Battery/electrical problem starting 2500 SCR

[CH47TF160]

Hello guys,
First time boat owner here with an electrical problem. I searched the forum and found similar problems, but not this one in particular. I have a 2003 2500 SCR. During the sea trial, everything worked fine. The second time we used the boat, there was a clicking sound while trying to start the motor. I switched to the other battery, and it started right up. After we got back, I inspected the connections on the batteries. There was slight corrosion on the one that wouldn`t start the boat. I disconnected it, cleaned off the corrosion, and tried it again……same thing. Since I didn`t know how old the batteries were, I replaced them. The previous owner had 2 cranking batteries installed. When I replaced them, I put in a cranking, and a deep cycle. The clicking was still there. When I tried starting the boat to move it out of the marina I had it in for Hurricane Irene, I got the humming sound from both batteries. On the 3rd attempt, the battery that had previously worked, started the boat, and I was able to put it back into my regular slip. All connections on the batteries are tight, as is the connection to the starter. Could the problem be in the battery switch itself ? Also, the remote spotlight and the gps will not work now. Not sure if that`s related or not. Nothing on the panel is popped. Any help would be greatly appreciated.

Tom

[CountryME]

Tom, I would check the slave solenoid. It can give you intermittnet issues such as you describe.

[seapuppy]

It sounds like a corrosion problem...the hard part is it's electrical and electrical problems are elusive..the best thing to do is check all connections in the circuit for any corrosion...repair and clean any that you come across...although connections may be tight...it can build resistance once corrosion starts up....so..if I have this correctly you bought 2 new batts....and you still have the starter solenoid clicking when you turn the key....be sure to check connections on the ignition key itself as well as down at the starter and the harness plug on top of the engine...when you clean the connections...smear some dielectric grease around each pin or connection.....this will help slow down the corrosion process......


let us know what you find..

SP

[shrew]

Another thought and troubleshooting methodology would be to try and isolate variables. The positive lead from Batt. 1 should connect to the post labelled Batt 1 on the switch. Like the positive lead from Batt #2 should connect to the corresponding post on the switch labelled Batt 2. You can discconnect the lugs from the battery switch and swap them. Now Batt 1 is connected to the Batt 2 post on the switch and vice versa. Now start the engine on Batt 1, and then Batt 2.

1) Does the problem follow the battery? So if, for example, Batt 1 started fine and Batt 2 did not, then if it were a battery or battery cable issue, then after swapping the issue would be occurring in reverse. This would indicate that the issue was 'upstream' of the battery switch (between the battery switch and the batteries.

2) Does the same issue occur regardless. Then I'd suspect the issue is 'downstream' from the battery switch.

Another thing to keep in mind, some battery switches are wired so Batt. 1 is engine and Batt. 2 is house. In some configurations, the boat may only be started on Batt. 1, while dedicated house runs on Batt. 2. this is how they wired my boat when I bought it.

Another thing to consider is the connection to the starter itself. I had a corroded connector on the starter that started coming loose and it's behavior is very much like what you described.

If this is a solenoid issue, then you should be able to theoretically jump the solenoid to bypass to verify if that is the issue. Don't confuse the solenoids on the drive trim pump with the starter solenoid. They are different.

I'm not sure if this helps, but it's a start.

[CH47TF160]

Yes, electrical problems can be tough to trace. Thanks for the advice and input everyone. I`ll try those things out and see what happens.

Tom

[CH47TF160]

Sorry for the delay in getting back, I`ve been working alot. I think I have it narrowed down to the battery switch. I tried taking the switch apart, but the assembly will barely move after I remove the screws holding the plate. For the switch itself, there are bolts and nuts holding it to the plate. I`ll need to get a mirror in there to actually swap the positions and see what happens. It is starting everytime on the number 2 position at least. Thanks again for your input everyone.

Tom