I received my new Penguin AC to install in the front. Now... for some reason, I am only getting 90 volts to the AC. I checked the breaker and even replaced it and also cleaned off all contact points, but still only get 90 volts. The AC needs at least 120. Does anyone have any insight on what could be wrong?

I had a similar issue a few years ago. At least the connector was accessible in the reefer exterior compartment. Fortunately, the Barth wiring diagram was for 120VAC, and it took only a few minutes to locate.

Rusty and all,
I checked all connectors I could find leading up to AC. All are fine. The weird thing is it puts out 90 volts at the AC, which will not turn it on. I hot rigged the new AC and it works fine. I am in a bad way because we are leaving in a few days for Colorado Springs. What would cause a voltage drop of 30 votes from the breaker box to the forward AC?

If you have 120v at other places, it has to be a bad connection somewhere....a bad connection can cause a situation where you read 120v but the voltage drops to zero when a load is put on the circuit...
If you have access to the connectors, measure the voltage with and without a load (a lamp will work good... Turn switch on and off to change load) and find the bad connection ... Measure on the load side of the connector.... Voltage could be good going in but not out of connector... Start at the breaker... Although the lamp won't light, the voltage will change at and after the bad area..120v reading with and without load is good area... Keep trying ...and report back...

Having verified full power out of the breaker, it has to be a line connection somewhere. Those connectors Barth used in the later coaches are really poor, I'm surprised we haven't seen more fires…

Your 90 volts is more like a bad connection than a broken wire, so you need to find out why or have a potential fire on your hands.

Worst case you may have to run a new 120 line to the AC from the breaker. Good luck.

I recently had to replace a duplex plug in my coach. I was disappointed to find that the OEM had no terminal screws, just push in connectors. These are the cheapest plugs of all, I'm surprised Barth went that cheap on the 120V wiring. The 12V Barth stuff is generally very robust, my GM chassis 12V not so much. I have now replaced all the OEM plugs with higher quality.

Thanks for all input. Believe I will run new wire to the AC from the breaker box. Biggest problem is fishing it through the walls and the ceiling where the AC is. We will be leaving for Colorado Springs Tuesday, so its a project when we return at end of May.

One possibility is a poor ground/negative connection. If the ground side is not well connected you can have a situation showing 120VAC with nothing connected, a drop to perhaps 90 with a light bulb loading the circuit and a further drop as you add additional loads. I would not expect the circuit for the AC to have an additional load so probably is not the case but it might be worth checking the resistance of the circuit with the breaker off. If there is anything other than an open circuit the choices get perplexing.
Keep us posted.
Tim

Check voltage from hot side at ac to hot side of breaker while under load. If bad connection on hot circuit you should see 30v. Do the same on the neutral side. A 30 volt drop has to be getting a connection hot some where. Good luck.

The clear flat connectors are where I would suspect first.