MSD Dead - Help with direction please

[ToddMcF2002]

So the 6AL died in my 1969 GTX. I did not install it - but I have no desire to replace it. My car has a 72+ harness, dual resistor, 70+ voltage regulator and alternator. Seems like the cleanest path to delete MSD is to go with the 5 pin? I'm open to trashing the whole engine harness but I really don't want to toss my new Power Master alternator. Any thoughts?

 

[ToddMcF2002]

Another thought - I really HATE not having a wiring diagram to follow and given the MSD install I'm sure there are cut wires to worry about. What year engine compartment wiring diagram should I be working with?

 

[snakeoil24]

Msd is far superior to 5 pin chrysler

 

[ToddMcF2002]

Msd is far superior to 5 pin chrysler

I have lots of cars and butchered harnesses and dead MSD's are difficult to support. It appears my car is running a 1973 harness because it matches the diagram at least for Dodge. Can't find a 1973 Plymouth diagram anywhere.

 

[Don Frelier]

There are several other options.
The Chrysler style is available but they have quality problems as well.
Pertronix, Mallory and summit offer lower cost multiple spark discharge units as an alternative.
You should verify that you are getting a signal from the distributor before replacing the unit.

 

[ToddMcF2002]

There are several other options.
The Chrysler style is available but they have quality problems as well.
Pertronix, Mallory and summit offer lower cost multiple spark discharge units as an alternative.
You should verify that you are getting a signal from the distributor before replacing the unit.

I just checked the MSD distributor magnetic pickup - resistance is bouncing as I crank so I think that is at least good. Jumping the pickup on the MSD box itself did nothing. What direction would you suggest?

 

[Don Frelier]

Probably the easiest cleanest solution would be the Chrysler style ignition. Carry a spare box and ballast resistor in the car. Note that you'll need to modify the pickup wiring and it is polarity sensitive.

 

[ToddMcF2002]

It appears the 4 pin unit will work in place of the 5 pin. Can I also change to a 2 post resistor? It doesn't seem to affect the alternator wiring at all?

 

[66Satellite47]

How is your 6AL wired into you 5 pin plug? Really good ground is the key, MSD or Mopar ECU.

 

[Gus chiggins]

It appears the 4 pin unit will work in place of the 5 pin. Can I also change to a 2 post resistor? It doesn't seem to affect the alternator wiring

So the 6AL died in my 1969 GTX. I did not install it - but I have no desire to replace it. My car has a 72+ harness, dual resistor, 70+ voltage regulator and alternator. Seems like the cleanest path to delete MSD is to go with the 5 pin? I'm open to trashing the whole engine harness but I really don't want to toss my new Power Master alternator. Any thoughts?

View attachment 1273880 View attachment 1273881

Check out moparconnectionmagazine.com they have an article on mopar electronic ignition. You can use your 4 pin ballast resistor for a 4 pin ecu.

 

[Mike67]

You can send the 6al to MSD and depending what they find will provably be around $100-150

 

[RJRENTON]

There are several other options.
The Chrysler style is available but they have quality problems as well.
Pertronix, Mallory and summit offer lower cost multiple spark discharge units as an alternative.
You should verify that you are getting a signal from the distributor before replacing the unit.

IMO....I believe that the Pertronix system and maybe the Mallory system, are not capable of multiple spark discharges as there are not enough componentry present to do this. I speculate, as I've not seen the schematic diagram representing system's internal components....not the installation wiring but the internals of the module. The Pertronix system uses a Hall Effect switching transistor and a magnetic pick up coil all in one device to make-break the coils primary current creating the spark. There is not enough physical space to allow for a capacitor to create multiple spark discharges. The pick up coil assembly in the distributor is a simple pulse generator, that furnishes the switching module the off (breaks coil current and produces the spark) - on (turns on coil primary current or recharges the coil for the next cylinder) information to create the spark. That's the basic mechanism of how....the difference is the hardware used by the different manufacturers to make this happen.
BOB RENTON

 

[RJRENTON]

Msd is far superior to 5 pin chrysler

Really...? Based on what...cost, operational advantage, ease of installation, longevity. Its like comparing apples and oranges as they (the different systems) both create a spark....just differently....
BOB RENTON

 

[Gus chiggins]

Really...? Based on what...cost, operational advantage, ease of installation, longevity. Its like comparing apples and oranges as they (the different systems) both create a spark....just differently....
BOB RENTON

I'm no expert, but ma mopar seems ok to me. Aftermarket stuff seems to be more trouble than it's worth. It all depends what you like. Of course i would not tell anybody what to do with their car.

 

[Don Frelier]

Really...? Based on what...cost, operational advantage, ease of installation, longevity. Its like comparing apples and oranges as they (the different systems) both create a spark....just differently....
BOB RENTON

I have the MSD streetfire on my Charger having switched from the Mopar "Orange box" which I ran for probably 12 years or more.
I can tell you first hand it started easier, idled better and it started pinging.
Had to back off the timing a bit.
So yes my first hand experience was that MSD works better.

 

[snakeoil24]

Really...? Based on what...cost, operational advantage, ease of installation, longevity. Its like comparing apples and oranges as they (the different systems) both create a spark....just differently....
BOB RENTON

1. Spark quality.
2. Durability.
3. Timing stability.

 

[ToddMcF2002]

I undid all the MSD wiring and found the intact HEI harness buried and mostly uncut. Looks like the car has been running the MB2510 harness with MSD on top of it. So for 30 bucks I can clean it all up. I ordered the 4 pin unit and a new 2 pin ballast resistor. MSD is going in the hopper.

 

[RemCharger]

Really...? Based on what...cost, operational advantage, ease of installation, longevity. Its like comparing apples and oranges as they (the different systems) both create a spark....just differently....
BOB RENTON

I'm with Bob on this one. Ran an orange box into the 10s on juice. Saw waaaay too many rpms (8200), didn't miss a beat.
Put an msd on, didn't change a f#cking thing.

 

[RJRENTON]

1. Spark quality.
2. Durability.
3. Timing stability.

That's swell, but you need to quantify your numbers.....like:
1. Sark quality: Orange Box = 10 MSD Box = 10.5 volts or 2000 or 40,000 volts...appearance is too subjective.
2. Durability: Orange Box = 10 hours MSD Box = 10.5 hours or 2000 hours or 10 years
3. Timing stability: Orange Box = 2.5° degrees @1500 RPM MSD Box = 1° Degrees @ 6000RPM or 0° degrees @ Valve float RPM. All measurements taken from the same begining point or initial RPM.
In order to accurately compared both boxes, they must be measured using a common criteria at identical measuring parameters, ideally on the same engine (dyno runs or 1/4 mile ETs or similar). Just talking out loud.
BOB RENTON

 

[MCODECUDA]

Going from the Chrysler Electronic to a MSD is like going from points ignition to Electronic Ignition. I’ve had them in two cars now without any issues.