Having trouble getting fire out of my mag, any experts here?

So far I've double checked the switch wiring, checked the cap/wires and that was all OK.

When I took the cap off and check to see what is grounded, I found that the ground stud is shorting to the body.

SO I pulled it out, and checked the strap that goes to the points, it's also grounded to the body (though it's not touching anything) poking around under the cap with the DVM it seems like there is a short somewhere, as most everything is grounded to the body, which is grounded to the block. It doesn't matter if the points are open or closed, it still doesn't go open to the block, so I'm assuming that this is why I get no spark, since the generator is dumping all the charge to the block and not building up charge.

Anything obvious that I should look for that I may have missed?

Gavin,

Change points & condensor. If still no fire have Mike drop it off at Dowkers. The coils also go bad.

The, Governor / Dan Logan

You checked the switch wiring, but did you turn it on?

yes I did. 'On' is open on the switch.

The switch grounds to the block, basically shorting the ingition and making the path of least resistance change from the plugs/wires to the block, and discharging the mag output. So that's the problem that I have, is that even when you disconnect the switch from the lug on the outside of the mag, it is still grounded. The strap from the grounding lug to the points on the inside of the mag is grounded at all times, and I don't know why. The lug by iteself is isolated properly from the body of the mag, so the short is somewhere inside the body, I'm not totally sure how everything else in there works (condenser/generator/etc) so I'm a little confused from there. I just know that the switch is basically a redundant ground breaker.

Gavin,, if you want I can send you some phone #'s for Hewitt,Ferkel,and Stewart.. I'm sure one of them may be able to help you,, Just let me know.
The Wizard

First post wass kiddin...but..

got .016 on the points? You pushin that thing down the road already?

Does it have external coil or built in? Same theory but different testing style needed.On one current is gone thru coil to the lug and on the other one current thru lug goes thru the coil to switch,ground or whatever you call it but it is a ground.

That lug has to be grounded to complete the primary circuit which will energize the coil and build a magnetic field and it will collapse when the points are opened inducing a high voltage spark thru the secondary circuit in the appropriate voltage range according to the ratio of turns in the primary and secondary. A simple test is to spin it over by hand while holding the lug,you should feel a voltage the lug, turn slowly or sit down and sit mag down in something to save from breaking it. I believe they have make and break style points so they have to work together or not at all. The 2 dwell readings together will be @30 degrees. Old style dual points for us old guys are what they use. I have had one for years but we cannot run weed wacker ignitions in race mods.

If you feel no primary voltage,trace the lead back to the points,disconnect and measure primary coil resistance. If it is open or shorted it will be infinite or zero but should have a definite ohms reading on your dvom that is repeatable. Like 10,000 ohms will indicate a good circuit. The secondary coil can and should be measured also.
Make sure the points connection is centered or it may short at the wire to points hookup point. This is a common points replacement mistake.
The generator output flows thru the points and stops when the circuit is opened by the points causing a magnetic field surrounding the primary circuit to collapse on the secondary coil inducing the step up coil to out out a high voltage spark. An ignition coil is a step up transformer. If the primary is shorted there will be no secondary output. If you don't feel a primary voltage don't worry about secondary yet. Do diagnostics in orger.
Simple huh? go HOW STUFF WORKS.com type in magneto. They were perfected in WW2 for aircraft I believe and haven't changed much till this new solid state vertex came out.
I guess noone has ever tuned up a 60's vette or z with the hi perf dual points.Remember that grounding that lug will make it go, removing that ground will make it stop. It is not a light switch, a properly wired one that is. It is a ground side control and you are screwing with it like it is a power side control like a light switch. A ground side controlled light switch will shock you when it is off. Right?

Dick, thanks.

Do you have a distributor test bench at your shop? Dowkers cant get to it for a few weeks.

The points looked good and were centered, I'll keep an eye for that when I put them back in. They are cycling, I put it in with the cigarette wrapper trick, and checked with a buzz box.

I checked the coil like you said, red wire that comes out of the main body (and goes into the socket in the cap) to the black and yellow wires (primary/secondary, or is the condenser the secondary?) that come up with it. Always got 6.46kOhms.

Didn't check for primary voltage, its still in the engine, and I can't turn it over that fast, especially by myself.

When I talked to Vertex they said it was wired correctly, I had no fire with the switch on or off though, cause that was my first thought. I see what you're saying with the coils and the points though. That makes more sense to me now. I wish they would have told me how to check the coil though, they musta wanted their $95 to inspect it.

Gonna throw a new condenser in, and see what that does for me, it was cheap and it'll be here today. If that doesnt work I'll have to come up with something by next Saturday for our first practice.

We ran a dual point hi-perf setup in my nhra ss/g .... talk about a love/hate relationship ... (ok, wrong thread - I'm out)