first thing: always check your fuses.. look into your owners manual. :-)
I think I've had 14 bmw's in 4 years.
2 IX's -sold and parts
2 325i 4 dr - sold
4 318is all white - sold and parts
1 87 325is red - parts
1 89 325i vert grey - parts
1 90 325is white - keepin
1 87 325i vert -red - keepin
latest addition 1 88-325is red - parts
latest addition 1 89-325i vert - white -fixin/sold
latest addition 1 92-318i vert - blue - parts
latest addition 1 87 325is blk - parts.
latest addition as of 2013-Gold 87-325is auto! it's a keeper!
I assumed that the rear defrost wires in the hardtop glass shared a circuit with the rear defrost blower (which was working) as they are actuated by the same switch. However I guess it's possible they could share a relay but be on unique fuses.
Anyone wise as to how the hardtop wiring works? which circuit is on which pin? where the ground is made?
Although I hope it is a simple as fuses, I'm rarely that lucky; I'm willing to bet I'll be chasing a break in the circuit with a multi-tester.