Hi David, there's a guy on the US Corvette Forum
"
http://forums.corvetteforum.com"
who is THE guru of vette aircon - Post or IM him - Sun CR .
He was so helpful to me I established email contact with him - he bought his 89 new and so has a wealth of C4 knowledge - he also likes doing things himself so they get done properly - does that sound familiar to anyone ?
(I just remembered that he's away on holiday first half of July)
If you have climate control , C68, then I've learnt a bit about that, had my head unit completely apart and fixed many things - intermittent display - buttons not working etc.
I've replaced my blower also and found there is a fuse in the engine bay which, if blown, puts the blower on full.
The blower module is on the bottom of the evaporator box, not the top as in LHD, so gets wet, corrodes and is v hard to remove.
Let me know if I can help, I'm away 5th -15th July - going down to the Corvette Classic in Brisbane.
S'nut