Probably going to have to buy a new head.
However some folks have been able to get them working by putting the batteries in backwards for a few seconds.
Also take the board out of the head and reflow the solder on all of the switches.
Dealer probably won't be much help unless you have the programing numbers from both key heads.
If you buy a new one from other than dealer make sure to get the numbers or it will be decorative.
PS:
Keep that 2000 3.2 in good shape. It is very rare.