I have a 1985 Mercedes 300cd 123. I am having trouble with my heat ac fan staying on. When I put my climate control on defrost and fan high and turn my ignition on with out starting the car I hear a clicking noise near the glove box. The fan comes on sometimes and sometimes it does not. The times when I turn my ignition on without starting the car and the fan comes on it works good in all the vent settings. When I go to start the car the fan shuts right off.