starting and electrical 1985 Volvo 240 DL

I was wondering why my car doesn't like to start after it drives through
slush and rain. It just sounds like it's flooded and if it doesn't start it
has a terrible time trying to. If left for a while like a day or half a day
it will start once it's dried.

Also when I turn my on my lights it turns off my stereo and my gas tank and
cooling guages turn off too. Turning a signal light on can cut my power to
the stereo as well.

Finally my car won't start some times like it's completly drained from
something, and supposebly it's grounded and it not the alternator, I boost
it and it's good to go.

Thanks, any info would be great.

 

Is the plastic pan missing from under the front end?

Almost certainly a bad ground somewhere in the dash wiring.

??? That got a bit scrambled...