Purchased a 1990 500 SL 2 years ago and have Thrown Countless dollars Into repairs and Maintenance . I have One outstanding major repair to complete and need some help. Previous owner cut and plugged and rerouted all hoses and by-passed the heater core for some reason - Could be Blocked or Leaking core, dont know will tackle this problem as i get to it . If Blocked Ill try compressed air to clear, if leaking I have a major problem in replacing. I have a feeling that the heating control unit was bad and ran constant heat in Florida. Car is now in the North and its a bitch with no heat. I have already purchased a used Heater control unit and new mono-valve and replace all items at once.. I'm trying to find a layout and proper routing of all heater hoses So I can reconnect to determine if core is bad. Hose at the Mono valve disconnected and capped . Hose at fire wall driver side was cut flush no cap . If anyone has schematic of hoses and hose part list it would be appreciated. Could not find any post addressing this issue
Rich ret9852@yahoo.com