Q – My 92 Carrera 4 blows the fuse for the climate control and then I roast in the summer heat. The circuit calls for a 25 amp fuse and that is what I have installed. Got any ideas? Pete
On a couple of these cars that we have inspected, we have found a 30 amp fuse in that 25 amp position so obviously you are not the only one. The key issue is where is the power going and why. There are two heater fan motors in the cowl area and we have measured the motor load on a number of cars. We get readings of 9.5 to 11 amps and during initial power up of the circuit, the load peaks at about 22 to 24 amps for the circuit. You can see why a 25 amp fuse is marginally adequate for the task. This does not leave much “safety factor” for that fuse.
There are other consumers on the circuit which may explain why we find 30 amp fuses in that position. In addition to the fans, the actuators and climate control head take power from that fuse too. As far as the wisdom of putting a larger fuse, this is a situation where one needs to be very cautious. For instance, if you have a 10 amp circuit and install a 20 amp fuse, you are reducing your protection significantly. This could lead to overheating and burnout on components that cost a LOT, if you can even get them anymore! Since I have no way to monitor your car, be aware of unusual odors or other symptoms related to the climate control and if it blows the 30 amp fuse, stop while you are ahead and get it diagnosed. – MC