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coil problems

1K views 32 replies 3 participants last post by  PetesPonies 
#1 ·
This is my first msd product. I own a 1966 mustang v8 4b. Previously for the coil I had a tractor coil and it worked but I figured I needed a new one so it would have more volts. I bought a msd blaster 2 and hooked it up. I hooked up up the battery and one of the distributer lines to the positive and the other distributer line to the negative. It will start while I turn the key but as soon as I stop turning the key it turns off. I have a pertronix system in the distributer. I don't have a resistor. Do I need one or what is going on. Please help. When I put on the old coil it still starts up fine and idles.
 
G
#2 ·
You don't have power to the coil and Pertronix when the key is in run. You have it only when you have the key to start. That power comes from the brown wire on the solenoid, but when you release the key, it goes away. You have messed up the hot wire to the coil.
 
#4 ·
Pete these are the three wires that were hooked up to the old ignition and they worked. I have the red from the distibuter and the red with black over it on the positive and I have the black from the distributer on the negative. Do you think I need a ballast resistor? The reason I say this is because my last coil was from a tractor so it wasn't as big and didn't push out as many Volts. Thanks
 
#7 ·
You should have 3 wires on the coil + and 1 wire on the coil-.

Coil+

1. RED/GRN from firewall (switched ignition "on").
2. RED (to Pertronix)
3. BROWN from Starter Solenoid "I" post.

Coil-
1. BLACK from distributor (Pertronix).
 
#11 ·
I'm a bit color-blind. What color is that wire? There should be 3 wires in the "gauge harness" that feeds the coil. One goes to the coil, the other 2 to the oil pressure sender and the water temp sender. My mistake on the 3 wires... the BROWN wire is most likely spliced near the firewall connector.

What is happening is that you have power being provided to the coil by the starter solenoid when the key is in the "Start" position, but no power when the key is in the "On" position. This can be caused by a number of factors from a bad ignition switch, to a disconnect under the dash between the RED/GRN and PINK wires to a burned up resistance wire, etc.
 
#13 ·
I'm sorry about this guy's but I'm new to this and I'm trying really hard to learn. All this elecric stuff is crazy to me compared to engine stuff. Are you sure I just dont need a resistor? I just don't see how it could work with the old coil and the same exact setup and now it won't work. And I did take pics before I put in the new one.
 
#14 ·
Because SOMETHING failed between then and now. Was replacing the coil the only thing you did? Did you accidentally turn the ignition "on" with the wire disconnected and grounded on metal? Like Forrest Gump says... "_ _ i t happens.".
 
G
#15 ·
The brown wire I spoke about earlier and the one Bart mentions, doesn't physically go to the coil. It is mixed into the the stock wire that leads to the coil, before the engine harness. Stock, only one wire coming from the ignition, goes to the positive side of the coil. The wire on the negative side goes to the distributor. With a Pertronix, you add another wire to the positive side of the coil and still one wire running from the negative side, to the distributor Pertronix unit.
 
#22 ·
Probably not. The original Mustang coil was technically a 6-volt unit that used an integral resistance wire under the dash to supply around 7 volts running and 12 volts starting.

Sooty, black plugs is more likely the result of an excessively rich fuel mixture or the wrong heat range spark plugs.
 
#27 ·
Ok so what if the pertronix wires arent making contact somehow? That's the only thing I can think of. I've been leaving a washer on the bottom then putting the wires then a nut. Should I maybe try without the washer. I'm being honest about the old one. I have it connected the same exact way. I just don't understand.
 
#32 ·
Ummmn, Ii don't know because I can't see under your dash....

Ideally, with a Pertronix Ignitor 1, what you want to do is the following:

1. Find the RED/GRN wire at your ignition switch and splice in a fresh 16ga wire (I like RED in color) to run out through the firewall to supply the RED wire on your Pertronix Ignitor with a full 12V of switched ignition power.

2. Use an ignition coil intended for use with an external resistor with .7 to 1.5 ohms primary resistance. The Blaster2 should fall within this range.
 
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