OK I am at a loss. Last week I go to lake. Put in and start the motor with no problem (Took a couple of cranks). I run across the lake for about 30 minutes. Stop and fish for about an hour then go to crank the big motor and it does not have enough power to turn the motor over. Troll back to the dock and still have enough power to raise the tilt but no way will it crank. So I go get a new cranking battery and put it on a charger all night. I head back to the lake this AM. Back the boat down and lower the tilt. Hit the cranking battery and DEAD again. But this time the Tilt will not come back up either it is DEAD DEAD. So I pull the cranking battery out and move a trolling Battery over to get the tilt up and then pull the boat out. I put all the batteries back in their correct places. Now for some reason the cranking battery is fine full cranking power. Back down start the boat and run around the lake a while and everything seems normal. I can kill it and restart no problem. Now here is the only thing that is different from the hundreds of time I have taken this boat out. I bought a new Anchor Light (One ion the Rear) and both times I have had this problem that light has been hooked up. It was however not even turned on the Am but was the first time I had the problem. Any thoughts on what the problem might be? Could the new light have anything to do with it? I am not electrical at all so I need some help. Thanks

Got a volt meter? If so, turn EVERYTHING off. Disconnect the positive leads at the battery and place the black lead from the voltmeter to the battery and the red lead to the accessory cable you disconnected (do not include the outboard starter cable). read the meter. With everything off it should not read any voltage. If it does, unwire your anchor light and repeat the process. Good luck!

It sounds like you just had a bad connection at the battery. Is everything working like it should now or are you still having problems?

i agree with high just clean and tighten you connections

if it happens again use a volt meter to check voltage at any ground and power point past the battery connections and then again at the posts {not the connectors} on the battery without disconnecting anything if the voltage is more at the battery just try cleaning your connections but I would do that right now anyway. Go to a parts store or electrical supply like radioshack, parts stores sometimes sell small packets of what they call battery grease same stuff its clear grease, and get a tube of DIELECTRIC GREASE {not regular grease} and cover the terminals connectors and battery posts with it then hook everything back up this dielectric grease will keep everything from getting corroded again. Reapply the dielectric grease anytime you disconnect the battery and use it in all the connections in the boat too to keep moisture out of the connections.

2nd when you replaced the battery you tightened.

Thanks Everyone. Took the boat out yesterday and it was working fine. Hopefully it is not waiting until I get about 15 miles from the dock and then decides to do it again. Really makes me nervous.

Sounds like it was a coincidence that it happened when you installed the new light. You probably fixed the problem when you disconnected the battery cables and reinstalled them.

just for grins pull your cowling off and check your connections under there also,just to be sure it was not a loose ground on the block...or loose positive cable to starter motor..