a/c will not blow cold 1987 bmw 325i conv
Your resistors may need cleaning. They are located in the firewall behind a wide panel. Remove the panel and the fan to expose the resistors, which look like a long spring. In the E30's they will eventually become covered with filth. Use NON-FLAMABLE electrical cleaner to remove the buildup and you should be good to go, if you don't actually have a refrigerant leak.
You are talking about loosing refrigerant right? If so have you converted the system to a R134a system or are still running R12?
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