Walk-in freezer Fans wtf.

[Snapperhead]

Skipping defrost coupled with strange fan behavior sounds more like a defrost terminator/fan delay switch problem to me. The epoxy seal on those breaks down over time and they fill with water.

Yea I've witnessed very odd voltages when water gets in switches. You will get like 98 volts or 66 or somewhere inbetween , and the fan runs slow

and like said above .... the case might just shock the hell outta you

[mmmdave]

Yup, any time I see an iced evaporator, first thing I do is mark the clock. Then continue with preliminary inspection and gathering model/serial info.

I've definitely seen dtfd's cause the defrost timer issue as previously described. It terminates the instant it starts, so to speak.

But, for what it's worth, I've seen fan behavior just like this which was caused by residual ice in the core of the evaporator, which blocked air flow through the coil and so the only other place for the air to travel through was through the "weaker" fan, fighting against it. (Note that weaker doesn't necessarily mean a defective fan, but in this scenario, one of them will dominate the other.) Pull the blade assembly off of the slower fan and see if the motor comes up to speed. And get a -bright- lite and make sure that coil is clear all the way through.