints to guide me? Is there any known weak spots in Octavia ac-system?

Edited 18 April, 20197 yr by skodist6

Sounds like one of your radiator fans has died, maybe causing the burning smell as it did?

1 minute ago, Wino said:

Sounds like one of your radiator fans has died, maybe causing the burning smell as it did?

So both of the fans should activate when I engage AC? But my AC doesn't blow cold even if I drive highway with AC on. Shouldn't the air flow cool down the AC-cell while driving (even without second fan)?

Yeah, I think the fans are wired in parallel. Which one isn't running?

1 minute ago, Wino said:

Yeah, I think the fans are wired in parallel. Which one isn't running?

Left one. (A fan that is closer to the battery.)

1 hour ago, Wino said:

Yeah, I think the fans are wired in parallel. Which one isn't running?

 They are in parallel

If the air con is not working at all I would think its the compressor clutch coil that has burnt out. I wouldn't think one dead fan would stop the air con from working unless its blown some fuses

I did some troubleshooting tonight. Fuse #16 is fine. In cold start with AC on, both auxiliary fans start immediately. The compressor shaft feels fine when spinning by hand. Compressor clutch doesn't engage, it sounds logical that burning smell came from compressor clutch like SuperbTWM said. The compressor is made by Sanden, model: SD7V16. Already looked at Ebay and only the clutch is sold separately. Has anyone changed that? It looked like simple job in situ. Belly pan off, nut off, clutch off and reverse with new part.

Edited 20 April, 20197 yr by skodist6

4 hours ago, skodist6 said:

I did some troubleshooting tonight. Fuse #16 is fine. In cold start with AC on, both auxiliary fans start immediately. The compressor shaft feels fine when spinning by hand. Compressor clutch doesn't engage, it sounds logical that burning smell came from compressor clutch like SuperbTWM said. The compressor is made by Sanden, model: SD7V16. Already looked at Ebay and only the clutch is sold separately. Has anyone changed that? It looked like simple job in situ. Belly pan off, nut off, clutch off and reverse with new part.

 

Yes its a piece of cake, from memory there may be a circlip as well

Here's the info from the manual Octy AC Clutch Replacement.pdf