OK.....I ran some tests today, after the rain stopped. Again, the tester I'm using says the output of the current battery is just fine, at 12 Volts. I rechecked the connections and the sonar will still not turn on. So, I pulled the fuse link and tested the continuity of the blade fuse. Passed OK. Next I reconnected the sonar leads to my TM battery and presto.....the sonar turned on! So, apparently, my tester is either faulty or for some other unknown reason, the sonar just doesn't want to accept it as it's power source!

In any case, I've ordered a replacement 12V 8AH "Mighty Max" on Amazon.com. (Don't have to pay shipping and it'll be coming by early next week.) Same price as the original that I got at Cabelas years ago. That should solve my problem. If it doesn't, I'll be posting another reply! LOL! Thanks for your help guys. Muchly appreciated.