C30 Wiring
Hi Anita, I also have an '89 C30 and have done a lot of rewiring on it. I changed my cables by removing them, taking them to a battery shop and having them duplicated. Sorry I dont have the length measurements. I went from size 4 to size 2. The larger diameter wire was much stiffer and harder to bend. The only place this was a problem was on the back of the selector switch. Going to 0 or 00 might be even more difficult to get the wire in there to make the connections. The easiest place to oversize is from the engine block to back to the batteries. You may also want to increase the size of the ground wire from your electrical panel to the engine block as all panel circuits go thru a 10 gage wire to the block. (And it's not even a tinned marine grade wire). Remove AC power from the boat before doing any work in the panel area. My wires were so bad that when I tried to pull the connectors off of the backs of the rocker switches that the wire came out of the terminals before the terminals came off of the switches. I ended up buying a double crimper and replaced all the crimpped terminals with marine grade. Also while you have the AC removed from your boat you might want to pull out all the plug-in type electrical outlets and inspect them. I was surprised my boat hadn't caught fire from the condition mine were in. They are easy to fix, though. Just clip off an inch to get back to good wire and attach them to a new outlet (about $3 ea at a hardware store).
