starter solenoid failures

Hello All,

Over the past 10 years or so, I've had 3 starter solenoid failures. The first two fused in the on position. When one fused, I thought it was kind of odd, but when the second one fused, I figured something was not right. After replacing the second one, the marina recommended I replace the battery cables, which I did with some pretty heavy marine wire with sealed and soldering ends. For the past 3 or 4 years, no problems. This past weekend, I had another one fail. This time, it's not fused, but will not engage. I have power from the ignition switch and full charge on the battery. If I jump the battery and starter leads with the key in the on position, it starts right up.

These have all been from the marina, so no cheap auto parts stuff. I've checked and cleaned all the terminal connections and I always clean the mounting location of the solenoid. And I do understand the boat gets started a lot whenever we're switching skiers, but 3 to 4 years seems pretty short life span.    

Any one have any ideas?

Andy

It's just a standard Diehard that fits in the original battery box in the floor. It's not a deep cycle or gel-cell or anything fancy.    

To clean the terminals, I have a wire brush that's originally for cleaning copper pipe fittings. It fits right in the terminal and then use a little sand paper on the battery post. I also put a little grease on the post before putting them together.

The first two failures were when the contacts fused together and that is when it was recommended to replace the battery cables and make sure all the connections are clean. After doing that, no more problems with the starting staying engaged. This most recent failure is the opposite, as it will not engage. I wonder if it's just a coincidence.    

I've been getting the solenoids from the local marina so I was sure they would be marine grade and I was also hoping they would be of good quality. I don't know the brand as the boat is at the cottage. DIM has then for $28, which is less than the local marina, so I'm going to order one from there and see how it last. I might actually by two.   It's sort of like having an extra impeller around. I call it the weekend saver.

Any other suggestions, I'm all ears.