Maxima 2000 SE.

all of a sudden, my blower motor fuse burnt out. They are 2 15Amp fuses, all burnt. OK? I put new ones on, get burnt in 1 day. test done as below:

turned blower motor on, no problem.

turned on AC, no problem

manully upspeed blower motor, no problem

maunlly downspeed blower motor :---- flash! and fuses are gone....


I took the resistor out, it feels warm, some corrosion found on surface.

My question: is the fuse burnt out because of resistor expired?

Thanks in advance

 

I don't think the resistor could be doing this. The way the fan motor works is that one side of the fan motor is connected to the fuses. To make the fan spin, the other side of the fan motor is connected to ground. For high speed, the fan is connected directly to ground. For slower speeds, the resistor gets connected between the fan motor and ground.

Translation - you have a bad fan motor.

 

I've just done blower motor service, WD-40 to axis bearings. no extra resistance felt when I spin it today.

 

All that means is that the bushings are good. The brushes that ride on the communtator are probably worn out.

 

Checked the FSM yet?

 

sounds good! checked. don't find close issues. temp control well, motor runs good, fuse..... burnt......

 

It happens when you turn it down? Might as well replace the resistor

 

problem solved. After disassembled motor and the resistor, I found some small rust and burnt spot around 3 welds. They're actually getting too close because of corrosion between them. short circuit must be happenning somewhere sometime. I cleaned around all welds. Now no fuse problem.

Thanks fellows.

 

came in to post this


when rust gets built up on the resistor contacts, it literally " adds " metal which in turn lowers resistance and when you lower resistance, you increase amperage , and when amperage gets increased and it exceeds the current rating on the fuse that protects the circuit....***POP!*** It blows the fuse


Just some FYI