[joe shurites]

i need some advice troubleshooting. my frigerator was constantly
running and seemed as though it was not defrosting. the freezer
temp was 25 and the frig temp was 55. i removed the freezer back
panel and took a ohm reading on the heater. it read 30 ohms.
in your wiring diagram it says it should read 240k ohms. i by passed
the defrost thermostat and intiated a defrost cycle and the heater
got hot. how do you test the defrost thermostat, with freeze spray?
the timer is and heater both seem to be working.

[denman]

Here are your parts includes a wiring diagram
Replacement parts for MAYTAG MTB2456DEW REF - TOP MOUNT | AppliancePartsPros.com

seemed as though it was not defrosting. the freezer
temp was 25 and the frig temp was 55. i removed the freezer back
panel
You did not say but if the evaporator coils were not heavily frosted/iced over then you do not have a defrost problem.

and took a ohm reading on the heater. it read 30 ohms.
in your wiring diagram it says it should read 240k ohms. i by passed
the defrost thermostat and intiated a defrost cycle and the heater
got hot.
No the 240K ohms is for the defrost thermostat when it is open.
The 30 ohms for the heater is OK.

how do you test the defrost thermostat, with freeze spray?
the timer is and heater both seem to be working.
The defrost thermostat is in series with the heater and since the heater came on I would say the defrost thermostat is OK.
Forcing a defrost cycle only checks the contacts in the timer and not the motor/gearing.
Odds are that the timer is sticking somewhere during the cycle.
I would replace the defrost timer.