Basically, what needs to be done is sealing the connection of all the wires at the distrubtor cap, ignition coil and at the spark plugs.
- Sealing distributor cap and coil
Use silicon sealer around all the spark plug wire connections and where the cap and distributor meet. This may make it hard to get the cap off, i suggest that you take the cap off while the silicon drys so that the cap and dist. aren't glued together. When the silicon is dry it is still flexable, so it can make a good seal even if you take the cap off for tune-ups. If the cap and dist are stuck together then the silicon seal might be damaged when the cap is removed. The condeser wires should be globbed with silicon as well.
There are also "waterproof kits" consisting of a molded rubber boot that seals everything, but i've found that these make it nearly impossible do get the cap off. I don't know how well they work at keeping water out.
Again, for the coil, use silicon to seal the plug wire and globs around the + and - 12 volt wire connections
- Spark Plugs
This was the biggest problem that i was having when i stalled in the water crossings. when splashed water hits the engine and makes steam, it gets between the plug and the connector and shorts it out. The whole rest of my ignition system was perfectly dry.
What to do? Well, the late model Super Beetles have special boots that fit between the plug and connector to keep the steam away. Go to the parts store and get some, now!
- Other
This is worth mentioning as well...
VW's are notorious for developing rust holes in various areas (you know what i'm talking about!). If you find yourself in a pit of water that goes up to your door handles, you will find that the water will pour in like Niagra Falls, shorting out your voltage regulator in no time at all. Another source of water entry is the rear heater ducts. Mine are wide open to the outside still, i have a nice build-up of mud festering in there.
So, if you want to see how well your baja will float, seal up the body first.
I have installed a modifyed version of the "waterproof kit". One was on the car when i got it but it was so old and brittle that i had to cut it off to get to the points and such. I reinstalled it but i cut off the lower portion so it only comes down to where the cap meets the distrubutor. I also wrapped electrical tape around all the joints where the wires go into the boot and i wrapped every spark plug wire entirely with electrical tape as well. I tested this while the engine was running by spraying everything with a garden hose. It didn't even think about shorting out.
UPDATE - Make sure your cv boots are in good shape because if they let water and mud in, your cv's will fail, right when you don't want them to.
when things get really out of hand you should tote the ever popular bilge pump...
