GuruX
A2OC Donor
A lot of threads are here about a hunting or breathing cabin fan. This is caused by the J126 controller going bad. As usual with electrics, it's just a matter of solder joints gone bad. This can be confirmed by removing the glove box, set your fan to a speed that doesn't work properly and then press the connector block to the controller with your finger. The fan rpm should vary with the pressure of your finger.
To find the J126 fan speed controller (in Swedish it's usually known as a heater fan resistor), follow the cable from your cabin fan, away from the fan. The first thing it connects to is the fan controller.
This part is removed by first removing the cabin fan, then the controller which is held on by a single screw. The controller isn't meant to be repaired, the circuit board is covered with a black rubbery paste. The paste can't be removed easily. But hey, someone put this together, I must be able to take it apart.
What you'll need are small torx bits. I think they might be TH6 and TH10. I managed however with a single TH8, and some luck. What you really need to know, is the location of the screws holding the circuit board. I couldn't find all of them, and broke my unit, but I'm sure I could have repaired it if I didn't break it during disassembly.
As you can see. There are seven screws. Two of them, holding the connector block, can be seen without removing the black stuff. Three of them in the edges hold the transistors, and two of them hold the circuit bord.
I would find them all, remove them and then use an exacto knife to cut along the edges of the unit. There is a gap between the housing the circuit board on the long sides. This gap is about 1,5 mm, so be careful. You should get the circuit board and the connector block out in one piece. On the underside of the circuit board, you'll probably find cracked solder joints, resolder and then reassemble in reverse. Perhaps you should also restore some of that black muck, to protect the circuit board from condensation.
Good luck!
To find the J126 fan speed controller (in Swedish it's usually known as a heater fan resistor), follow the cable from your cabin fan, away from the fan. The first thing it connects to is the fan controller.
This part is removed by first removing the cabin fan, then the controller which is held on by a single screw. The controller isn't meant to be repaired, the circuit board is covered with a black rubbery paste. The paste can't be removed easily. But hey, someone put this together, I must be able to take it apart.
What you'll need are small torx bits. I think they might be TH6 and TH10. I managed however with a single TH8, and some luck. What you really need to know, is the location of the screws holding the circuit board. I couldn't find all of them, and broke my unit, but I'm sure I could have repaired it if I didn't break it during disassembly.
As you can see. There are seven screws. Two of them, holding the connector block, can be seen without removing the black stuff. Three of them in the edges hold the transistors, and two of them hold the circuit bord.
I would find them all, remove them and then use an exacto knife to cut along the edges of the unit. There is a gap between the housing the circuit board on the long sides. This gap is about 1,5 mm, so be careful. You should get the circuit board and the connector block out in one piece. On the underside of the circuit board, you'll probably find cracked solder joints, resolder and then reassemble in reverse. Perhaps you should also restore some of that black muck, to protect the circuit board from condensation.
Good luck!