I'm a new owner of a 1987 345.
The air compressor doesn't come on when the engine is started. The bags are at 7".
Where do I start with this fix? The prior owner had it sitting for 5 yrs.
Welcome to the forum, you are in the right place. I would start with a multimeter and test the connections at the compressor when it should be running. You might have a Schrader valve curb side between the rear wheels, if so you can check pressure there and fill the system in a pinch. If not, there will be a valve at the bottom of the air tank, it lets you drain water from the tank and can also be used to check pressure/air up.
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