Pertronix, up in smoke Options

[Doug Leggins]

Started working on the 72 again tonight. Thought that maybe I ruined the pertronix unit last night. After about a half hour I realized that I had a new Pertronix on the "new to me motor". Pulled the Pertronix unit and installed it in the 72.

Smoked the pertronix on the first attempt to start the car- AARRRGG!!! It really went up in smoke. Stunk something horrible!

Now I'm getting starting to get a little pissed! (IMG:style_emoticons/default/ar15.gif)

Time for a break (IMG:style_emoticons/default/beer3.gif)

[Bleyseng]

Aaaa, how did you hook it up??? (IMG:style_emoticons/default/smile.gif)

[Doug Leggins]

Well......wrong I guess.

It is amazing how quickly a good beer can have a calming affect. (IMG:style_emoticons/default/beerchug.gif)


But seriuosly - I hooked it up just like the one that i removed. I have a MSD 6AL unit and an 8910 tach adapter. I've double checked the wiring diagrams that I have and it all looks correct.

I fixed an ignition problem that I had but in the process I now do not get fire to the plugs. (IMG:style_emoticons/default/confused24.gif)

The starter cranks great now, just can't get the engine to start.

[Engman]

How did you wire it? I am no ignition expert but I bet somone here can tell you how to do it. In the meantime get a set of points in there until you get another unit. This will at least let you run the car.

M

[Doug Leggins]

I was in the process of getting ready to go back to points and not use the MSD just to get the engine to start. Then i realized that I was lucky enough to have an extra pertronix unit around. You know the rest - up in smoke.

I think that I'll give the points a try next.

I'll try to post the wiring set up in a few minutes. Got to get another beer to make sure taht the pissedoftedness does not come back!

[nebreitling]

better to keep a few brews on hand right in the garage just for things like this!

(i'd use points, and then switch to the crane optical)

[Doug Leggins]

The black and purple wire connects to the negative side of the coil -right?

[ChrisFoley]

Isn't the bk/pu wire for tachometer? That goes to coil + with the red Pertronix wire.

[Doug Leggins]

Isn't the bk/pu wire for tachometer? That goes to coil + with the red Pertronix wire.

Based on the diagrams that i have the blk/pu wire is for the tachometer but it goes to the negative side of the coil. The blk/red wire goes to the positive side of the coil.

Do I have this mixed up?

[Doug Leggins]

Here is my current wiring set up.

blk/pu wire from engine wiring harness to wht 8910 wire to wht MSD wire and to blk Pertronix wire

blk/red wire from engine wiring harness to red 8910 wire to red MSD wire and to red Pertronix wire

orange MSD wire to positive coil

blk MSD wire to negative coil

Also have a blk MSD wire direct to same body ground pole as the negative battery cable and a red MSD wire direct to the positive battery clamp

Anyone with an 8910 and MSD able to confirm? (IMG:style_emoticons/default/beerchug.gif)

[fiid]

You can check this by turning on your ignition (pertronix disconnected) and checking the voltage on both sides of the coil. One side should read solid 12v. The other goes negative when the pertonix or points make that happen.

[ChrisFoley]

Based on the diagrams that i have the blk/pu wire is for the tachometer but it goes to the negative side of the coil. The blk/red wire goes to the positive side of the coil.

You're right.
How would the tach get a signal if it had a constant 12v applied?

[JWest]

You can check this by turning on your ignition (pertronix disconnected) and checking the voltage on both sides of the coil.  One side should read solid 12v.  The other goes negative when the pertonix or points make that happen.

Can't do that with MSD (capacitive discharge ignition). You should not be testing anything at the coil with an MSD.

I think you need to run the purple and green MSD pickup harness rather than using the white trigger wire.

Purple (MSD) to Red (pertronix).
Green (MSD) to Black (pertronix).

If this is the case, you would need an 8920 tach adapter.

Just run points with the MSD for now. The points are just switching a transistor, so they have very little current running through them and will last a long time (and dwell is not an issue). An optical or magnetic pickup will improve spark timing consistency, though.