ome911

I have replaced my CCU 993-659-048-00 with CCU 993-659-048-01 on my 1990 C4. (Sorry David but I found a local RHD unit). Before the swap my windscreen & footwell controls were not working (windscreen went first then footwell but everything else works fine). The Porsche mechanic says the servos are fine and said the original CCU was defective. Anyway the problem has not gone away with the new CCU. So either I'm unlucky and have another dud CCU or there is another explanation. I'll check the back connectors again but nothing obvious on initial look. Any other connections I should be testing ?? Of interest the 1-19 pin connection has not been made as is recommended for newer CCUs in 89/90 models. I thought that this caused other problems not problems with the windscreen/footwell vent controls. Any thoughts welcomed.