Thanks Geoff, didn't realise that it won't show any resistance. I had connected to a 12v supply first and checked that all the electrical connections were ok. The whole unit was dead - that came as a surprise! Having said that, it looked like the spoiler had spent a lot of time in serious dampness - had to use rubbing compound to get the cr*p off. 
Looked well when I'd finished apart from the dead LED. 
 
Shame there doesn't seem to be much 626 spoiler stuff on eBay  
