Starter Damage Pic, Cranking Longer Than 30 Seconds

[74M35A2]

Thought I would post a photo of what happens if you hold your starter on longer than the specified 30 seconds. Brushes and armature/commutator run the hottest. Starter is a very powerful motor (6kW or so), with zero cooling. In the picture below this armature got so hot the varnish melted off the copper wiring, and that caused it to short out, draw more current, and then melted the armature wiring until it disconnected and stopped working. One low hour armature for reference. Don't use your starter to prime your fuel system. If your truck does not start in 30 seconds, stop, and figure out why.

 

[Nomadic]

Nice example of what not to do

 

[74M35A2]

Yep. This was not my starter, a portion of our facility acts as a warranty return center for our product(s). I needed a few different orientated nose cones, so I tripped upon this one during disassembly, and thought to post a lesson learned.

 

[Mos68x]

I never hold mine longer than 10secs, this beast or any other vehicle. My dad taught me that a long time ago and just haven't forgotten it.