AC problem

dpgerson wrote:
When I turn it on the engine hums but the fan doesn’t blow and no cold air comes out.

Truck A/C or the camper A/C?

Try running the fan without the air conditioner. If you get the same symptom (fan not running) sometimes spinning the fan by hand with a stick may get it going until you stop it. Remove the shroud on top of the air conditioner and usually a sheet metal panel. Unplug from shore power before you proceed.

There are usually two capacitors. The big one has connections for fan, herm, and ground. Clean connections and try again. Should be slip spade connections. Take a picture or write down a diagram for which wire goes where. Test capacitors with a meter. They are labeled on the side for micro farads. Good multimeter needed that has this feature. Some are riveted spade connections on top of the capacitor and these can become loose also like mine was! Soldering the spade male connector on top of the capacitor to the rivet may fix if found loose and the cap tests good. Otherwise replace capacitors with new one at a time and retest.

I bought a spare 15 years ago and have not had to use it yet but I got it!

It may use a capacitor in the start circuit, these can and do go bad and will cause this. I is a very easy fix to replace one, you really do not have to worry too much about getting the exact value either just close. a quick Google search should pull up plenty of what I am talking about here.

Sometimes you can just look at it and see that is out of shape, busted or leaking.

Phil

Hi,

Get access to the fan. Apply power. Spin the fan. That, so far, I've had to do once per year (after winter storage).

Sounds like the motor is froze up. Try taking cover off and if you can oil the bearings of fan. WD40 might work for a few weeks.