Electrical issue with my 1990 300D
I have a 1990 Mercedes Benz 300d turbo diesel. Problem started with glow plug light coming on and off. I replaced the glow plug module twice so far and it appears to work for a while and then the problem comes back. maybe some kind of electrical issue. I am on my 2nd alternator. While the engine is running the glow plugs will come on at times and also a brand new alternator is putting out low voltage. Any ideas of what the issue might be or where to start looking?