Originally Posted by RudysDad
I have a Dometic A/C that the fan doesnít seem to want to work on. When turned on I get the hour glass timer to show. I hear the compressor start up but no fan. Then after about 30 seconds it starts the process over. It wonít work just on the fan setting either. Is there a separate fuse somewhere for the fan or is it possibly seized up? Zones 2&3 work fine. Only problem is zone 1. What should I be looking for? Thanks for any help you can give me.
It would be helpful to have the model number of the unit. Test procedures and diagnosis vary greatly between models.
Be fore you start throwing parts at it you need to do more testing. In this situation you will need a helper.
Yes, first test the capacitor. Hopefully it should have the rating printed on the outside along with a part number.
Since you say you know the compressor starts but the fan does not. Unplug the line in side of the capacitor and check for AC voltage in. If you have ac voltage in pug it back in and check for AC voltage out. You can also run the fan bypassing the capacitor. Not a recommended procedure but I have bypassed them for a few to 15 seconds just to see if the fan will turn. Just make sure you have every bit of power draw off, all ac's off, and turn on only the fan, not the AC. If you have to trip the breakers off for the working ac's so they don't try and start their fans.
If it still doesn't start, I have made a small jumper cord that plugs into the two lines in to the fan. Your just plugging an extension cord with two terminals into the fan. PLUG THE TERMINALS INTO THE FAN BEFORE PLUGGING THE EXTENSION CORD INTO 120 volts If the fan starts you know your fan is good.
The next test is the line out from the circuit board to the fan capacitor. If you get 120 there when you turn the fan on, you can be pretty much assured that your capacitor has gone bad.
If not, it could be the circuit board. Testing them is beyond me. If I think that's the problem I take the board to somebody to have it tested.
AND REMEMBER, WHEN WORKING ON CAPACITORS THEY STORE VOLTAGE. Drain off the voltage with a VOM or even a screwdriver from the body to the terminals. Do each terminal. If you have ever been zapped by a capacitor you will know why.