Dometic A/C reversing valve/ relay board issue

I have a Dometic A/C with heat pump that blows hot air in the cool mode.

I checked the wire at the reversing valve with a (tic tracer inductive type) voltage tester. There was no power in either heat or cool mode. I am assuming that the valve defaults to the heat mode when no power is present.

The refrigerant line going down into the cabin evaporator is warm and the line going to the condensing unit behind the fan up top is cool...(tells me there is nothing wrong with the compressor)

I replaced the relay board in the junction box (underneath the filter grill) 2 years ago. I noticed the relay terminal where the power feed comes into the relay board shows signs of overheating. The insulation on the wire is distorted and the plastic relay show signs of hot spots.

I am assuming that the reversing valve is fed by 110v from the relay board. I disconnected the harness feeding the rooftop and switched the stat to cool mode. The yellow wire that feeds the reversing valve shows no signs of voltage with a regular voltmeter. I checked the reversing valve coil for continuity and it reads approximately 450 ohms.

It appears to me that the relay board is bad again.

1) Is it ok to test this thing like this or do you need the bulb tester that the manual calls for?
2) Does it sound like the board is bad to you guys?
3) The unit is in a 98 Alpenlite and looks original...do you think it is worth another $75 board or just replace the whole unit?
4) Is the reversing valve 110v?
5)Anything you think I am missing or should check?

here are the specs;

1998 Alpenlite
Duo-Therm w/heat pump & analog stat
Model #59146.621

thanks for your time and your knowledge!

Bruce