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TR4/4A Testing the starter

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Dash

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While I'm waiting for the chassis to come back from the Dermatologist ( my new term for having it blasted) and since everything is removed from the car I'm trying to test everything. 1st up is the starter since it hasn't had to crank anything in 20 years. When it all goes back together I want to change the electrical system to negative ground and not being an auto electric genius here's my question:
The starter is polarized obviously for positive ground at the moment so to test, I attach the positive from the battery to the starter body and the negative lead to the terminal? If I reverse the leads will that re-polarize it to negative ground?
If my logic serves me well, I'm pretty sure the wiper motor doesn't care...?..
As always thanks for any input
 
To test run a starter I usually set it against a curb in my garage and brace it with my foot as I touch a lead to it. One lead is already clamped, the other is just touched briefly.

The motor has a lot of torque so if you have not secured it in some fashion the case will want to spin as well as the armature. There will also be a spark at the moment the lead makes contact.

In my experience, such a test only reveals that the motor works - the real test comes when you see how it performs cranking the car.
 
Ah yes.been a while but some of this stuff is starting to make it's way back around in my brain..it's the generator that needs the polarity switched..I remember there's a way to bench test that and involves some creative wiring but I think I'll try to find a parts place that is set up to test generators..some places used to do that for free..hopefully I'll get lucky and find someone old enough that actually knows what a generator is..ha
btw the starter motor runs nice and smooth but as Geo says that's only half the test but at least it's a good sign so far.
thanks guys
 
I've had trouble for years with a Lucas Land Rover starter which would spin freely but did not have enough power to crank the engine enough to start it. I had a friend turn the commutator which actually didn't look to bad but the magic bullet was spending at least an hour with a hook shaped end of a hacksaw blade cleaning out the hard mica between the segments. Seems like cleaning out the mica allowed the brushes to make a good solid contact with the commutator rather than be held off by the mica insulators just enough to lower the power. Voila, like a brand new starter !!!

Doug
 
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