Biodegradeable wire was 95 to 97 from what I have read. However I would check the now 25-year old harness carefully in the high heat areas, as it might well be extra crispy by now even if it is normal wire.

Evaporator trouble is highly likely, any 124 up through the 210s has this problem.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech