Starter issues

So we got our car back together after a lot of changes... hoping someone can help us troubleshoot our current starter issue.

We have a 70 Charger that we finally got back together after a year of tranny/suspension work(saving money for parts). We moved the battery to the trunk with 2/0 welding wire. We bought a new 180lb powermaster high torque mini starter. We had issues with the car turning over slowly and though the starter was the issue. We are running 11.3:1 compression.

The issue is when we turn the key over sometimes the starter just wines and the engine isn't turned over. The other times the engine turns over in an instant and it's up and running.

Here is a video of what it sounds like when it doesn't engage the motor.

http://www.youtube.com/watch?v=uBh12AJJHEA&feature=youtu.be

Obviously we should have asked for suggestions as it seems some people think powermaster is just overpriced junk... well this is the 2nd one we had to get from them so there could be some truth to that if this one is broke too. We are getting 10+v on the ignition wire while cranking and we are seeing almost all of the battery to the front of the car.

We also have an issue where the starter sounds like it is winding down when the engine is turned off. It shouldn't be on all the time obviously, but not sure what would cause that. Maybe a bad solenoid?

The attached picture is how we currently have the car wired.

What we are asking is if this is indeed a bad starter or might there be another cause that we overlooked?

Any insight would be greatly appreciated.

Thanks!

I may be wrong but it seems to me that the battery should first go to one large starter relay terminal and from the other big relay terminal to the starter.

I would try running the battery ground to the rear frame rail. Then add a ground wire of the same size frome the frame or k-frame to the block. May cut down on the resistance in the long ground ran all the way from front to rear. Sounds like you may have some other issues with the starter or maybe the relay.

So it's not in the picture, but we also have a chassis ground from the engine to the chassis in the front of the car. Like I said before we are using 2/0 gauge welding cable and the engine turns over great when the starter actually engages. In all honesty we are trying to get out of taking the exhaust, headers, sparkplugs back off to try to get to the starter again. Though it sounds like we should try the old starter and see if it does the same thing to eliminate the wiring or the starter being the problem. The old starter worked, it just cranked the engine over very slowly.

Appreciate all the feedback though. It's very helpful to hear from people with different perspectives.

Quote:

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The issue is when we turn the key over sometimes the starter just wines and the engine isn't turned over. The other times the engine turns over in an instant and it's up and running.

We also have an issue where the starter sounds like it is winding down when the engine is turned off. What we are asking is if this is indeed a bad starter

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Starter