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Old 02-05-2006, 04:05 PM
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Doc here,

To measure the Coil Resistance on the Stock General Mystery Coil, Set your DVOM to R X 1 or autorange, and Calibrate the scale, (It should read 000 , or close to it, if not recal, change the battery or note the difference)

Place one probe on the "BATT" Terminal, The other On the "TACH". Observe the reading..It SHOULD read LESS than an Ohm, but MORE than 000. Outside of that range, replace the coil...

On the Secondary Side, Set your DVOM for R X 10k, or autorange, Place one probe on the "BATT" Terminal, the other on the Rotor button pickup carbon element..note the reading, then move the "BATT" probe over to the "TACH" terminal, In Both Cases, your reading should be between 6,000 and 30,000 ohms ..out side that range, the coil is bad..

If that checks out OK, I'd suspect the module..You can take that to Auto Zombie and have it tested for free..do it several times to get it hot..If it is bad, and you get a replacement, HAVE it TESTED too, before you leave the store! The fail rate out of the box is like 1 in 3 or 5...

If it is bad you'll spend weeks scratching your head saying.."No it's new..can't be bad.."

IN either Case, replacing the old module back in the Dizzy, or the New, DO not forget the heatsink compound, or you'll do it again very soon..you can get a tube for the old one at the Auto parts store while your there..The new one comes with a tube..

If the Module does check good, and it's a no spark issue, then the next component to fail would be the Magnetic pickup in side the dizzy, you can look up the Specs for your truck in ohms..(two are given If I remember for year boarders..before year xxx was xxx, after year xxx was xxx type thing)

Or a quick and dirty test is just put the star in between high lobes, and pass a mailable screw driver in front of the pick up, If the ohms reading jumps up then down, It's doing it's job. If not ..

You need to pull the Dizzy, remove the drive gear, and disassemble the dizzy to get the unit out..

That should get ya runnin' mon..

Doc
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