New Starter issue

[whaler23]

I recently had a tech replace my Cat Starter on the port engine. It has an integral solenoid and in addition he replaced the relay mechanism mounted near the starter at the back of the engine. Started boat up this weekend and all was well. Moved boat to bulkhead to wash down. Went to restart port engine and it began to spin/whine but no engagement or start. Key off made no difference. Pulled the hatch killed all power. Turned power back on at batt switch, immediately whining again, no starter engagement. Turned power back off, banged on relay with hammer. Turned power back on and starter worked fine. Does this sound like a bad relay? Why would it spin the starter (or was it just the solenoid) and not engage starter. Started fine two additional times. Any tips appreciated.

[Boatsb]

get it checked out. If it is new or a new rebuild it will still have a warranty. I had a rebuild hang a brush in the first month I had it. They repaired it and checked it out again no charge because I brought it back in. Had I waited I would probably had to pay for the service.

[Blaine Thorpe]

Scott,

If it hppens again, I would get the volt meter out before banging on anything and check the voltage at a few spots: 1. to the relay, 2. coming out of the relay, 3. at the starter solenoid from the relay, 4 from the starter solenoid to the starter.

The relay is in the system to take the starting load off of the start switch. Once the relay is energized, it sends current to the starter solenoid. The starter solenoid should pull in and engage the flywheel before the internal contacts in the solenoid connect and send the current to the starter to start it turning.

It sounds like the solenoid is moving to make contact to get the starter spinning, but not engaging the flywheel. I would check the voltage at each spot to help figure out what's going on.

Could be the relay or solenoid.

Blaine

[whaler23]

I emailed my mechanic and will let him look at this, he installed it last fall before I winterized. Hopefully it's still in warranty... I'm also going to run a new cable from the battery over to the starter, it's looking a bit old and I'd rather replace to rule out the cheap stuff first.

[Trojan]

It sounds like it could have been low voltage. It is possible that the contacts in the relay were dirty, corroded and the large amp draw at first, welded a small bridge on the contacts. It was not a big enough bridge to carry the heavy load of the starter solenoid so in turn the starter motor turned at a too slow of speed and the solenoid failed to engage. I don't know how your perticular starter engages into the flywheel. But it had to be something close to it. The relay is the only thing that feeds power to the solenoid and starter motor. Should it do it again. I would do a little voltage checking.

BILL