air conditioner not working, lights dim, refrigerator not cooling

[gingerbred_austin]

After setting up the camper (2011 Zinger 30KB) for 24 hours, we went to check on it and hook the water up. Before getting to that, we noticed the A/C wasn't working. Lights were really dim inside too. Fridge wasn't cooling like it did day before. Turned off A/C, then waited a little bit, turned it back on, and it blew cold for a little while, then stopped again.
We had a master electrician install the 30 amp outlet right at the pole for us (next to our breaker/meter). It was providing ample power. Husband turned off unit overnight, and then turned on this morning, and by afternoon it was still working right. I know the battery at the hitch is dead (or close to it), but should that affect the lights, fridge, and A/C? We're replacing all interior lights with LEDs to help power draw decrease. Need to get this set up and ready since our lease is up on our rental next Monday. Thank you for any help/ideas!

[CampMacKay]

A dead battery could be the problem. The fridge requires 12v to operate, the air conditioning thermostat also requires 12v and the lights are 12v. A fully charged battery is a must.

[harley]

Sounds like the 15a breaker for the "converter" is either off or not working ...or the converter is puked. Check for 120 v at both sides of the converter breaker.

[harley]

If converter is no good , hook up a battery charger to the battery on the tongue to keep it topped until you figure what is up...just plug it into a 110 v plug on outside of trailer.

[gingerbred_austin]

Thank you all so much! So we started with a brand new battery, and all was well until this morning... LP monitor was dead, lights were dimming again, etc...
Husband read the power on the 12V battery and it was at 7 volts. He hooked up the batter to a charger (we had a second battery ready just in case). So, we now will check the converter fuse, if there's power on each side, and see if it's a fuse or the converter. Will update when we find the culprit.

[gingerbred_austin]

Now the question is: how do I check the input and output of the converter? I unscrewed the side panel that shows the back of the converter, but even after 6 YouTube videos I still don't understand how to check (or where) since there are a ton of wires going into and out if it.
Also, where are the fuses? Are they the two 40 amp?

[Lloyd]

If you have a volt meter, you should be able to check to see if the converter is working.
Unplug the trailer from AC. Check what the voltage is at/on the battery. Plug the trailer back in to AC. Check the voltage again at the battery. If the converter is working, it will show more voltage when plugged in.

[gingerbred_austin]

Ok- our battery has been losing charge each night, then we switch it and recharge the battery via a charger at the pole. So the converter is most likely (99%) kaput. I'll check fuses too. Fun times! �� Thank you everyone for your insight!

[Lloyd]

If you check it the way I said, the meter should read approx. 13.6 volts when plugged in---if the batteries are good.
Unplugged it should read approx. 12.5 and go down as the battery depletes.

[MartyinSC]

Originally Posted by gingerbred_austin

Now the question is:
Also, where are the fuses? Are they the two 40 amp?

Those two large fuses are best checked by first pulling them out of the unit, then checking continuity with an ohmmeter (one of the settings on a multimeter) to make sure current can go through each. As a note, these large fuses are designed to "blow" when the battery is installed backwards.

[gingerbred_austin]

Both 40 amp fuses are blown. So we'll replace those and hopefully be back in business!!!

[MartyinSC]

Originally Posted by gingerbred_austin

Both 40 amp fuses are blown. So we'll replace those and hopefully be back in business!!!

Remember what I said will blow those fuses! On my Crossroads battery connection, the Black lead is positive, the White lead is negative.

[gingerbred_austin]

Fuses checked and both no good anymore. We thought back to when we were picking up trailer and we hooked up battery wrong at first. After fixing, we kept hearing a whirring sound near where converter is. Every time it was hooked up to battery. Must've been converter unable to do anything for battery since we blew the fuses.
After we replaced fuses, We checked the battery with AC and it was 12.8, unplugged it went down to 12.5 quickly. Yay! Back in business and didn't have to replace converter!
Thank you all again.

[Lloyd]

Good deal!!
Glad you have things working, and thanks for reporting back.

[MartyinSC]

Glad to hear! Sounds like your proficiency with the voltmeter paid off!

[harley]

Now ...paint the end of the positive wire and connector with RED nail polish and paint the terminal of the battery too so you will not forget next time ...