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Discussion Topic:
6-Volt: Changing It Back To Positive Ground....
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mdurhan |
08-30-2011 @ 1:01 PM
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Posts: 64
Joined: Mar 2011
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Howdy, boys: I wish to return my 6-volt system back to positive ground (from 6-volt negative ground) in my '39 Deluxe. I presume I would need to: 1) switch the battery cables at battery terminals 2) re-polorize the generator 3) swap the leads to the ampmeter gauge 4) Swap the coil leads?? And, perhaps, the voltage regulator and starter will be okay?? Thank you in advance for your courtesies in response to these questions. I remain Much obliged, Mike Durhan
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ford38v8 |
08-30-2011 @ 5:36 PM
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Mike, I think all you need to switch is the battery leads and the ammeter direction through the loop, and polarize the generator. Nothing else should be affected. Edit: Mike, this post should have been part of your previous post on the same subject. Makes for easier reference if dealing with one subject. Since I hadn't seen the other post till now, and likewise Supereal's response, I'll address the coil issue a bit further: I'm not an electrician, but the way I understand it is that the coil primary and secondary are two separate circuits, not to be switched because you'd get much less secondary voltage as a result. The primary being fed by insulated wire and the case being grounded, it doesn't care a whit about pos/neg as long as everything else is equal. Alan
This message was edited by ford38v8 on 8-30-11 @ 5:55 PM
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Stroker |
08-30-2011 @ 6:32 PM
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Alan: I certainly agree with you regarding the secondary, as there is no physical connection between primary and secondary. I have always thought though, that it is better to have the primary-side points properly polarized, since over time, they transfer material from one point contact to the other. The "classic" thinking was that it was easier to remove the build up from the stationary point, than the movable one. Having said that; I can't imagine anyone with a 32-40 distributor filing points.
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ford38v8 |
08-30-2011 @ 6:59 PM
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Dan, I believe that the condenser would dump it's charge at the point when the battery is connected, and the first cranking with ignition on would load the condenser with the polarized charge. The points just play follow the leader. Am I wrong?
Alan
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Stroker |
08-30-2011 @ 7:11 PM
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Alan: I suspect you are right, but perhaps Super or Dolman have a take on this as well. Given that 32-40 points have an "opening" set and a "closing" set, any material transfer would only occur on the "opening" set. I really have a tough time visualizing electrons, as while I can design complex mechanical linkage, them electrons are spooky.
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supereal |
08-30-2011 @ 7:58 PM
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The primary and secondary windings are, in fact, connected. The upper end of the secondary (high voltage) is attached to the primary thirty and a half turns from the top. That is one reason it is difficult to diagnose whether the windings are shorted one to the other. The terminal to the connected side of the windings goes to the negative side of the system in a stock (positive ground) system, making polarity selection important.
This message was edited by supereal on 8-30-11 @ 8:01 PM
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ford38v8 |
08-30-2011 @ 8:44 PM
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Bob, I'm not understanding you. Can you please 'splain it again? I'll listen harder.
Alan
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MG |
08-30-2011 @ 11:29 PM
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Click on this link for a good/simple explanation and a diagram of primary and secondary windings common connection to one another. http://mgaguru.com/mgtech/ignition/ig104.htm
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51f1 |
08-31-2011 @ 8:05 AM
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The polarity of the high tension coil terminal is important. Reversing coil polarity will affect this. Some coils have a terminal marked "Distributor" or "Dist." Some have a positive or negative designation. On those, connect the positive terminal to the distributor (this pertains to positive ground systems only). The build up on the ignition points is affected by the condenser. An under capacity condenser will cause build-up on the positive contact and an over capacity condenser will cause build-up on the negative contact. Richard
This message was edited by 51f1 on 8-31-11 @ 8:11 AM
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supereal |
08-31-2011 @ 8:56 AM
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Alan: The primary and secondary windings in the coil ar joined together close to the low voltage input. Then, one end of the primary winding goes to the distributor, where the points furnish a ground, while the secondary (high voltage) winding terminates in the distributor where the rotor sends the spark voltage to the plugs. The coil is known as a "Tesla" type, named for the inventor. If a diagram would help, I'll post one.
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