jlsperko
07-16-2012, 10:59 PM
I am new to BMWs. I am driving my Dad's '99 323iS. I have done some research on the forums, and just need some help piecing it all together.
First off, the temp reading was always -35 degrees, so I checked to see if the ambient temp sensor was there, and it was gone. I replaced that. It now reads correctly, but didn't affect my AC.
The AC was working, then just quit. I switched on my defroster in the morning due to some foggy windows, cleared up the windows, switched back to the dash, and nothing but hot air.
Researching the forums, I saw to check the aux fan. I turn on the AC, no compressor kicking in. No aux fan. I pulled the radiator temp sensor and jumped it with a paper clip. Fan kicks on at low speed, fan kicks on at high speed. From what I have gathered, this means a new rad temp sensor?
OK... next issue. No compressor engaging. Thought maybe low refrigerant since I don't know the car. Figured I would attempt to jump the compressor to check low pressure side quick. I pulled the AC Compressor relay, jumped it, and compressor kicks right on. Aux fan also comes on at this point. Check the pressure, and it was right about 45 psi. Sounds right to me. Let it run for a minute, and it blows cold air out the dash vents. Bad relay? Is there an auto parts store to get relays (Napa, Autozone, Advance, O'Reilys)?
I tried swapping the low aux fan relay and the ac compressor relay (the ones in my fuse box appeared the same, had same black stamp but I didn't check part number). No change. Could both be shot? Wrong relay there?
Last issue... When it 'worked', I only had cold air coming out the middle setting (front of dash). If I have the upper (windshield) or lower, it just blows hot air out those, and only cold air out the middle. Does this have blend doors or something that may be stuck like other vehicles?
Thanks for any advice!
So it looks like the normal speed relay and the AC compressor relay are supposed to be different. Why mine are the same, I don't know. Does anyone have a part number for the normal speed relay?
The rad temp switch didn't make a difference. So I jumped the normal (low) speed relay, and sure enough, the fan kicked on, as well as the compressor. Looks like I will try a new normal (low) speed relay.
Does anybody have the part numbers for the low speed fan relay? My low speed fan relay and ac compressor relay are the same, and according to the wiring diagram, they aren't supposed to be.
Thanks!
First off, the temp reading was always -35 degrees, so I checked to see if the ambient temp sensor was there, and it was gone. I replaced that. It now reads correctly, but didn't affect my AC.
The AC was working, then just quit. I switched on my defroster in the morning due to some foggy windows, cleared up the windows, switched back to the dash, and nothing but hot air.
Researching the forums, I saw to check the aux fan. I turn on the AC, no compressor kicking in. No aux fan. I pulled the radiator temp sensor and jumped it with a paper clip. Fan kicks on at low speed, fan kicks on at high speed. From what I have gathered, this means a new rad temp sensor?
OK... next issue. No compressor engaging. Thought maybe low refrigerant since I don't know the car. Figured I would attempt to jump the compressor to check low pressure side quick. I pulled the AC Compressor relay, jumped it, and compressor kicks right on. Aux fan also comes on at this point. Check the pressure, and it was right about 45 psi. Sounds right to me. Let it run for a minute, and it blows cold air out the dash vents. Bad relay? Is there an auto parts store to get relays (Napa, Autozone, Advance, O'Reilys)?
I tried swapping the low aux fan relay and the ac compressor relay (the ones in my fuse box appeared the same, had same black stamp but I didn't check part number). No change. Could both be shot? Wrong relay there?
Last issue... When it 'worked', I only had cold air coming out the middle setting (front of dash). If I have the upper (windshield) or lower, it just blows hot air out those, and only cold air out the middle. Does this have blend doors or something that may be stuck like other vehicles?
Thanks for any advice!
So it looks like the normal speed relay and the AC compressor relay are supposed to be different. Why mine are the same, I don't know. Does anyone have a part number for the normal speed relay?
The rad temp switch didn't make a difference. So I jumped the normal (low) speed relay, and sure enough, the fan kicked on, as well as the compressor. Looks like I will try a new normal (low) speed relay.
Does anybody have the part numbers for the low speed fan relay? My low speed fan relay and ac compressor relay are the same, and according to the wiring diagram, they aren't supposed to be.
Thanks!