I think at this stage we need to know if relay power is getting to the starter solenoid when the key is turned to [Start].

How can I test this without a volt meter. Doesn't the radio going off and dash going off when I turn the key mean that power is being diverted to starter selenoid?

I'm not going to give you an electronics lesson here. Your switch may or may not be bad. Without testing you just replace it and keep your fingers crossed that it fixes it.

A test light would be better, but either way testing needs to be done and tools are needed to test.

Some cars cut power to lights and accessories when the ignition key is turned to [start] and then return power to the lights and accessories when the key is released. I don't know off the top of my head if yours is one of them.

Is a volt meter adequate for testing. My friend has a volt meter he can bring over

Yep, that will work.

At the one minute mark take note.

Hello,
So we tested the cable going from battery to starter and there was no power. There is a fuse in line from positive terminal to starter (near the battery end ) . The 275A fuse appeared dead. We replaced it with a 250A fuse (as 275A was not locally available). The 250A fuse burnt out as soon as I tried to start the engine. Would this 25A lower on the fuse cause it to burn out or do you guys think it is something else ?

Thanks

Sounds like the starter may be shorted.
Can you hit it with a hammer or something?

Yes I can hit with hammer..but what will that do? Won't that just break it. Would it short by the car just having sat in the cold for a couple of days?