Mercedes: 93 500 sel heater fan, vent fan, turn signals

Question
QUESTION: sir i have a 93 500 sel.  when i shut off the engine the heater control panel goes to rest the red lite comes on and the fan runs. it will stay running until the battery is dead. can you tell me what i need to do to repair or replace to correct the problem. thank you tagman70

ANSWER: Don,
Which red light are your referring?
Is this a full force blower or an in the dash vent blower running at very slow speed?
Rob

---------- FOLLOW-UP ----------

QUESTION: it is the red lite on the rest button on the heater control panel. indicating the rest fan is running.it runs at slow speed just like the speed of the rest position. if you would like to talk to me my phone no. is  

Answer
Don,
There is a safety feature on some vehicles that cycles a vent fan when the emergency flasher are on. Injects fresh air into the passenger compartment to avoid carbon monoxide if snow bound etc.
There may be an issue with your flasher unit switch.
My 420 looses turn signals and flasher if the rocker switch is inadvertently left between the two setting. Your owners manual may relate something to this issue.
www.benzworld.com forums is another website that may have someone who has had this same issue.
Good Luck
Rob