[Papa Bear]

Some information to start. I have a 2002 330CI. I began having some cooling issues so I decided to beef up the system a little bit. An aluminum radiator and flexalite controller later, I begin to have AC issues. The blower will run but no cold air will begin flowing. The FSR is new, fuses and relays are confirmed working, and the compressor clutch was confirmed to be working. My question is: if the stock fan is removed and nothing plugged in, will the IHKA fail to send a signal out to the compressor?

 

[armenh7]

Some information to start. I have a 2002 330CI. I began having some cooling issues so I decided to beef up the system a little bit. An aluminum radiator and flexalite controller later, I begin to have AC issues. The blower will run but no cold air will begin flowing. The FSR is new, fuses and relays are confirmed working, and the compressor clutch was confirmed to be working. My question is: if the stock fan is removed and nothing plugged in, will the IHKA fail to send a signal out to the compressor?

I believe not. The fan must be seen as functioning in order for the compressor to kick in

 

[Papa Bear]

You wouldn't happen to know how one would go about tricking the computer into thinking it's functional would you?

 

[markusmarkus]

You wouldn't happen to know how one would go about tricking the computer into thinking it's functional would you?

In stall a factory fan.

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[randy72877]

You need to use a pwm fan control that allows the dme to control the fan. Get rid of the flexalite control that probably just has a temp probe in the radiator. Bmws fan control is far superior to any little aftermarket box. If your original fan has the separate control (early version had it integrated with the motor) you can use that to control your aftermarket electric fan. Unfortunately if the original fan fails it's usually the speed controller that fails but it seems that you are trying to upgrade cooling so maybe your original fan works? Is it manual or auto transmission? There are other makes and models that have compatible fan controllers that can be found used (junkyard or ebay) but I don't remember the exact vehicles. There are threads about replacing the fan controller (not available separately) or you can install a puller fan from a manual transmission car if you have a belt driven fan and want to eliminate it.

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[Papa Bear]

You need to use a pwm fan control that allows the dme to control the fan. Get rid of the flexalite control that probably just has a temp probe in the radiator. Bmws fan control is far superior to any little aftermarket box. If your original fan has the separate control (early version had it integrated with the motor) you can use that to control your aftermarket electric fan. Unfortunately if the original fan fails it's usually the speed controller that fails but it seems that you are trying to upgrade cooling so maybe your original fan works? Is it manual or auto transmission? There are other makes and models that have compatible fan controllers that can be found used (junkyard or ebay) but I don't remember the exact vehicles. There are threads about replacing the fan controller (not available separately) or you can install a puller fan from a manual transmission car if you have a belt driven fan and want to eliminate it.

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My car is a manual and I don't have the stock fan. There's gotta be a way to wire it up so that the AC works. Does anyone have a wiring diagram for the HVAC system? spaghetticoder isn't a valid site anymore.

 

[BaliDawg]

My car is a manual and I don't have the stock fan. There's gotta be a way to wire it up so that the AC works. Does anyone have a wiring diagram for the HVAC system? spaghetticoder isn't a valid site anymore.

You really should install a proper OE fan unit back in there. Trying to trick the DME is going to be a pain.

But, in case you don’t, here are some useful links for ya.

BMW-North’s electric fan guide
https://drive.google.com/file/d/1CacccXaYp4SDvAJgIFOlAvgBTPQDJx6u/view

Troubleshooting electric fan
https://forum.e46fanatics.com/showpost.php?p=14652919&postcount=19

E46 climate control tech docs
http://v12.dyndns.org/BMW/BMW 3 (E46)/8 Climate Control.pdf

HVAC wiring diagram for your car
https://www.newtis.info/tisv2/a/en/e46-330ci-cou/wiring-functional-info/body/

 

[randy72877]

The easiest way is to use an original type puller fan, but you can also use one of the fan controllers from the bmw north fan guide to run your aftermarket fan. The dme needs to be able to control the fan. If the dme doesn't detect a functional fan connected you won't get a/c.

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[mcycleserv]

you seem to be switched on with A/C problems

You need to use a pwm fan control that allows the dme to control the fan. Get rid of the flexalite control that probably just has a temp probe in the radiator. Bmws fan control is far superior to any little aftermarket box. If your original fan has the separate control (early version had it integrated with the motor) you can use that to control your aftermarket electric fan. Unfortunately if the original fan fails it's usually the speed controller that fails but it seems that you are trying to upgrade cooling so maybe your original fan works? Is it manual or auto transmission? There are other makes and models that have compatible fan controllers that can be found used (junkyard or ebay) but I don't remember the exact vehicles. There are threads about replacing the fan controller (not available separately) or you can install a puller fan from a manual transmission car if you have a belt driven fan and want to eliminate it.

Sent from my SAMSUNG-SM-G870A using Tapatalk

Hi Randy maybe you may be able to help..I have 2002 323i Msport and yes that is correct 323i Auto "with tiptronic gear change" ..cause they were still being delivered to Thailand ...I checked the A/C with manifold gauges and the system read 32LP and 140HP,.lost a bit of gas when I disconnected gauges mostly from HP port
Problem is A/C Aux fan ...A/C cut out and I took it to a so called mechanic who added a bit of gas ..he only hooked up LP side and gauge read about 20+psi so he charged it to 31psi ..system worked for a few hours but just started blowing hot air .I noticed when he hooked up the yellow port he did not purge any of the lines .
the compressor still works when turned on but the Aux fan only switched on for maybe 1 minute and cuts out ...leave the motor sit for about 1 hour and compressor turns on and so does Aux fan but cuts out again
My theory is not enough gas in system and the HP must be low ....question ....on the Dryer would the HP switch control Aux fan so if pressure is low would cut out fan ...Wifie said the A/C worked when traveling at speed on expressway
I have gauges but R134a is on the way along with ultra violet kit and Vacuum pump just incase I have to strip the system .
waiting for your expertise on this

 

[randy72877]

Hi Randy maybe you may be able to help..I have 2002 323i Msport and yes that is correct 323i Auto "with tiptronic gear change" ..cause they were still being delivered to Thailand ...I checked the A/C with manifold gauges and the system read 32LP and 140HP,.lost a bit of gas when I disconnected gauges mostly from HP port

Problem is A/C Aux fan ...A/C cut out and I took it to a so called mechanic who added a bit of gas ..he only hooked up LP side and gauge read about 20+psi so he charged it to 31psi ..system worked for a few hours but just started blowing hot air .I noticed when he hooked up the yellow port he did not purge any of the lines .

the compressor still works when turned on but the Aux fan only switched on for maybe 1 minute and cuts out ...leave the motor sit for about 1 hour and compressor turns on and so does Aux fan but cuts out again

My theory is not enough gas in system and the HP must be low ....question ....on the Dryer would the HP switch control Aux fan so if pressure is low would cut out fan ...Wifie said the A/C worked when traveling at speed on expressway

I have gauges but R134a is on the way along with ultra violet kit and Vacuum pump just incase I have to strip the system .

waiting for your expertise on this

You said the ac works when driving on the expressway but cuts out when not moving. This sounds like a cooling fan problem. To test the fan you can disconnect the radiator outlet temp sensor (electrical connection only) in the lower radiator hose. This will cause the dme to run the fan at full speed constantly. Do this simple test first to check if the cooling fan is ok.

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[mcycleserv]

reply to Randy

thanks for the info ..did try that disconnect on temp S/U but still the same ...fan works on and off ..like last night it was working ..started car this morning and fan worked then cut out after a few seconds ..unplugged S/U then checked voltage to fan connector (+-)and has 13.65v.am wondering still dryer pressure switch if it goes back to DME through the 3rd wire from fan connector block .is maybe signal wire to resistor box on fan assy Aux fan is not that old ..replaced it maybe 10000mls with OEM and still looks relatively new ...I did see on youtube some guy had the same problem and replaced fan and it was a no fix ..turns out he said was air in system...is strange that when the system has R134a added everything worked ..but not for long ...

 

[BMW-North]

The fan speed signal sent by DME is impacted by the the AC refrigerant pressures. IHKA calculates and sends to DME these values and if they are outside acceptable thresholds DME commands AC off. That would turn your e-fan off if another input didn't satisfy the calculation to command the e-fan ON.

You need to perform an INPA test to ensure fan responds correctly to DME requests, then ensure the AC pressures are correct and within specified tolerances.

You should also verify the engine temps are not abnormally high. DME will also turn off AC if it thinks the engine might overheat. It does that in 4 minute cycles but the e-fan should be blowing hard if that was the scenario, unless the fan interpreter was bad and DME thinks the fan is running. That might explain why AC works at speed as the temp stays below the threshold. Again an INPA fan test will reveal.

 

[mcycleserv]

thanks for the reply

ok what you are saying makes sense ..have INPA but have not had anything to do with AC on INPA ..is there a tutorial on checking AUX on INPA and can you give me what the STD LP and HP lbs should be with outside temp around 80f have A/C manifold guages just need a tyre lever to get wifie out of the seat so I can check it :banghead::banghead::banghead:

 

[BMW-North]

ok what you are saying makes sense ..have INPA but have not had anything to do with AC on INPA ..is there a tutorial on checking AUX on INPA and can you give me what the STD LP and HP lbs should be with outside temp around 80f have A/C manifold guages just need a tyre lever to get wifie out of the seat so I can check it :banghead::banghead::banghead:

There's a section in this guide (link below) about checking the fan using INPA. There's also a link to a youtube video somewhere within it. The INPA test assumes you are using a stock setup (original or aftermarket fan controller). There's also some tech data on the AC and the e-Fan dependencies.

Fan Guide

 

[mcycleserv]

Inpa

thanks for this information
hooked up manifold gauges and started motor and same problem ..hooked up OBD and INPA and did a fan check and fan is working with tests 25%.50% and 75% allgood
when fan started working so did the A/C added gas and checked gas pressure on gauges 35LP and 150+HPpsi run car for a few minutes to OP temp and Aux fan revs varied when LP and HP increased LP is 43 and HP is 218psi do these values seem ok ...when I did my training in mech engineering air con was when you opened the windows :hi:
thanks for this info..I think the A/C control unit may have been the problem so I know the later upgraded version 2003-2006 unit is better so I might see if I can source one on Ebay

 

[BMW-North]

I***8217;m not an Ac expert. There are better qualified folk on here. As far as I know the LP side should read 30-40psi and the HP 150-250 psi so those numbers look ok. Is the AC pressure sensor and connection in good shape?

 

[mcycleserv]

just had a call from Wifie and A/C is still working ok...see what happens when she returns and is stuck in the traffic for a few hours