1984 300D Turbo Alternator
 

Hi all - this is my first trip here looking for advice. I am a fairly advanced DIY-er and working on my older MBs and keeping them in great shape is my hobby - they are all daily drivers. One is a 1984 300D Turbo with 300K miles that has had an on and off problem with the battery light flashing. My mechanic (whom I trust and value immensely) said the first thing I needed to do was to replace the cheap aftermarket alternator (put in by a previous owner) with an original Bosch unit. So I went to my favorite MB only recycle yard in St. Augustine, FL and got a used one. I put it in and the problem went away - for a while. I am convinced the problem really is with the wiring going to the alternator as moving the wires causes the battery light to flash. I am sure I can replace it, but I can't locate the exact wiring harness I need on-line at the usual places I buy parts. I have two questions: 1) does my diagnoses about the wiring sound right? and 2) can someone help me locate the wiring harness I need? Thanks. Bob in Melbourne, FL.

You shouldn't need to replace the harness. I assume that where you are moving the wire and getting a change is at the alternator. If that is the case, carefully unplug the connector from the rear of the alternator and pry the cover from the connector. This gives you access to the pins. You can simply crimp and solder the pins for a good repair of the connection.

Hope this helps,