Painting - Removing paint from stained wood

I have a 94 Nissan Sentra which repeatedly is failing alternators. When the Alternator is installed everything seems fine, charging levels seems fine. Very regularly at about 6 month intervals or about 5,000 miles the alternator fails and I install a rebuilt one. Have been through 6 rebuilt alternators in the past 3 years. I'm finally convinced, there is a strain on the elctrical system somewhere else, but the mechanics say everything appears okay when I have it checked. What can be causing these premature alternator failures.

I am purchasing a home that all the wood is painted. The trim, kitchen cabinets everything. I was told that once wood is painted it is impossible to get the color out of the grain of the wood. Is this true and is it difficult to remove the paint and restain the wood. By the way I am hiring a painting contractor to do the work.