FIXED Door Switch AND fuse question

[nd_rawlins]

Model Number

MMV4205BAB

Brand

Maytag

Age

6-10 years

My Maytag microwave (mod# MMV4205BAB) does not heat food, but retains all other functionality (light, fan, turn table, display, etc). I performed some basic tests on a lot of components with my multimeter (capacitor, diode, thermostats, transformer, and magnetron) everything looked ok. Then I found that the HV fuse was blown (my unit has 2 fuses). I am worried that a new fuse will blow if I just swap it out...especially if there is something else wrong that caused the fuse to blow.

I tested the door interlock switches and found something strange. The bottom interlock (I think it is the primary) tests normal when the wire leads are disconnected. But when I test the continuity of the wires by themselves (disconnected from the switch) there is about 75 ohms of resistance. Should this be happening? Or does it mean that I have a short somewhere in the wiring?

Thanks in advance for any help!!

 

[nd_rawlins]

Woops...I don't know how this post got put in the Whirlpool-kitchenaid forum. Sorry about that!

 

[jeff1]

Hi,

I tested the door interlock switches and found something strange. The bottom interlock (I think it is the primary) tests normal when the wire leads are disconnected. But when I test the continuity of the wires by themselves (disconnected from the switch) there is about 75 ohms of resistance.

With the wires on, you are accidentally checking something attached to those wires....have to isolate ( wires off ) to ohm test.

Then I found that the HV fuse was blown (my unit has 2 fuses).

HV fuse? You mean a thermostat? I only saw one fuse, on the filter assembly.

jeff.

 

[nd_rawlins]

Thanks for the reply. I thought that same thing about the resistance when I looked at the wiring schematic.

There are 2 fuses, both are 250V 20 amp ceramic fuses. One of them cuts power to the whole unit. The other is called the HV transformer fuse (the one that was blown) on the schematic and only cut power to the high voltage components.

Going to go ahead and just try replacing the fuse and see if it blows again...fingers crossed!

 

[nd_rawlins]

Well, it looks like the fuse fixed the problem. Hopefully it doesn't blow again soon.

Thanks!

 

[jeff1]

Glad to hear all is better

jeff.