Transistor Module swap *PLS HELP*

[Zed Head]

6 minutes ago, Halo8u said:

 Also, the dizzy is reading 720ohms.... that doesn't sound right compared to 250 .... dizzy could be done for
 

720 is right. I edited my post.

[Zed Head]

6 minutes ago, Halo8u said:

I'm getting full 12v from the coil to the dizzy cap. So the coil is fine, so my issue is now leading me to a distributor issue, maybe.
 

If you really are getting 12 volts to the center electrode of the cap that would be a sign of a bad coil.  Shorted internally.  Might be your problem, it would probably get worse as the short caused heat.  The distributor cap only sees voltage when spark happens.  It will never see battery voltage.

You might have found it.

[Halo8u]

Could be, I put my multimeter in the wire coming out of the coil that goes into the dizzy and have constant 12v from that

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[Zed Head]

The common test for a short is to measure resistance from one of the terminals, + or -,  to the center terminal.  It should be in the thousands of ohms of resistance.  Like 10,000 ohms.

[Halo8u]

So, primary resistance should be around 0.7 ohms, I'm getting .2

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[Halo8u]

The test you told me to do got me around 5.4k ohms. Spec says it should be 4.5k

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[Zed Head]

I realized after I posted that the center post does see voltage.  Just across very high resistance.  So the 12 volts wasn't wrong, but it was the wrong test.

Your numbers don't look terrible but they might be a sign of a problem that gets worse with heat.  They're not quite right.  Where did you get your specs?  0.2 ohms is very low, even for a GM HEI module.  Spec. is 0.6.  That would create extra heat.

The HEI module does put more work on the coil.  If you have a spare coil it would be worth a swap.  It's not uncommon for coils to fail when they get hot, then work when they cool off.  Ignition modules do the same.

Edited August 16, 2018 by Zed Head

[Halo8u]

Got my specs from MSD's website. Blaster 2 coil is .7ohm primary and 4.5k secondary. I dont even know what primary and secondary means in this application honestly.

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[Zed Head]

Primary is resistance to voltage passing through the coil and module.  0.2 is low and will cause the module and coil both to get hot.  Heat can cause problems.  If you're sure of that 0.2 number I'd get a new coil.  I would not run that with my parts, and I run some weird stuff some times.

You might even be able to feel the heat buildup by touch while the engine is running.  Put a finger on the module and see if it hurts.

Edited August 16, 2018 by Zed Head

[Halo8u]

Gotcha. And my module is kinda funky looking, discolored in the middle, I would guess heat. But, I need a better heatsink and mounting surface anyways. I'm going to get a new coil and ign module with a heatsink. This setup has seen hell from trying to revive the car. With crappy wiring too. Now that I have new wires, itd be good to start with all fresh parts. I'll order the parts tomorrow and update you when they've arrived and I install them.

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[Halo8u]

Also my test was from + to - on the coil which I got .2ohms, second test was from + or - (I tried both) to the center. Which I got 5.4kohms. Just to clarify how i reached those numbers.

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[Zed Head]

Your test procedure is correct.  Discolored module is a sign of overheating.  I think that the manufacturers actually include that in their instructions.  Since it runs now, and ran well before, I'm guessing you'll see good results with new parts.