72 Diagram and now MSD question

Anyone have a 72 Dodge or Plymouth service manual that covers Dart/Duster/Demons? I need to know where the dark blue wire that attaches to the voltage regulator goes. Which pinout on which bulkhead connector, and where this attaches to the fusebox (I think that is where it goes)
Any help would be appreciated.

Oh yeah, if it matters this is on a V8 Duster.

thanks in advance

Things keep getting stranger. I've redone most all the wiring under the hood associated with the MSD-6A that a P.O. installed. After downloading the 26 page instructions for it I discovered the main power feed was hooked directly to the alternator.....which the instructions said DO NOT do.

I also ran new lines to the ammeter and thought I had all this straightened out. Unfortunately the ammeter flips wildly from 0 to almost pegged to the positive as the car is running above idle. I had already replaced the alternator last weekend cause it had crapped out, so I decided to replace the regulator today. However, as you might have guessed that didn't fix the wild swings.

SO...anyone who is running an MSD-6A (or similar) and have an ammeter hooked up also, please let me know what, if any, issues you've had, and if you have any suggestions about this issue.

No one?

No guesses?

Hi 69, i am using the MSD6al box with out any problem. however i ran the power direct from the big stud on the starter relay. It just fit my box location( original battery spot) better. I am using the constant current regulator from Mopar performance and i watch the system with an autometer volt meter. The original amp meter is still in the circuit and that does bother me. It works but i really need to get it out of there. All my new wiring was done (stand alone) using 10 or 12 ga THHN wire, like for the 6al box, retard box, elec fans, nitrous system etc. its probally overkill but it seem to work fine. All the factory under hood wiring was replaced also. I also have redundent grounds and relays were needed. I would try your current setup with the amp meter bypassed to see how it works, it should be fine. Hope this will help.

my 6 al box had a dirt simple wiring diagram on the bottom of the box. the actual spark box.

Hey 69, the schematic on page 19 of the msd .pdf shows the correct chrysler hook up. it sound s like you have to rewire someones mistakes. It is pretty stright forward.

Hi 69, this link has a robust soultion to the old anmeter problem. they talk about upgrading the whole system.
http://www.allpar.com/history/mopar/electrical.html
It is from Mopar action from 1999, very detailed with pictures. This would be a good one to post for all the members.

Thanks for the responses. This thing was a real mess when I started, but it ran pretty well. All the problems started when I broke out the pressure washer and cleaned the bay before a show. (the pic below will give you all an idea what I started with)

Anyway, it isn't hooked up like on page 19, because this was a /6 point ignition car, and was never converted to electronic using the MP stuff. It IS running a Mopar electronic distributor and is wired like on the top of page 23 for a Mallory distributor. And except for wiring 2 times to long and the main power for the MSD being hooked to the alternator that's the way it's wired now.

I have rerouted the main power to the battery, which is also where one side of the aftermarket ammeter goes. The other side of the ammeter goes directly to the alternator. I also made sure I did one wire at a time to insure they stayed hooked up the way they were.

So the "magnetic pickup" is connected to the distributor
tach output to the tach
"heavy red" to the battery
"heavy black" to the block (now there is also a ground strap on the block)
small red to ignition switched 12v
orange and black to coil.

In the "after" pics below you can see I replaced the alternator cause it seemed to have died, cleaned up all the wiring, got rid of all the cracked insulation, and the yellow wire that can be seen at the alternator is the feed to the aftermarket ammeter.

SO...more thoughts?

(oh yeah....I also ditched the electric fuel pump, tiny radiator and fan, and all associated wiring. this was all done before the ignition rewire)

Hey 69, you should be in good shape. The problem is gone i presume? The only question i have is in your 2nd picture the alternator Case looks like it positioned titled with the front down, or is that an illusion. I love them A-bodys, i had a white 73 340 duster that was a convertriple, remember those? Fold down rear seat, sun roof. That was a great street machine.

It's an optical illusion. It's level on the car, but was a bit of a pain cause things were set up for that chrome alternator that was in that first pic.

The problems still exist. It has a miss over 3000rpm, but not below that. The ammeter is still flopping around wildly. I called MSD today and explained the situation. They said "You moved the main power AND ground? It didn't like that. Run the ground to the battery."

The ground had been bolted to the back of the passenger's head.....like 4" from where it is now. There was NO ground strap from the motor to the firewall, but there is now. That groundstrap is bolted to the head where the MSD ground had been, and is bolted down to the bottom heater fan bolt, along with the MSD ground.

It should be perfect.....but it isn't. So tomorrow I'm gonna whip up a ground to the battery, but my guess is it won't change anything.

Btw, I remember the convertriples. I graduated high school in 73, and remember sitting in a Petty Blue one at the State Fair.

sweet

Found this on the MSD problem web site.
This actually sounds like it may be a ground issue, even though it runs fine at lower rpm. With this unit, total timing is in around 3000rpm (about 18° advance) so it is not the timing curve causing problems.

If this engine has an aluminum intake it would be a good idea to supply a better ground to the black wire that connects the module to the coil cover. To do this, splice into this black wire and connect it to engine ground, this should improve the high end miss.

Ready for the latest?

Today I made a ground jumper so the MSD is now grounded directly to the battery. No change. So I called MSD again. I told the guy on the phone what was going on, and that I had run the ground to the battery.

He tells me.....

That the power to the MSD (despite the fact it wasn't to begin with) has to be connected to the pos. post of the battery. He says the battery will act as a capacitor and will isolate the MSD from the ammeter, even if the ammeter is also hooked directly to the battery.

Add to that, he says the distributor leads cannot be run in parallel with any other wires carrying 12 volts (this despite the fact it had been like that all along). I brought up that fact, and he says I "changed the frequency of the electrical system when I rerouted the wiring."

This all kills me because
1) the main power was originally attached directly to the alternator (instead of the battery)
2) the main ground was attached to the head (instead of the battery)
3) the distributor leads ran along 12v (probably) 3 times farther than they do now
4) nothing, and I mean nothing works unless the aftermarket ammeter is hooked up

And that #4 makes me wonder if the main FACTORY lead from the alternator is doing anything at all. I have done nothing to the wiring associated with that, so I'm thinking there is a problem with that feed through the system.

I think I need a stiff:soda1:

Update....

Today I did what they suggested and ran the main power and ground all the way to the battery. I also moved the distributor leads away from anything with 12 volts on it. So I bust it off and guess what. You got it, still has the high speed miss. So I call their tech support........again.......and go thorugh the whole story including the latest mods.

Guy starts telling me things like the plug gap is wrong, the valve lash is off except I remind him it ran fine for MONTHS with the same plugs and it has a hydraulic cam (hence no valve lash)

This guy also tells me to change the plugs. I said well if I had some in my back pocket. So he says "well AutoZone has plenty in their pocket". I said great, except I live in the country and the parts store is miles away. Guy was really pretty rude all the way around.

Bottom line is the only thing they can suggest at this point is to send it in for repair. They said it could cost as much as about $85 to fix it (depending) which is close to 1/2 the cost of a new unit.

yipee:black_eye:

hey Runner, do you have a different distributor you can try with you current setup? Its just not adding up for me. If all the AL2 leads are routed properly, i would try to switch it out. I had a bad module in a chrysler electronic dist. that gave me similar problem over 3500 rpm. Even one of your mopar friends might have one you could try for few hours. It may be something is off with your current dist.

just for giggles disconnect the tach output wire. to eliminate tach short or something loose

Just as a question, do you have the green (-) from the msd6al hook to the black on the dist. and the violet (+) hooked to the orange on the chrysler dist? I know you said you have it connected but is it in the correct orientation. Not trying to be a dick, just double check it. Orange from msd to (+) on coil Black from msd to (-) on coil,And the white wire is not used.

Yep. I read the 26 page instructions before I dove in to this. The coil wires are correct, white wire not used, and (unfortunately) the distributor lead has a connector on it that is different than the one that comes on the distributor. So in order to do a swap, I would have to change the connectors at the distributor in the car back to factory connectors in order to try a different distributor.

ya, i forgot about the connector difference. you might be able to make up a quick jumper with a chrysler plug on one end and the msd on the other. i will tell ya, sometimes the simple stuff is a PITA.

Tem:

I just e-mailed you the A & B schematics for a '72 Duster. Can't hurt at this point...

Keep us posted.

Bambi says hello. She had a Great Birthday Party!!!
:grin:

ACME

Thanks Ray. I've already sent him an email with an update and (for the rest who are following along) after a quick look at the diagrams I can't believe this thing has been running as well as it had been. FUBAR is definitely the word.

So I'm going to be replacing the engine and dash harness in it to eliminate all the gremlins. Otherwise I'll be working on this till I'm to old to drive and enjoy it.

Thanks all, and anyone have a really nice uncut dash harness for a 72 Duster?