Ok... Took apart the rear seat and took a look at the rear heater, have some
solidified (white powdery stuff) coolant on the fins and around one of the
hoses but no sign of liquid anywhere... I tried running the heater to see if
I smelled any coolant or saw any leakage, but the motor will not turn on...
What's an easy way to test if I have a bad heater or bad switch? 

Thanks,
David / NJ
Former owner of a 76 Westy (sniff, miss ya Wanda)
New owner of an 85 Westy Weekender Wolfsberg