[n20ta2]

I have a 7al2 ignition box and a hvc3 coil with a pro billet distributer that Im using the adapt a cap ford style msd cap on. Trying to fire my 461 for the first time and I get no spark at the plugs. I tried the trick of grounding the trigger lead with the ignition on and the coil wire pulled and set 1/2 inch from ground and I get spark when I pull the jumper wire. Msd says that means ignition is working properly, Is that telling me my coil and box are good? I put an ohm meter on the coil and the primary side gets .5 with meter set at 200 while the secondary side gets no reading with the meter set at 20k. Checked all my wiring, my trigger wire is good, coil wires are good and my leads to battery are good. Coil is grounded properly. I chexked the magnetic pickup in the distributer and that seems good too unless I did that wrong. Im stumped! Any help is much appreciated, really want this thing running

[TinInjun]

Where are you getting the 12 volt signal to turn on the box?

[n20ta2]

Accessory wire in my painless wiring harness. I just double checked it and its 12 v keyed and drops to 0v cranking. Thats probably my issue. I will try hooking the signal wire to the bat and see if I get spark tommorow. If that works I will need a new source.

[TinInjun]

That is your issue. The only hot wire while cranking is the original coil wire.

[n20ta2]

Originally Posted by TinInjun

That is your issue. The only hot wire while cranking is the original coil wire.

Ok jumped the box with 12v batt power and it fired right off. The pink wire I had been using for the trigger was the coil wire on closer inspection. So Im guessing bad ignition switch? Anything else cause the power to die when cranking? Thanks for your help!

[25stevem]

If this car we are talking about with this issue is the 69,then yes it could the ing switch on the lower top of the column, but it could also be that the switch is simply not adjusted right.

They have about 1/8” of adjustment play back& forth length wise on the column and that effect’s the interplay of rod coming down from the key tumbler.

[Bill Hanlon]

Which coil wire? Original stock fed 12v to coil when cranking (if that is the one you were hooked to it should have started and then died when you let the key out of the start position. The resistance wire or wire from the ballast resistor has no power when cranking, but gets power when you release the key. Sounds like the second one was where you were hooked to.

[25stevem]

According to my 69 engine harness layout the pink wire is the only hot going to the coil .
It also shows the purple going to the starter relay which brings the full 12 volts when cranking to the fire wall connector.
Even though I know better this layout does not show how the coil would drop down to the required 9 volts once the motor starts.

[n20ta2]

So This is the 69 gto and I also should clarify this is a brand new painless wiring harness. I did away with the external regulated alternator and the pink wire that was supposed to go to the coil was rerouted inside and connected to the msd box. This is also the wire painless suggest using to fire the box. I did take the column completely apart so maybe its just out of adjustment?

[TinInjun]

The 69 has two wires under the dash from the ignition switch. In the start position the resistor wire is bypassed. When the switch is returned to the on position, the start coil power wire is disconnected.. There is only a single coil power wire (black with pink stripe) in the engine compartment. The MSD box power trigger pulls no load so that wire will have 12 volts available in both switch positions. The resistor wire under the dash is black with pink print. The non resistor start only wire is yellow. Both wires connect together at the firewall connector. Looking at the connector it should be the slot that is 3 down and 2 over from the left. This is looking from inside the car.

[TinInjun]

Also want to add I have fixed this same issue with a few other cars that wired the MSD trigger wire to the acc side of the fuse box. Not a big deal, and a real easy fix.

[n20ta2]

Originally Posted by TinInjun

The 69 has two wires under the dash from the ignition switch. In the start position the resistor wire is bypassed. When the switch is returned to the on position, the start coil power wire is disconnected.. There is only a single coil power wire (black with pink stripe) in the engine compartment. The MSD box power trigger pulls no load so that wire will have 12 volts available in both switch positions. The resistor wire under the dash is black with pink print. The non resistor start only wire is yellow. Both wires connect together at the firewall connector. Looking at the connector it should be the slot that is 3 down and 2 over from the left. This is looking from inside the car.

Ok so if I understand you correctly I think Im using the correct wire. It used to be the coil power wire that was in the engine compartment (painless used solid pink for it and labeled it coil power)I removed it from the exterior bulkhead and routed it under the dash where my msd box is mounted. So if this is correct I have a bad switch or its out of adjustment. I have a battery mounted in the trunk as well, the wire it came with is also a little light in my opinion

[25stevem]

I think your issue is the fact that you unhooked this wire from the passenger compartment side of the factory bulkhead connector.

The inside passenger compartment wire harness off the Ing switch is where the switch either sent a full 12 volts to coil during cranking, or once started and in the run position put the 12 volts thru the resistance wire to feed only 9 volts to the coil.

Sorry I can’t help more, but I only have a diagram of the wiring in the engine compartment, not the passenger.

[n20ta2]

Originally Posted by 25stevem

I think your issue is the fact that you unhooked this wire from the passenger compartment side of the factory bulkhead connector.

The inside passenger compartment wire harness off the Ing switch is where the switch either sent a full 12 volts to coil during cranking, or once started and in the run position put the 12 volts thru the resistance wire to feed only 9 volts to the coil.

Sorry I can’t help more, but I only have a diagram of the wiring in the engine compartment, not the passenger.

No problem, im by no means an expert on this and I appreciate any help I can get. Painless had a note in there manual on this wire if using an aftermarket ignition. Basically what I did because I mounted the box inside was remove the spade conector from the bulkhead snip off the connector and soldered the wire back on so it was now inside. It was only a single wire not a duel wire to the spade so it should do exactly as intended?

[n20ta2]

I will double check there note and make sure I have the correct one though.

[johnta1]

Is this a 1969 GTO?

The wire you cut is probably the high resistance wire that lowers the voltage to 9 volts or so.

Should splice into the wire on the inside where it is 12 volts.
Wire I think is black with pink stripe.
Could cut that wire at the firewall (on inside) and connect it to the box.
But just as easy to splice it into that wire. (and no loose ends remaining)

[n20ta2]

Could be, I will check that.

[TinInjun]

As your box is mounted inside the car you need to find two wires from the factory ignition switch. The yellow wire and the black with pink printing on it. These two need to be spliced together to a single wire to the MSD trigger wire. I do not know what colors Painless made them but they should say in the instructions. The yellow is on pin “D”, and the black with pink print is on pin “E” on the factory ignition switch 6 pin connector.

[TinInjun]

Better yet, forget everything I have written as this is the simplest way to resolve your issue. Pin “B” on the ignition switch is not used(6 pin connector). It has power during start and run. Make a new wire and just use that pin to the MSD box.

[n20ta2]

Originally Posted by TinInjun

Better yet, forget everything I have written as this is the simplest way to resolve your issue. Pin “B” on the ignition switch is not used(6 pin connector). It has power during start and run. Make a new wire and just use that pin to the MSD box.

I couldnt get anything out of pin B on the ignition so I used the yellow wire and the coil wire together to get 12 volts Constant, tried cranking it and the starter now is cranking full time. I think that switch is bad seeing as I have no power at B and the starter issue or my brand new power master mini starter is bad. Will post back up once the switch is installed.