PeachParts Mercedes-Benz Forum - View Single Post

JimSmith · #4 10-10-2002, 08:53 AM

Tinker,

Check the connections to the battery and the starter. The battery ground, and the cable connection from the line to the positive post from the starter can be getting corroded. Poor connections usually get much hotter than the cable itself as there is a significant voltage drop across the corrosion products. If the cable itself is getting very hot there is a chance the cable has suffered some damage from either heat or being crimped during some other repair effort.

Anyway, the idea that the starter is getting weaker as it runs longer sounds like you have a connection problem, cable problem or the starter insulation is bad. I have seen the starter issue on Diesels regularly. If it is the starter, buy on from FastLane as theirs are Bosch rebuilds and get the stator rewound if the insulation is weak. Most other starter rebuilds are confined to mainly mechanical items, like bearings, brushes, the solenoid or a paint job. Rewinding cost effectively requires special tools and machines typically only available at the OEM.

Old stuff, especially starters that have had some hours spent cranking cars reluctant to start will have problems with the winding insulation. This is because the starter output rating is based on being used "intermittently" meaning for 10 seconds or so a couple times a day with long cooling down periods between starting attempts. If you run the starter for a few minutes continuously you will overload it as its continuous rating is much less than the intermittent duty rating. It will heat it up significantly more in continuous duty, which is not a design condition. Thus, the insulation will break down, leading to lower output and internal leakage of current (shorting), and ultimately to the demise of the starter. Fixing bearings and solenoid won't address the winding problems.

Good luck! Hope this helps, Jim