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I have a 12 year old 14 SEER Amana RCE36C2C condensor mated to a Amana AMS95 17" wide air handler. It has been a good setup, after correcting some installation flaws I won't get into here.
Recently I noticed the condensor fan was running full time, although not at full speed. I cycled the AC at the thermostat, and the fan correctly shut off at the end of the cycle. I should note I saw a flash of light when the relay engaged under command from the 24V thermostat. A couple days later I went out there (it is heating season now, AC hasn't been turned on) and the fan was running slowly again. So I pulled the fuse disconnect in the wall-mounted junction box to shut it off.
I looked at the schematic and it seems pretty straightforward. As far as I can tell there is no path to power either the fan or compressor except through that relay. I'm thinking the relay is bad, but this seems a strange behavior - the fan being powered at a low setting. Maybe 1 leg of 220V? As an aside, the start-run capacitor was replaced a few months ago, although I don't think the fan running slowly issue started at the same time. After doing some reading online I realize it may be only one leg of the 220V is switched, so a winding short to ground could allow some power through the motor. I'll ohm out the motor to check this weekend. I think the bearings are getting worn anyway as I hear some rattling. I would like to make sure to replace the correct part, however, the bearings aren't bad enough to justify replacement by themselves I don't think.
Has anybody seen this symptom before?
Recently I noticed the condensor fan was running full time, although not at full speed. I cycled the AC at the thermostat, and the fan correctly shut off at the end of the cycle. I should note I saw a flash of light when the relay engaged under command from the 24V thermostat. A couple days later I went out there (it is heating season now, AC hasn't been turned on) and the fan was running slowly again. So I pulled the fuse disconnect in the wall-mounted junction box to shut it off.
I looked at the schematic and it seems pretty straightforward. As far as I can tell there is no path to power either the fan or compressor except through that relay. I'm thinking the relay is bad, but this seems a strange behavior - the fan being powered at a low setting. Maybe 1 leg of 220V? As an aside, the start-run capacitor was replaced a few months ago, although I don't think the fan running slowly issue started at the same time. After doing some reading online I realize it may be only one leg of the 220V is switched, so a winding short to ground could allow some power through the motor. I'll ohm out the motor to check this weekend. I think the bearings are getting worn anyway as I hear some rattling. I would like to make sure to replace the correct part, however, the bearings aren't bad enough to justify replacement by themselves I don't think.
Has anybody seen this symptom before?