Tell me if my MSD Blaster 2 coil voltage 70.3 volts (- pole) and 16 v (+pole)

[munger77]

Hi,
I've rewired the car front to back and just started it up. Changed Ballast resistor (read 2.4 ohms on ballast disconnected vs. the new one which correctly is 0.6 ohms).

Distributor is electronic OEM spec and I have a blue ignition module on the firewall and external voltage regulator box (EGN - FLD).

With the engine running, the (-) terminal on the coil reads 70.3 volts, and the (+) terminal was 16.4 volts. Idles fine. As it is running the Field/IGN on the voltage regulator are 15 volts. Battery is also freshly charged 100%.

Before I drive it, just want to make sure this sounds about right. Nothing is smoking or seemingly wrong, but I'm not an expert in this area. Let me know your thoughts and if there is anything else I should test using my power probe III. Thanks,

 

[snakeoil24]

Why do you have ballist with electronic msd will misread

 

[pnora]

Makes zero sense.

 

[Don Frelier]

Are you sure coil - wasn't 70.3 mV or millivolts?
The 16.4v number is way high.
Is it a mechanical voltage regulator?
What do you get across the battery terminals when the car is off?

 

[Car #4]

Makes zero sense.

I think he means “Why do you have ballast? With electronic MSD will misread.” People need to read what they’ve written before they post it and use punctuation so it make sense.

 

[pnora]

I think he means “Why do you have ballast? With electronic MSD will misread.” People need to read what they’ve written before they post it and use punctuation so it make sense.

The way I read it he only has a MSD coil.

 

[munger77]

I think he means “Why do you have ballast? With electronic MSD will misread.” People need to read what they’ve written before they post it and use punctuation so it make sense.

Thanks Pnora and everyone,
when I bought the car 7 years ago, it came this way - with a ballast resistor; external voltage regulator on the firewall (gray or black metal box IGN and field terminals on it); the blue ECU; and electronic distributor. The OEM wiring harness had melted several times in different places in the past, especially bulkhead and there were many damaged splices in the OEM wiring which made the car look good but not driveable! I have all new wiring on the car; and went with painless. I did not change ballast, external voltage regulator, ECU or distributor. The electrical wiring was hacked in many places and dangerous with older signs of burning and several wires were melted together near the bulkhead, so I took it out when I first thoroughly checked the car.

Now with the new wiring, circuits work fine; all lights; and circuits work as they should and it idles fine. The only thing strange is what I have mentioned.

Should I remove the ballast resistor from the circuit and should I remove anything else and then re-test? I will double check it isn't mV but I'm 99% sure it read 70.3 volts repeatedly when the car was idling.
LMK your ideas thank you.

 

[RJRENTON]

Hi,
I've rewired the car front to back and just started it up. Changed Ballast resistor (read 2.4 ohms on ballast disconnected vs. the new one which correctly is 0.6 ohms).

Distributor is electronic OEM spec and I have a blue ignition module on the firewall and external voltage regulator box (EGN - FLD).

With the engine running, the (-) terminal on the coil reads 70.3 volts, and the (+) terminal was 16.4 volts. Idles fine. As it is running the Field/IGN on the voltage regulator are 15 volts. Battery is also freshly charged 100%.

Before I drive it, just want to make sure this sounds about right. Nothing is smoking or seemingly wrong, but I'm not an expert in this area. Let me know your thoughts and if there is anything else I should test using my power probe III. Thanks,

In principle, MSD (Multiple Spark Discharge) system supplies the coil with a much higher primary voltage (vs the normal 12 volts to ground) to produce a higher secondary voltage based on the coil's primary/secondary volts/turn ratio. Did the instructions say to use specific ballast resistor (or not) and coil? Did you follow their (the MSD company) instructions or a buddy's suggestions? Just curious....
BOB RENTON

 

[Don Frelier]

In principle, MSD (Multiple Spark Discharge) system supplies the coil with a much higher primary voltage (vs the normal 12 volts to ground) to produce a higher secondary voltage based on the coil's primary/secondary volts/turn ratio. Did the instructions say to use specific ballast resistor (or not) and coil? Did you follow their (the MSD company) instructions or a buddy's suggestions? Just curious....
BOB RENTON

I'm fairly sure that the blue ECU he mentioned is a Mopar style and not an MSD. I'd that's the situation then your reply is completely unrelated and just confuses the issue.

You need to read more carefully Bob and stop making negative references regarding his friends.
It's bad form.

 

[RJRENTON]

I'm fairly sure that the blue ECU he mentioned is a Mopar style and not an MSD. I'd that's the situation then your reply is completely unrelated and just confuses the issue.

You need to read more carefully Bob and stop making negative references regarding his friends.
It's bad form.

WHY??? Most of the extra information provided by buddies is hearsay and usually incorrect.......a blue ecu means what? Why did the OP switch to an MSD COIL? My responses are more succent and are accurate based on the original question...perhaps I misinterpreted his question......is the OP looking for 50+ hp increase by changing the coil??? What is trying to be accomplished??? Is the OP using an RMS or peak reading volt meter? There is a difference. Unclear information results in incorrect information in return......just my opinion......but I'm not the "expert"......
BOB RENTON

 

[Don Frelier]

WHY??? Most of the extra information provided by buddies is hearsay and usually incorrect.......a blue ecu means what? Why did the OP switch to an MSD COIL? My responses are more succent and are accurate based on the original question...perhaps I misinterpreted his question......is the OP looking for 50+ hp increase by changing the coil??? What is trying to be accomplished??? Is the OP using an RMS or peak reading volt meter? There is a difference. Unclear information results in incorrect information in return......just my opinion......but I'm not the "expert"......
BOB RENTON

Again nothing constructive in this reply.

 

[Geoff 2]

So Bob, using your 'logic' in post #10 about ignoring a buddies advice......Does that mean if one of YOUR buddies asked for YOUR advice, they should ignore it.................

 

[Geoff 2]

Munger,
Is it possible you have a 16v battery?

 

[Don Frelier]

Thanks Pnora and everyone,
when I bought the car 7 years ago, it came this way - with a ballast resistor; external voltage regulator on the firewall (gray or black metal box IGN and field terminals on it); the blue ECU; and electronic distributor. The OEM wiring harness had melted several times in different places in the past, especially bulkhead and there were many damaged splices in the OEM wiring which made the car look good but not driveable! I have all new wiring on the car; and went with painless. I did not change ballast, external voltage regulator, ECU or distributor. The electrical wiring was hacked in many places and dangerous with older signs of burning and several wires were melted together near the bulkhead, so I took it out when I first thoroughly checked the car.

Now with the new wiring, circuits work fine; all lights; and circuits work as they should and it idles fine. The only thing strange is what I have mentioned.

Should I remove the ballast resistor from the circuit and should I remove anything else and then re-test? I will double check it isn't mV but I'm 99% sure it read 70.3 volts repeatedly when the car was idling.
LMK your ideas thank you.

Please post some pictures to help clarify the ECU type.
Battery voltage when car is not running?

 

[munger77]

Hi everyone, guess what? The meter was off!! I thought about it the next morning, and got my trusty fluke out and re-checked all voltages and they are consistently normal everywhere. So sorry for the for the confusion. And regarding the question about the ECU; it is definitely not an MSD or I would have said it was made by MSD. The ECU looks like the orange style basic mopar ECU, it just happens to not be orange. Maybe it is for a '72 or something but in any case, the car purrs beautifully and I'm glad that all my wiring is new, secure, done with painstaking detail, and good to go. Next time I'll double check readings with a second meter before assuming I did something incorrectly!

 

[RemCharger]

Hi everyone, guess what? The meter was off!! I thought about it the next morning, and got my trusty fluke out and re-checked all voltages and they are consistently normal everywhere. So sorry for the for the confusion. And regarding the question about the ECU; it is definitely not an MSD or I would have said it was made by MSD. The ECU looks like the orange style basic mopar ECU, it just happens to not be orange. Maybe it is for a '72 or something but in any case, the car purrs beautifully and I'm glad that all my wiring is new, secure, done with painstaking detail, and good to go. Next time I'll double check readings with a second meter before assuming I did something incorrectly!

The meter was my first thought when you posted the weird #s
The blue box was the over the counter Chrysler ign kit. Keep the resistor. It's protecting the box.

 

[Don Frelier]

Okay good news.
The meter reading was why I asked for battery voltage.

 

[RJRENTON]

So Bob, using your 'logic' in post #10 about ignoring a buddies advice......Does that mean if one of YOUR buddies asked for YOUR advice, they should ignore it.................

That depends on whether they or you believe me or hearsay from others.....and if these people understand how a coil ignition system operates outside of the ECU OR BALLAST RESISTOR, which simply switches coil's primarycurrent limited by the correct ballast resistor......im sure which understand the basics of how...but not the why...including coil types...as you noted previously but copied from some magazine article, which you seem to have taken as a gospel or definitive source......but...that's just my opinion........PM me if you want to discuss further.....
BOB RENTON