Brett
Do you have access to a test lamp or a meter?
You probably will find the problem is a corroded or dry joint. A dry joint is a soldered joint where the solder was nit hot enough to fully flow through the connection and may look ok but there is no conductivy through the joint.
It is just a matter of hooking up one side of the test lamp to the negative side of your battery and turning on your sounder and chasing the connection through until the lamp or meter doesnt indicate voltage present.
If you dont have a meter of test lamp you can just use a length of wire and hook it up to the positive terminal and chase the connection through only this way when you get past the fault the item will start to work. Ideally this wire should be fused in case you earth it out. If you cant fuse it an alternative is to use stranded cable and seperate a couple of strands and use them for the test probe and if you accidentley short it out you will only melt the strands.
Do not use close to the battery if you have recently been charging it as it is possible to explode.
Better still see if you can con a mate to check it out for you.You always seem to ne helping others surely there is an ausfisher in your area who can help.
It is a bit hard doing things by remote diagnostic.
Cheers
Ray
Do you have a fuse panel as sometimes the fuses get corrosion on them.