Hi,
I'm just tagging along on this post to keep everything in one place.
I've recently bought a Parker 21, which I'm keeping on a mud swinging mooring on Chichester Harbour, that has no working electrics. I bought along a motorbike battery to test things but nothing appears to work bar the VHF radio (although I have no antenna). My main priority is getting a solar panel to keep the motorbike battery charged and to sort out the depth sounder that doesn't appear to work. I was wondering if the transponder can be replaced from the inside (once dried out on the beach) or if it needs to replaced from the outside-in..
Also. from these images can anyone tell me which is the transponder and which is the log?

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As for the solar panel, there is a pre-existing panel that has been disconnected and there is no controller. Would any type of controller do and do I just connect the controller direct to the battery. Or is it better ripping it all out and starting with something like this?
https://uk.renogy.com/products/200w-12v-flexible-solar-marine-kit-w-20a-voyager-waterproof-charge-controller Any help/advice would be much appreciated.
Many thanks
Manuel (Galadriel)