Shared Knowledge
"BMW Z3 - AC Not Cooling"
30 April 2009
Summary: it is not always something complicated.
Background:
1997 BMW Z3, 1.9 liter.
Wife's car.
AC not cooling.
Can hear compressor clutch engage when cabin AC button pushed in.
Buy a can of coolant and attach to low pressure side of AC loop.
Cheap pressure gauge indicates system is not low in coolant but not up to unsafe pressure either, so I add 1 can of coolant.
Car seems to blow cool air to me and so think done.
Next day, wife reports car still not cooling.
Check to see if fan running on AC coils mounted in front of radiator.
Fan is not running and thus heat in coolant coils not be extracted like it should be.
See fan connector on bottom of fan shroud but can not get to it through bumper grill work.
Take off plastic plate underneath bumper to gain access to fan connector.
Check fan connector for power with ignition turned on and no voltage?
Does AC fan run immediately or have some temperature switch which controls it?
Decide to see if a fuse for AC fan and find there are several related to heating and cooling.
Find one of 5 fuses related to heating and cooling is blown.
Replace fuse and start car and fan on AC coils immediately comes on.
Car interior begins to cool like it should.
Replace plastic at bottom of bumper.
Why fuse blown on front fan? Could be a lot of reasons like high water but if cooling goes again, will check fuses first and then perhaps have to replace fan.