Is my alternator going?

Connected to shore power, it sounds more like a failing battery.
Take it to your local auto parts such as AutoZone or O'Rielly's and have it tested.

All converters (not alternator) are not equal, so hard to say how normal yours is. If you have not heard the converter fan running often, in the previous several years of ownership, then you may have an issue.

If you have a digital volt meter, what does it read at the battery posts, with the converter in use. A reading of 13.2 is a float charge, and anything over 13.6 is indicating the converter is charging to catch up.

You say your camper is at a place with available shore power, so if plugged in, not disconnect switch shut off, your battery should be at full charge, each time you return.

If you are not plugged in while away for a month, yes your battery is depleted, may be damaged.

Jerry

schlep1967 wrote:
Your camper does not have an alternator. It has a converter. It converts A/C voltage to D/C voltage. Yes the fan runs when it is working properly. You will notice that the more 12 volt lights or vent fans you turn on the louder the fan will get. Totally normal.

Ok, thank you.

I have all LED lights and I'll have the TV on in the evening but I'll hear the fan running all night when the lights are all out. I guess fridge is running.

My understanding is the Coleman TT needs a 12v battery for the AC to run, which it runs a lot in the summer. My feeling is the battery is getting depleted while I'm not using it then try's to get to full charge the 3 days it's plugged into the 30amp outlet.

Your help is very appreciated. I'm new to this.

Your camper does not have an alternator. It has a converter. It converts A/C voltage to D/C voltage. Yes the fan runs when it is working properly. You will notice that the more 12 volt lights or vent fans you turn on the louder the fan will get. Totally normal.