how can I Bench test a starter

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machattack

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Joined
Apr 27, 2019
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Location
Idaho
My Car
1971 mustang mach 1 351c 4v auto fmx
1968 mustang gt 302 4v 4 speed
Howdy from Idaho,

I thought this would be a easy test, I found out differently. I had my neighbor join in to help, he is a master electrician and we still cant figure this out. 

I used a 12 volt battery grounded it to the starter case then put the hot to the single terminal. She spins fast and free but will not throw the gear forward. I assume the external solenoid. I do have a spare solenoid here.    

I dont have the car here to install it and test. The car is at the body shop 2 towns away . 

What is the proper procedure to test this one terminal magnetic thrown starter  :huh:  Geeezzz 4 hours is enough.  Please help me stang GODS.

sorry, The engine is a 71 351c 2v auto

 
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Hi Machattack,

Sorry to hear your problems with your starter.  Swapping out the relay will not fix your problem.  The starter is bad and will need to be replaced.  You can try taking it apart and cleaning it and checking the solenoid point assembly (under the cover on the side of the starter) .  The problem could also be in the starter drive yoke area ( the parts the throws the gear forward.  See the exploded view.  This is a typical Ford starter. Hope this helps you.



 
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Take it to an auto parts store.  They have testers there.

kcmash

 
If nothing was wrong with it, everything would work the way you did it. Your bench test found a problem, the test failed, not your method.

 
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yes i totally agree with others... you did it right... the bendix could be dirty and not able to move or the solenoid is bad. take that sol apart and clean and recheck. see if u can remove the wire on the sol from the starter and just hit that with 12v and ground still on starter body.

 
Thanks Guys for all the info given. You are always very helpful.

So.......... frustrated and still not working I took it to a old time shop here in town that rebuilds starters from locomotives to ferrari starters.

One of the field wires was broken and it would not make the magnetic current needed to throw the bendix gear forward. They recommended I buy a oem rebuilt starter for $55.00 from them.

Interestingly they asked what horse power was the engine producing and how high was the compression? Said the oem starter was marginal to turn over a 500hp engine. They kept the original core and told me they would build a starter that could produce enough torque to turn over 1000 hp easily. So I could call and have that built but I figured I would wear out this one first :)

God speed ( hope god drives a mach 1)

 
Glad to hear you got your problem solved. That's one of those tuff type of problems that hard to find. There are a few good videos on you tube about checking the field, commutator and armature on a motor for shorts. Easy enough to do with ohm meter. It would be something you would not think of doing it since the starter ran.

 
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