Hello Benz Enthusiasts; I recently purchased a 1991 350 SDL.Love the car and i have every intention of keeping it until the engine gives up the ghost.That shouldnt be for another 300k.Have 90k on it now.I have an issue with the radio.The question is why the radio displays E 2 and then turns off when ambient temperatures are 50 F degrees or less.Anything above that temp.,radio works fine.Maybe i need to get the radio a jacket,. Does anybody have any ideas?My next question is where i can purchase a service manual for this vehicle.