I have Lowrance Elite 4 on the kayak. The fish finder have not been used in a while. When I tried to turn it on nothing happened. The battery was charged. When the wiring was checked there was a voyage drop to the connector that screws into the back of the unit. The connections in the wire were redone and the voltage at the screw on connector was 11.5 volts. Still nothing. I checked at a local shop to see if they had a power supply I could check the unit with. They did not. They said the connections go back and I should try putting di-electric grease on the connections. That sounded reasonable to me so I bought a small tube of di-electric grease and put it on thinking it would bridge any gaps. Still nothing. Turns out the di-electric grease is silicone. Silicone is an insulator, not a conductor that I thought would bridge any gaps due to spread connectors. So now what do I try next?