Duo-Therm A/C Clicking - Will not turn on
Hello, I have a roof mounted A/C with wall mounted thermostat. It is a Dometic Duo-Therm unit. When I flip the thermostat to A/C, I can hear it click in the A/C but nothing happens. I can get the f...
Forum Discussion
Google 'bad capacitor picture' and you might see what one will look like when 'popped'.
You can buy a $39 amp meter that clamps over one AC power wire, and will tell you the amperage going through it from Lowes Hardware.
You can also buy the $89 model that will also measure DC amperage by clamping over one wire. So it measures AC or DC amperage, just clamp it over the wire.
Both have a 'capacitance' checker, and you could remove both wires from the capacitor (with power unplugged from the RV) and test it. If it reads 35 Mfd,or whatever the capacitor is rated at, then it is good. I have replaced a LOT of bad capacitors, including one on my sister's A/C unit at her home.
With the system set to AC amps, and one wire to the compressor in the jaws, then have someone turn on the unit from below. If the capacitor was good, and the amperage is over 5 amps for a few seconds, but the compressor still does not come on, you probably have a bad compressor. You can confirm this by ohms to ground. Anything over 7,000,000 or 7.0Mohm, you will be OK. Something less, and you are likely to need a new compressor.
Considering it would take me 4 - 6 hours to install a compressor, and cost me at least $400, and that I can only warranty the replacement compressor for about 30 days labor or 90 days parts, you might as well spend $750 and get a new unit with full warranty!
Fred.
You can buy a $39 amp meter that clamps over one AC power wire, and will tell you the amperage going through it from Lowes Hardware.
You can also buy the $89 model that will also measure DC amperage by clamping over one wire. So it measures AC or DC amperage, just clamp it over the wire.
Both have a 'capacitance' checker, and you could remove both wires from the capacitor (with power unplugged from the RV) and test it. If it reads 35 Mfd,or whatever the capacitor is rated at, then it is good. I have replaced a LOT of bad capacitors, including one on my sister's A/C unit at her home.
With the system set to AC amps, and one wire to the compressor in the jaws, then have someone turn on the unit from below. If the capacitor was good, and the amperage is over 5 amps for a few seconds, but the compressor still does not come on, you probably have a bad compressor. You can confirm this by ohms to ground. Anything over 7,000,000 or 7.0Mohm, you will be OK. Something less, and you are likely to need a new compressor.
Considering it would take me 4 - 6 hours to install a compressor, and cost me at least $400, and that I can only warranty the replacement compressor for about 30 days labor or 90 days parts, you might as well spend $750 and get a new unit with full warranty!
Fred.
