Land Rover Repair: 1997 land rover discovery, land rover discovery, alternator wiring

Question
My battery overheats occasionally and it smells bad. I also have the tach and radio going weird. The tach stays normal and than suddenly drops out to zero at the same time the radio will go off and than on again as the tach goes up. I have installed a new alternator-I have checked my ground wires from the alternator and i even removed all electrical accessories to minimize any possible wiring problem.

I continue to have the same problem. I also forgot to mention as the tach is dropping to zero you can see a slight dimness in the headlights if they are on. With all these things happening to my surprise the engine runs like a fine tuned clock. It's my first land rover and I have also learned that it was driven in lake from the previous to previous owner. I see no signs that water entered the cab though.

Answer
Your symptoms point to a problem with the alternator, or the alternator wiring.  In particular, you may have a bad diode in the alternator, putting too much ripple out.  Or else the voltage regulator has failed.  That's usually the reason for battery overheating.