during waiting for your reply I took it upon myself to follow the wiring diagram on the back of the unit. I traced the yellow wire back to the connector which is spliced in with another yellow wire which goes up to the thermostat inside the fridge. on the other side of the connector is one 10 gauge wire that goes to the adc board. I checked voltage on the board at the yellow wire and it reads 121v with the fan disconnected. but when i connect the fan to the harness the volage dropped to 45v. I checked voltage at all connection points and it is consistant with the readings i was getting at the fan with the harness connected. I did the same with the brown wire too....same results. btw I cleaned the connector...it has 4 plugs into it (no sign of corrosion and the connections are tight) i got the same reading on both sides of the connector.:mad:

sorry bout the double post.
ok I tried to send the unit into defrost mode and everything worked except the heater element. I did another ohm check and it was only 3 ohms. could this be the culprit (maybe an internal short inside the element) would cause the voltage drop.

Grenstreet,

First off, you basically said everything is working correctly, cools, defrosts, etc.

I'm surprised, maybe I'm over thinking this ?

Let me explain how this evaporator fan circuit works.

L1(120 vac) comes into the refrigerator and feeds line voltage to the cold control and ADC board(K terminal/red wire).

L2(neutral) comes into the ADC board (L2 terminal/ white wire).
(with everything else working, I would have to believe the ADC board is OK)

At the cold control,

The red wire, supplies 120 vac to control, as long as the cold control circuit is closed, you have 120 vac out the control to the evaporator fan motor and the K terminal on the ADC board.

At the evaporator fan ,

You have 120 vac on the Yellow wire at the fan motor,as long as the cold control is closed and calling for cooling.

Your Neutral circuit is achieved through the Brown wire at the fan motor, through the defrost thermostat(as long as the thermostat is a closed circuit), and then through to the defrost heater circuit and out the heater through the White wire going into the cabinet.

I'm pretty sure you will find your problem there.

I think the White wire is chafed inside the cabinet wall or you have a loose connection there.

Were it me, I would do one of two things:

With a meter,set to read 120 VAC,

One meter probe attached to chassis ground(bare metal or green wire).

Check each terminal for 120 VAC (yellow at the fan, brown at the fan,brown at the thermostat, etc.) the whole circuit. when or where you loose the voltage or it drops. the wire or component before the loss/drop is the bad part.

*** These are "live" voltage tests with the unit running, BE CAREFUL ***

Another test would be to disconnect the white wire at the heater, attach a wire to the terminal on the heater, attach the other end of the wire to chassis ground, or a white wire to one of the other comonents, and see if the fan runs.(if it runs, the white wire is chafed in the cabinet, and can't carry the voltage.

Let us know how it goes, and what you find,

:cool: :cool: :cool:

so....would the defrost heater being bad cause all the low voltage problems?

ordered, and thanks Joe
I will let you know as soon as i install the part

Vic