Need help with voltage checks after upgrades

[Hop Head]

I need some troubleshooting help with my 69. A little background: I just completed several upgrades that include the following.
Ammeter bypass
new m/h engine harness which 70's style voltage regulator
master kill switch
120 amp alternator

I just put juice to the system and made a few quick voltage checks and with the key in the run position, I'm seeing 4 volts across the +/- posts on the coil. (That doesn't sound right to me)
I have almost 12v at the blue wire on the voltage reg. 

I bypassed the voltage regulator by connecting the blue and green together and still see 4v at at the coil.

Anyone have any tips on where to start tracing voltages?

Thanks, Russ

[Pete in NH]

Hi Russ,

Can you start the engine and does it run? What ignition system are you using?

The coil voltage and the alternator voltage regulator are not really directly connected. 12 volts on the blue regulator wire is correct. This blue wire and 12 volts should also connect down to one field connection on the alternator. The other wire, a green one, should connect the other field connection to the regulator. This all assumes that you have upgraded to the 70 on up alternator regulator system that your new wiring harness supports. The original 69 system was a single field connection alternator and the older single field connection alternator. So, did you upgrade both the alternator to a 70 on up type and the regulator to the later electronic type?

[Hop Head]

Hey Pete.  No, it won't start.  The set-up is mopar orange ecu with new style volt reg.  As a sanity check, here is what I have connected to the coil.  Pos post has blue wire going the the volt reg.  Neg post has black/yellow wire going to ecu.
And one additional wire for the tach.

I may have found a mistake.  My +coil blue is going to the VR.  Not the Alt like you said  It looks like I need to swap the two blues.

Thanks and I'll let you know what I find. 

[Pete in NH]

Hi Russ,

For the orange box ECU if you are using the Chrysler ECU harness, the Black wire goes to the coil -. The blue wire goes to the side of the ballast resistor that has the blue wire that also goes to the voltage regulator and one of the alternator field connections. The green wire is not used. The coil + goes to the other side of the ballast resistor and that side should also have an existing brown wire on it.

Good luck and let me know how things work out.

[Hop Head]

Thanks for the info.  I did have the correct connections.  But one question on the alt wires, my harness has a black and a purple wire that goes to the main stud, but with the bypass wire I ran straight to the relay, I did not hook up the purple wire to the horn relay. Do I need to make that connection? 
One other question, my schematic shows a wire going from the neg coil post to the distributor. I have two wires coming out of the dist which go to the ECU, can I assume that's correct? 

I hope I can figure this out, it shouldn't be this hard! But I really appreciate your help!!!

Russ

[Pete in NH]

Russ,

Yes, the two wires with the plug from the distributor should go to The ECU. The purple wire for the horns should not keep the engine from starting or running.

What 120 amp alternator are you using and can you describe exactly how you did the ammeter bypass?

[Hop Head]

Hey, I installed the Denso 120 from Mancini racing. As far as the bypass goes, here is what I did.
Ran a 6 ga wire from the alt stud to a 100 amp fuse then to the starter relay.  From the relay I ran a 8 ga wire to a 80 amp maxi fuse to the welded splice inside the car. I eliminated the black and red wires from the ammeter to the bulk head connector. I also installed a remote maser disconnect switch between the positive battery wire to the starter. And added several ground wires based on info I read from Ron Francis tech tips.  I also did the volt meter conversion from the forum folks. 
So, lots of changes at once, I was hoping everything was done correctly.  Oh yeah, plus I'm using the M&H engine harness with the electronic ignition modification.  I also changed the coil to a MSD blaster with the 2 prong resistor that was supplied with the coil.  Let me know if all that sounds right to you.  And do you think I still need to make the connection to the horn relay. 

Thanks again and let me know if you need any more info....   

[Pete in NH]

Russ,

The ammeter bypass sounds right. I'm not sure about the MSD coil and ballast resistor on an orange box ECU. The ballast resistor for the orange box should be 1.2 ohms and the coil is meant to be a standard Chrysler ignition coil. I don't know anything about those MSD coils but, I think some of those systems are high energy capacitive discharge systems. If they are that coil may not be suitable for the orange box ECU.

[Hop Head]

Yes, good point.  I'll check the resistance of the new resistor. The old set-up had a Accel super coil on it, and I might put that back on to see if it makes a difference.  I did notice the orange box got very hot when I had the key in the run position and was doing some voltage checks. I may have fried it. If I need to replace it, should I go with another orange box? If I remember correctly, mopar has a chome box that may be better suited for high output coils. I'll have to do some surfing on that.  Anyway, I think I'm going to take the weekend off and clear my head. I don't want to get to frustrated with this.  I'll let you know when I jump back in.  Let me know if you have any other checks I should make.
Thanks again, and have a good weekend....

[Hop Head]

Hey Pete. Well things are looking pretty good. I replace the orange box and everything seems fine. I let it run for several minutes and checked some key areas where I made splices and everything was nice and cool. Now I need to install the gauge cluster and hopefully everything will work. Just thought I'd let you know, and thanks again for the troubleshooting help.

Russ

[Pete in NH]

Russ,

Glad to hear you have things working again. It wasn't a good sign the old orange box was getting so hot. I guess something may have been damaged with the possible miss wiring. Good luck with the instrument panel install