I have a Maytag Microwave MMV4205AAW and the blower motor runs for no apparent reason. It will sometimes turn off, but then soon turn back on. It is an over the stove model but there is no heat around the microwave when it turns on and off. It has not gotten wet to cause any short that I can tell.

I've so far replaced both thermostats but that didn't fix the problem. I can hear something click on the control panel when it kicks on, but I am guessing that click is normal. I don't want to just throw any more parts at this, so what should I check and how can I test it?

I'm currently leaving the blower motor unplugged at it's connector. Other than not having a blower over my stove, is there any problem with this?

Open the control panel. remove the control panel ribbon cable from the control board. Measure the resistance between the traces 10 & 1 for the pad "Vent Hi/Low/Off" and 10 & 5 for the pad "Vent Auto Time Set".

When pad touched, it should read less than 400 Ohms. When pad is not touched, it should read more than 1 mega ohm.

If any of the readings is incorrect, replace the control panel.

- The control panel Part number: AP4057134