Reversed Neutral/Hot question

Agree that the neutral is suspect. With a digital AC voltmeter with test leads measure the voltage as you turn on the heater and you should see the problem.

Expect 120V hot to neutral and 120V hot to ground and 0V neutral to ground within about a 5V variation when working correctly.

You can buy a voltmeter for $10 and report your findings. You can eliminate the pedestal by trying another pedestal.

Is your power cord end hot?

The reason I ask is a warm cord end indicates a loose connection, and it can have a 15 volt drop across the cord end. Mine did on a hot day while I ran the A/C. 13 amps X 15 volts is about 150 watts dropped across the plug end, heating it like a toaster element! Your voltage drop might not be as severe as mine was.

If the cord end is hot, or even a lot warmer than the air it is in, you might need a new cord end or new plug for the wall. Either is about $15 - $18, so might as well replace both.

Fred.

I would check the neutral connections.
If you are using an adapter, check the cord bodies to see if any are hot. If it is, that could be failing.

This is a 30 amp rig.

http://www.noshockzone.org/

Is this a 30 Amp or 50 Amp MH?

I would say there is a problem with the neutral. It may be corroded or loose connection on the buss work in the 120 volt power distribution panel.
Is your rig 30 or 50 amp?
If 50 amp are you running through an adapter?

Use a voltmeter instead. The meter could be giving you a false reading due to some minute leakage current.