ignition wiring help

[ksurfer2]

With the key in the "run" position, I am showing 10.2 volts to the coil (positive prove on + side of Coil, negative probe on same ground the distributor ground wire is attached to).

 

[bearman]

do you have a power probe or a volt meter to see if you have 12 volts at the blue wire

 

[texas69bee]

You need to have 12v. Before installing a relay, I’d run to Oreilys and pick up a MSD coil. No where in the instructions does it say it is required but I would use one for a better output... Edited

 

[ksurfer2]

With the jumper wired as pictured above, I am getting 10.2 volts to the coil. Should that be enough?

 

[texas69bee]

According to the addendum, NO

 

[beanhead]

With the jumper wired as pictured above, I am getting 10.2 volts to the coil. Should that be enough?

Mine shows 10v on the start wire also, with the car off and key in 'run', that's not the issue...if you want to verify that you can do what you mentioned earlier and run a jumper from the battery to coil +. Carefully...and just long enough to check as you will not have any fused protection in the circuit. But I think something else is wrong..unless you have a helper to turn the key, set your phone up so it can record video of your meter, measuring coil voltage while you crank the engine...(let's make sure you're also getting coil voltage during cranking..)

 

[beanhead]

According to the addendum, NO

Is that what the addendum says, something about adding a relay? I can't read it... if the system absolutely has to have a full 12 volts before the motor starts then that would be the way to do it...

 

[ksurfer2]

Mine shows 10v on the start wire also, with the car off and key in 'run', that's not the issue...if you want to verify that you can do what you mentioned earlier and run a jumper from the battery to coil +. Carefully...and just long enough to check as you will not have any fused protection in the circuit. But I think something else is wrong..unless you have a helper to turn the key, set your phone up so it can record video of your meter, measuring coil voltage while you crank the engine...(let's make sure you're also getting coil voltage during cranking..)

Thanks. I will try all that in the morning (before the in laws show up). I did manage to grab a new MSD coil from the parts store (thank God they stay open late!). Tune back in tomorrow morning for further updates. Right now....beer time!

 

[beanhead]

And, don't hate me for saying this but.... The coil wire to the distributor is connected properly right?

 

[texas69bee]

Is that what the addendum says, something about adding a relay? I can't read it... if the system absolutely has to have a full 12 volts before the motor starts then that would be the way to do it...

https://documents.holley.com/frm33565_ready_to_run_add.pdf

 

[ksurfer2]

And, don't hate me for saying this but.... The coil wire to the distributor is connected properly right?

The coil is wired to the distributor as pictured in the instructions above. Absolutely no hate for mentioning...All here have been very helpful.

 

[beanhead]

https://documents.holley.com/frm33565_ready_to_run_add.pdf

Thank you!

 

[texas69bee]

And if all is correct you may have a bad ignition module. This was the problem I had with mine right out of the box. Later verified by MSD techs.
Told them to keep it and went a different route.

 

[texas69bee]

Thank you!

Your welcome

 

[beanhead]

The coil is wired to the distributor as pictured in the instructions above. Absolutely no hate for mentioning...All here have been very helpful.

Yeah no worries...I was meaning the (secondary) big fat wire to the distributor cap though...(ugh so many of us have forgotten to reconnect it lol!)

 

[ksurfer2]

And if all is correct you may have a bad ignition module. This was the problem I had with mine right out of the box. Later verified by MSD techs.
Told them to keep it and went a different route.

I doubt that is the issue. The motor ran fine on the dyno just last week, and nothing was changed during the install (carbs, distributer, all stayed on the motor).

 

[ksurfer2]

Yeah no worries...I was meaning the big fat wire to the distributor cap though...(ugh so many of us have forgotten to reconnect it lol!)

I made a new one, and when it wasn't working, grabbed the old one that I new was working, no change.

 

[ksurfer2]

My saga continues....So I put the new MSD coil in and wired directly the battery, With my multi-meter, I was getting a full 12 volts when the probes were on the + terminal of the coil and the firewall. However, I was getting 0 volts with the multi-meter probes on the + and - terminals of the coil. I made another jumper and ran a ground wire from the - terminal of the coil to the firewall. No I have a full 12 volts between both terminals of the coil. Still no fire, and the coil got EXTREMELY hot very fast. Everything is now disconnected as I am completely stumped. Only thing I can think is maybe the coil was bad out of the box and I should hook my old coil back up again.

 

[BeepBeepRR]

You should start with the wires that went to the ballast resistor. With the key in the run position you should have voltage on the blue wire at the coil. If not then I would check fuses and or fusable links. You only mention the year of the engine. What car is this in?

 

[ksurfer2]

It runs!!!! Here is what was happening, the wire I was using to power the coil only had power in run, but no power in start. So I tracked down another wire with 12v in start, but none in run. Spliced those two together and now it starts and runs!

Thanks to everyone for your advice and assistance.