Chrysler Repair: 2000 Cirrus Heater Problem, amp fuses, fuse box

Question
The heater register has blown 2x first time replaced it blew after 3 months. the second replacemnt blew after 2 weeks. what could be wrong. is it the register, or something else?

Answer
Hi Amyn,
I assume by "register" that you are referring to the resistor block. About the only thing that would cause the resistor block to blow out so easily is the fan motor is drawing too much current which overloads the resistors or there is a short circuit in the wiring in that circuit so that too much current is drawn. To protect against the resistor block blowing again you might want to reduce the size of the fuse #1 (in the fuse box under the dash) from 30 Amp to 25 Amp so that the fuse might blow rather than the resistor block. Perhaps you can determine whether it is blowing on a particuar speed setting and then avoid using that setting of the fan speed. Other than that a new fan motor might solve the problem. So start with buying a box of 25 amp fuses and a new resistor block and see if you can 'cushion' the block against being blown while you figure out what operating speed seems to cause the circuit to overload. If you are inclined to doing circuit analysis I can send you the wiring diagram and you could check for a short circuit. But I suspect the fan motor might be causing the resistor block to be overloaded and to blow.
Roland