electrical dilemma

[Rob 8043]

I hadn't used my mariah 202 for 2 years and decided to have it serviced etc. I contacted a new mechanic and made arrangements to have it serviced. I explained to the mechanic that I knew the batteries were dead and that I would replace my batteries (dual system) and he said no problem he would use his to make sure everything was working, there was 1 dead battery in the boat at that time.

He calls me during the day it was being serviced and asked if I had a kill switch because he could not get the boat to start. I don't and explained that to him. At that time there was 1 dead battery in the boat and he had added a good battery. He called me later and said that due to my set up he had to put 2 good batteries in to start the boat.

Question 1: in a dual battery set up with a perko switch can't you simply set the switch to the good battery and everything should work?

The story continues. I pick up the boat take it to storage and but another battery so now I have 2 new batteries and install them. I have no power to the ignition, or any of my accessories but the out drive has power.

I take the boat back to the shop. He explains that it probably is the relay on the starter ( mercruiser 350 mag with bravo 1 outdrive) and that he will diagnose the proplem and get back to me.

It turns out that the relay is blown it is replaced and everything is working now.

I am concerned because in 10 years of owning this boat I have never blown this relay before and do not want to do it again especially if I am out on the water.

Did I do something to cause the relay to blow when I connected the batteries? The mechanic speculated that having let the batterries go dead could have caused a surge when I hooked them up causing the relay to blow.

I wonder why the mechanic was able to start the boat by putting in 2 new batteries, but when I put my 2 new batteries in, the relay blew.

Sorry about the length of this post, but I would like to learn from this experience and I felt that this was the forum to get answers ( this is my first post). Thanks in advance for your insight and help

Rob
Las Vegas, NV

 

[maxxman04]

Re: electrical dilemma

relays generally last quite awhile, but as they are an electrical item, they're still subject to the same electrical gremlins as the rest of system. a surge may cause them to fry, hooking battery cables up wrong might cause this. also, time and sitting with no use. if parts are allowed to sit with no use for a length of time, it's possible a small bit of rust or corrosion may have gotten into the relay. 10 years is a pretty good life for that relay, tho some go longer, some fry sooner. if everything is ok now, works great, i wouldn't worry. at some point, every part will fail, whether it's a few years, or a couple decades.

 

[gadget73]

Re: electrical dilemma

My drive relays stop working properly every spring. I have to bump the buttons a bunch of times to clean them off, then they work fine. The drive relay is identical to the starter slave relay.

However, that said, I think its more likely your problem was a bad connection at the starter solenoid, or at the big round plug on top of the motor. Some boats have a big fuse on the side of the starter that feeds all of the stuff at the dash. If thats bad, or the connection is crudded up, you get zilch. Drive trim power is often direct off the battery, so that explains why that works. The only thing the starter relay does is provide power to the starter solenoid. When it doesn't work, you get "click" when you hit the key, and no spinny-spinny on the motor. All the other stuff should be working normally though. If your guy replaced the solenoid on the side of the starter, simply unbolting the cables and re-attaching them is most likely enough to clear the connection up and fix the problem.

Just speculation of course. Haven't had any experience with that particular boat.

 

[Bondo]

Re: electrical dilemma

the relay blew.
I am concerned because in 10 years of owning this boat I have never blown this relay before and do not want to do it again especially if I am out on the water.

Ayuh,.... Do-Do Occurs,... Things Break,....
You got 10 years outa the old 1....