03 e53 AC problems

[jimdanforth]

Originally Posted by 80stech

As already suggested, aux fan not working could be another issue.

I could believe that but I can activate the fan with INPA

[80stech]

I'm not familiar with the non IHKA (auto temp) set up, but it sounds like it's not seeing or liking something. If you can work all the outputs through IMPA but still have no air there must be an input missing.

You could try pulling the lower rad hose temp sensor and see if the DME turns on the aux fan just to see if it has some control of it.

You could also try defrost to see if that kicks the compressor in.

[jimdanforth]

Originally Posted by 80stech

I'm not familiar with the non IHKA (auto temp) set up, but it sounds like it's not seeing or liking something. If you can work all the outputs through IMPA but still have no air there must be an input missing.

You could try pulling the lower rad hose temp sensor and see if the DME turns on the aux fan just to see if it has some control of it.

You could also try defrost to see if that kicks the compressor in.

I'll try the temp sensor. Did already try defrost. Too hot today to even try

[jimdanforth]

Auxiliary fan does not engage with lower hose temp sensor unplugged, but does when activated in INPA and is speed controllable there.

[80stech]

Well that is interesting. I'm thinking the aux fan maybe doesn't pass the test for the DME but doesn't need to if it gets activated through INPA. Can you read the evap temp in INPA?

[jimdanforth]

Originally Posted by 80stech

Well that is interesting. I'm thinking the aux fan maybe doesn't pass the test for the DME but doesn't need to if it gets activated through INPA. Can you read the evap temp in INPA?

Don't remember seeing that in INPA, but I cant get into the AC module at all. I kinda assumed it was since I have manual controls

[80stech]

Hopefully someone who knows something about the manual controls will chime in. You should probably get a wiring diagram and theory of operation for the manual controls. It still could be the aux fan but that will be hard to eliminate without having a known good one to plug in.

I see in your first post INPA is showing the A/C input and compressor, that is from the DME then ? Is there even an A/C module ? I know the Evap temp sensor is different for the manual controls so maybe there is not even an A/C module ??

[jimdanforth]

Originally Posted by 80stech

Hopefully someone who knows something about the manual controls will chime in. You should probably get a wiring diagram and theory of operation for the manual controls. It still could be the aux fan but that will be hard to eliminate without having a known good one to plug in.

I see in your first post INPA is showing the A/C input and compressor, that is from the DME then ? Is there even an A/C module ? I know the Evap temp sensor is different for the manual controls so maybe there is not even an A/C module ??

I think I'll chase the aux fan issue. It's apparently not right anyway and it may be the key to half of this problem. I'll start a fresh thread with details.

[80stech]

When you say there is no voltage at the compressor clutch, have you measured or are you assuming there is no voltage because the clutch doesn't cut in ? Have you tried revving the engine to get the compressor compressing ?

[jimdanforth]

Originally Posted by 80stech

When you say there is no voltage at the compressor clutch, have you measured or are you assuming there is no voltage because the clutch doesn't cut in ? Have you tried revving the engine to get the compressor compressing ?

I measured it. Pierced the wire and took voltage. It does come up when the INPA turns it on, but not when I request it from the temp selector.
Yes, I did rev the engine to near redline with INPA turning on the compressor, and still no delta on the gauges. Tried without INPA just to cover all options and it still not not engage or change pressure.