Boat Buyers: Beware of Auto Parts

As I mentioned a while ago in this blog, I used to be an auto parts parts guy. I worked in a parts store and a GM dealership, and I can’t even remember how many boat owners came in looking for parts for their boats. Silly boys. Car parts are for cars. Boat parts are for boats.

It always began the same way: The customers would complain about how much the MerCruiser dealer wanted for whatever it was they were looking for. They never knew what year the engine was or any other relevant information it might take to get them the right parts, but they always insisted that because it was a small-block Chevy, they were all the same.

Any original or replacement alternator for a marine engine is required to have ignition protection.
Any original or replacement alternator for a marine engine is required to have ignition protection.

Well, that was fine for points or spark plugs or a water pump, but for everything else, all bets were off.

The lesson last time was that boat wiring in not car wiring. I’m bringing it up again because I’ve seen and heard of more cases recently where non-marine starters and alternators have been installed in boats. This is flat-out dangerous. Why? Because if you buy an automotive alternator or any electrical appliance that’s not ignition-protected, you run the risk of blowing up your boat. Without ignition protection, if for some reason you have an explosive air/fuel-vapor mixture in your engine compartment, and there’s a spark when you crank over that engine, it’s going to ignite the surrounding atmosphere.

Marine starters and alternators are ignition-protected, which means they don’t allow a spark to be emitted from the device. And that will keep you and the people around you from having a very bad day.

So, as you click through the pages of, and more importantly, as you go out to inspect prospective used boats, be aware that there are owners out there who have been either too cheap or too ignorant to install safe equipment — and you really don’t want to buy boats they have owned.


Boat Trader has plenty of  Buying and Selling advice, but also check out the hundreds of articles in the Boating section, with tips on everything from seamanship to maintenance, how-to, where to find replacement parts, and much more.