[idahjo]

With the evaporator panel removed, the first 1/3 ONLY is frosty. Density of frost around the inlet tubing and around the bimetal sensor is very heavy... tapering down to nothing at about the 1/3 point.

Does this indicate specifically low freon or could it be a failing/inefficient compressor?

Thanks kindly, and it appears the problem has been traced out to a TERMINAL condition for all practical purposes?

[woodchuck]

Unless the bottom heater is keeping the lower 2/3 clear and your top heater isn't working. Although that much frost should be melted by the defrost system, it could be compressor or freon.

[idahjo]

Thanks Woodchuck. Appreciate all of the information, this was a learning experience! The 'Old Girl' is enroute to the dump.