MSD 6A Install Help! *Update* Attempt #2

[4X4HIGH]

The distributor was in there since I installed the engine.



The small red wire is hooked to the distributor power wire
The small orange wire is hooked to the B+ terminal
The small black wire is hooked to the C- terminal
The ignition module was removed and the purple and green wire hooked to the magnetic pickup
The white wire is unused
The gray wire is hooked to the RPM input signal wire for the ECM
The big red wire is hooked to a terminal strip fed directly from the battery
The big black wire is hooked to the negative battery cable

I have confirmed battery power and coil power to the box. I even tried to re-install the filter for the ECM RPM signal which was required when not using an ignition box.

In the morning I am going to confirm that I have a good tach signal to the ECM, then I don't know what else to do.

What/where is this gray wire?

 

[JDNobodi]

Well, unless someone else has an idea, it sounds like you got a bad box.

Since there is not anything you can do about it today, if its not too much trouble, either try hooking the coil up to 12 volts directly and make and break the contact to be sure the coil is actually firing, or find some other style coil and try it with the box.

Like I say, that box puts a much higher voltage pulse out than normal, and there are some coils that cannot handle it.
But, if the red LED goes out, and it will not fire again until you pull power, it sure sounds like a bad box.

I know you hooked up the small red wire to a good power source, and I am assuming that you know your ground is good, but you mentioned that the white wire was not hooked up.
That is correct for your setup, but it can be used as an engine kill switch by hooking it to ground.
As long as its hooked to ground, the engine will not run.

Any chance it got pinched under the unit or something?

Also, there used to be someone here who was an vender for that company I think. Not a clue as to who it was, and not sure if there is a way to search for them.

Maybe someone else remembers who it was, and will let us know. If they are still active but not on much, you could send an E-mail.

Well, I agree with you. And you are thinking things more ahead.

I think Philly87 is the MSD tech rep.

 

[Chevy305]

Ya the box has to be bad. I can't think of any other possible problem. I googled 6A box install with HEI and found someone on another forum that had the same problems as me and his box was bad. Talk about poor quality control I'm not the only one getting a bad box out of the box. I'm going to PM Philly87 and see what he says.

 

[4X4HIGH]

Since you said you removed the ignition module that mean you replaced it with an MSD 8861 wire harness correct? This harness is what plugs into the magnetic pick-up wiring.The small red wire should now be attached to the keyed 12v wire that USED to be plugged into the distributor cap. The orange wire connects to the B+ of the distributor cap while the black wire connects to the C- of the distributor cap. You will also need to hook up a ground wire to the engine from the distributor cap.

I have all this info from a book that Phil gave me a couple years ago that is strictly nothing but wiring diagrams for all of MSD's products.

 

[Chevy305]

What/where is this gray wire?

The gray wire it the output for the tach. The ECM connects to this for its RPM signal reference.

Ok, I think I know where your problem is. The small red wire from the MSD box should be going to the 12v keyed wire that USED to be hooked up to your distributor cap B+ terminal. The orange wire should be THE ONLY wire hooked up to the + coil terminal and the black wire should be THE ONLY wire hooked up to the - coil terminal.

The small red wire is going to the old keyed power wire for the dizzy that connected to the BAT terminal.
There are only 3 wires currently connected to the dizzy. Orange wire is connected to the B+ terminal, the Black wire is connected to the C- terminal, and the GRD in the middle is grounded to the intake manifold.

 

[Chevy305]

Since you said you removed the ignition module that mean you replaced it with an MSD 8861 wire harness correct? This harness is what plugs into the magnetic pick-up wiring.The small red wire should now be attached to the keyed 12v wire that USED to be plugged into the distributor cap. The orange wire connects to the B+ of the distributor cap while the black wire connects to the C- of the distributor cap. You will also need to hook up a ground wire to the engine from the distributor cap.

I have all this info from a book that Phil gave me a couple years ago that is strictly nothing but wiring diagrams for all of MSD's products.

That is exactly how I have it hooked up.

 

[4X4HIGH]

The gray wire it the output for the tach. The ECM connects to this for its RPM signal reference.



The small red wire is going to the old keyed power wire for the dizzy that connected to the BAT terminal.
There are only 3 wires currently connected to the dizzy. Orange wire is connected to the B+ terminal, the Black wire is connected to the C- terminal, and the GRD in the middle is grounded to the intake manifold.

What year is this rig anyways?

 

[JDNobodi]

I can confirm the gray wire is tach output.

The 7531(s) I have worked on have the gray wire and the plug in the box.
The new 6a and 6al now have the gray wire. I don't think the boxes have the plug on the side of box anymore.

 

[Chevy305]

What year is this rig anyways?

Its a bunch of different years, lets call it '84 with a custom wiring harness and FAST Ez EFI

 

[cybrfire]

Did you get the box new?

MSD has always done an awesome job with me. I recommend them above all else for this type of thing and Philly87 is as stand up as they come.

 

[JDNobodi]

I would say put the HEI module back in and see if it runs.

 

[Chevy305]

I'm going to wait to talk to MSD tech before I pull the box incase they have any more insight. But I'm betting on the box being bad

 

[cybrfire]

I started out with a used box and there was a really simple way to test the box. Mine was bad but as I said, it was used.

Process seemed like what fordum was talking about.

 

[Philly87]

Chevy305,

Sorry I didn't see this until today. Nothing sucks worse than having to wait until Monday to get a response and I apologize.

Furdum and a couple of the guys here are exactly right about the spark test by shorting the purple and green wires together at the box side to see if you get spark.

To do this on an HEI without a coil wire you need to take the cap off and bump the motor over until the rotor is pointing at one of the terminals on the distributor cap.

Reinstall the cap and pull the corresponding plug wire off of the spark plug end and lay it close to ground. When you short the purple and green it will fire the coil to the rotor, rotor to the terminal on the cap and on through the plug wire to ground.

Keep in mind you have to short these wires quickly in order to get several sparks. You may also try running the same test with the white wire by shorting it to ground to make sure you know what you're looking for. Easiest way with the white wire is usually to scrape it across a metal surface to get multiple sparks.

I PM'd you with my work phone number or give me a number I can call you at and I'll gladly give you a shout so we can get this going for you.

-Phil

 

[Chevy305]

Thanks for the reply!
I have already called the tech line this morning and they agree that the box is bad. They said there was a batch of bad boxes that went out so they have no problem replacing it. Unfortunately my cell phone kept dropping the call (several times) so I couldn't be connected to the next person who was supposed to handle the shipping and claim info. So I called up JEGs where I bought it and told them the story, they said no prob and sent me a return label to my email. I've already pulled the box and put the ignition module back in and have my truck running again. Now just gotta box it up and send it off.

 

[Philly87]

Is Jegs going to replace the unit for you?

If you have any more trouble let me know and I'll get it handled.

-Phil

 

[Chevy305]

Is Jegs going to replace the unit for you?

If you have any more trouble let me know and I'll get it handled.

-Phil

Ya JEGs is going to replace it. I tried to call you to explain the situation better but got your voicemail a few times. Doesn't matter, the ball's in their court now.

 

[Philly87]

Ya JEGs is going to replace it. I tried to call you to explain the situation better but got your voicemail a few times. Doesn't matter, the ball's in their court now.

Sorry bout the voicemail. Some days it's hard to catch me at my desk or not on the other line. Leave me a message next time and I'll call ya back.

Again if there's anything else I can help with let me know.

-Phil

 

[nsxxtreme]

Is Jegs going to replace the unit for you?

If you have any more trouble let me know and I'll get it handled.

-Phil

Jegs is really easy to do returns with. I've had to return things to them and was always impressed with how easy they made it. I hope they keep this up and dont change things later on down the road. For now they have earned my buisness and I will keep going back to them. They really stand behind the products they sell.

 

[Chevy305]

Second install attempt

I'm bringing this thread back as I have tried to install another new 6A box and its still giving me the same problems

I called MSD tech line and they reconfirmed I have it wired correctly
Then they put a supervisor on and he said to check my magnetic pickup. He said it should be between 900-1000 ohms. He said if it checks out then the box isn't getting enough voltage. So after I got off the phone I tried what he said and I got 829 ohms and 12.29 volts at the box. The magnetic pickup is slightly low for what he said but to confirm I went on MSD's website and it says that a Street Fire HEI should have between 660 and 900 ohms. So is my magnetic pickup bad? I don't think it is because the engine runs fine without trying to use a box. Is it possible that I have ANOTHER bad box?

HELP PLEASE