This is such a big problem on the early 1977 to 1979 123 240D, 300D, 300CD and 300TD diesels that I decided a good replacement kit was in order. Often I find the main feed wire loose or frayed, the fuse box cracked or melted, and the fuse connector points corroded or loose. All this means loss of current to the critical glow plug circuit. And on these models you need all the current you can get! Please inspect your fuse holder and feed wire to the rear glow plug carefully.
This kit includes: