What to do when the blower motor quits working.
The Problem: When the air conditioner is switched on, you can hear the hum of the compressor, but the fan doesn't blow.
Solution 1: If the blower doesn't spin freely by hand with the power off, the motor bearing may be dried out. A couple of drops of oil and manually turning the motor for a minute may be the solution. Put the oil on the shaft right where it comes out of the motor. This recently happened to mine. It now works better than it ever has. I will likely have to do this again someday. Next time I'll have a better oil for this job. If your motor already spins freely, but just won't start, then move onto the next item.
Solution 2: Replace the bad capacitor for about $6.00.
If you have an RV, chances are you have a Coleman Air Conditioner. One of the most popular brands on the market. The do work very well, but they do have a weak spot... the start capacitors. I have seen them fail after 3-5 years of use. I've repaired a number of them. It's simple and inexpensive.
All the work will be on the outside portion of the air conditioner. Make sure you disconnect all sources of electricity before starting work! On the models I've worked on, there are 4 screws on the top of the plastic shroud. They have a little Loctite on them and are rather tight to remove. The cover must be lifted straight up or it will bind.
Once the plastic shroud has been removed, you'll end up with something like the picture above. On the left front corner is an access panel with a few screws. Remove the screws.
Inside the access panel, you'll find the capacitors. There's a diagram on the back of the access panel door. Look for the blower motor capacitor in the diagram. The diagram will show what color wires connect to this capacitor. It's also likely that the capacitor can will be distorted and some fluid may have oozed out. Remove this capacitor by unscrewing the clamp holding it in place, then pull the wires free. These wires are not polarity sensitive, so you can't reconnect them backwards. WARNING: Capacitors are designed to retain a charge. If the capacitor is still good, chances are it still has a charge. Take a screwdriver and short across the contacts while holding only the plastic screwdriver handle (to insulate you). Better that it arc across your screwdriver than your fingers.
Note: If you find more than 1 capacitor bad, take note of which wires go to which capacitor. Tape and a Sharpe marker can make this job easier. You could also rely on the diagram.
The replacement capacitor might be a different physical size. That doesn't matter. As long as the electrical specifications are the same, it'll be fine. The clamp used to hold the capacitors are adjustable, so if the replacement is a little larger or smaller, the clamp will easily accommodate.
Put it back together in reverse order. Should be happy for several more years.
Emergency Tip: If you find that your A/C has quit working while on a camping trip, there is a simple fix. Turn off your A/C, remove the INSIDE shroud. Reach up inside and feel for the squirrel cage blower. Give it a spin with your finger tips, then get your hand out of the way, and turn on the air conditioner. Since the blower is already spinning, the motor can start without a start capacitor. Just don't turn off the A/C the remainder of that camping trip, or you'll need to spin it again. Be very careful not to have your hand inside the unit when applying the power. This hand starting technique saved a camping trip. It was hot, the camper was already setup, and the blower wouldn't run. Since I had prior experience, I knew what the problem was and how to get the A/C running once again.
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Last updated 03/14/05 All rights reserved.