[pgermond]

Originally Posted by patrickt

Remember that a capacitor will help suppress DC surges and make your "feeding voltage" more even and stable. Plus, a capacitor will filter out AC. If I put a volt meter and an oscilloscope on your car's electrical system, and I saw DC voltage swings of, say, 12.2vdc to 15.5vdc, and the scope shows AC current polluting the lines as well, then I would say "yeah, probably." The presence of AC is really one of those "gee, I would have never even thought of that" type conditions that can cause all sorts of goofy, hard to diagnose problems and failures with sensitive electronics. Here's a nice little video that outlines one.

Thanks for the clarification. For $40-50, I'll give it a try (can't hurt). Thanks again Patrick!