[turbothedave]

I'm trying to fix the refrigerator of a lady down our road. It had the classic frost on the back of the freezer section, and a refrigerator that was not as cool as should be, suggesting a defrost issue. I pulled the panel, and there was ice EVERYWHERE! So definately a heater issue.

Got the meter in hand, pulled the terminals on the heater, and it checked out as open circuit - so that was definately faulty, but I wanted to check the Timer was working as well before ordering any parts, so connected my meter across the heater contacts (heater was out at this point) and I was surprised to see that there was around 30V at the terminals.
When I manually cycled the timer, it went up to 120v when in defrost mode, but as soon as it switched back to 'normal' mode, it was back to 30-ish volts.

So, is this right? I can't possibly imagine that it is right - it's suggesting a partial short, or is there a capacitor somewhere, or perhaps a resistor to keep the heater on 'low' all the time? I don't have a wiring diagram so don't know if there is anything to make this voltage...

Thinking about it now, I should have unplugged the timer to see if there was still voltage at the terminals - perhaps I'll do that tomorrow....

I'm probably just going to get the full defrost / thermostat assembly (AP2071521) - at $6 more than the heater alone it seems silly not to replace it. I'd just like some input to the voltage thing first.

Thanks!

[turbothedave]

Defrost heater voltage

I found the above (similar) question asked previously, but no answer or suggestion was given...

[denman]

No there is nothing in the unit that should keep the heater on low all the time.

There should be 0 volts at the heater when not in defrost.

That said what you see is probably ghost voltage.
You will not know till you replace the heater.
I would bet that the heater will not have any heat when it is supposed to be off.

I do not know how much knowledge you have about electricity so will try to explain.
The unit runs on AC so the wires give off a 60 hertz alternating electromagnetic field. Depending on how wires are orientated to each other this can induce a voltage in another wire. This is how a transformer works but they have many many windings. Although you see voltage there, there is no significant amount of power, to push electrons and provide a current (amps).

So you see the voltage but it has no substance (power) re: it is ghost voltage.

[turbothedave]

Thanks - I was pretty sure that there was something not right about that. Perhaps because the wires are encased in the ice and wrapped around the condenser is doing strange things...

I appreciate the feedback.

[turbothedave]

Well you were right. With all the ice gone, there was only 7 volts today. I unraveled the big lump of wires on the top left of the freezer section, and it dropped to three volts. Touched the wires together, dropped to zero, then back to three.
Strange stuff this AC ha ha ha.

Going to order the WR51X10029 right now (Sunday Night). Let's see how fast these AppliancePartsPros guys can get a part to my doorstep!