Factory/dealer service manual electrical schematics

[Railroadrider]

So... this project of ours seems like it's turning into a lifetime project. Not really, but it has been 5 years now. We live 1000 miles apart and I only get here a couple times a year. I know we haven't posted anything but I have been lurking the whole time.
The car is back together. All the updates we wanted to do are done. We've run into a few electrical issues, mostly ground related. It is, after all, a 50 1/2 year old car that spent a few years in Minnesota, North Dakota and Colorado.

Now to our current (total pun intention) problem. In the process of putting all the wiring back together under the dash, one of us accidently plugged the tach feed onto the accessory terminal on the fuse block, which fed 12 volts into the negative side of the coil. The car was running prior to this point. In trying to figure out what we had destroyed I found that the wiring diagrams have some issues. Wires, from the ignition circuits, that go nowhere (according to the schematics) was the most confounding. For instance, the IGNITION 2 wire from the STARTER IGNITION SWITCH, is a dead-end at terminal X at the bulkhead connector. I'm presuming these crazy terminal markings, that go from a letter designation on one connector and a numeric designation on the corresponding connector are just like some aircraft connections, where A = 1 through Z = 24, leaving out I and O. What I wish to know is, has anyone found a GOOD wiring diagrams source? My son found one source on eBay, pjsautolit. It's only $16 with shipping but is it reliable?

Damage so far is we fried the ECU. Our present problem is the motor won't run when you attempt to start it with the key. It WILL run when started with an external bypass switch and the key in the RUN position.

 

[70chall440]

Not sure what car you are working on but I have used the factory wiring diagrams for years without issue, yes they can be a paint to use sometimes but once you figure it out they are good. Without looking at a diagram I believe Ignition 2 goes to the ballast resistor.

Does the engine turn over with the key and just doesn't start? If this is the case than I believe you have a problem with the Ignition 2 (run) wire making contact.

 

[Railroadrider]

1970 Challenger w/small block is what we are working on. We THINK we fixed it but have to reassemble the car again to test it out.

Basically we were wondering if there was a better wiring diagram that could be purchased. And if so, where from? The factory one leaves a bit to be desired as it shows wires going up to the bulkhead but not coming out from the bulkhead. Only a couple wires are this way but still...

Thanks

 

[70chall440]

The way Ma Mopar did their diagrams was in segments, so the instrument cluster/interior diagram will shot the wires going into the bulkhead, then the engine diagram shows where it comes out and where it goes which I am sure you know. Also, I find it very helpful to print off and tape together corresponding diagrams such as figure 9 on 8-96 and figure 10 on 8-97 aligning the wires that cross over.

Anyway, to answer you question, I have seen some colored versions out there but they are all just reprints of the original. Anything you see for sale online is typically just a reprint. Perhaps there is something else out there but I haven't seen it but then again I prefer the factory ones.

 

[Railroadrider]

Moving from diagram to diagram isn't really the problem. The problem comes in when a wire go from inside (or outside) the engine bay or passenger compartment. Understand, I did this same job, basically, for 20+ years in the military except, of course, on aircraft. I'll give you a for instance and then maybe one of you can tell me where I'm going wrong. Page 8-96, Ignition 2 (I'm pretty sure our problem is SOMEWHERE in this circuitry) goes to the bulkhead connector, pin 22. Pin 22 SHOULD become pin X on the engine bay side . Problem is pin X has no wire according the the schematic(pg 8-89). This is only one example. There are only a few but all it takes is a couple to really make things difficult.

 

[70chall440]

Moving from diagram to diagram isn't really the problem. The problem comes in when a wire go from inside (or outside) the engine bay or passenger compartment. Understand, I did this same job, basically, for 20+ years in the military except, of course, on aircraft. I'll give you a for instance and then maybe one of you can tell me where I'm going wrong. Page 8-96, Ignition 2 (I'm pretty sure our problem is SOMEWHERE in this circuitry) goes to the bulkhead connector, pin 22. Pin 22 SHOULD become pin X on the engine bay side . Problem is pin X has no wire according the the schematic(pg 8-89). This is only one example. There are only a few but all it takes is a couple to really make things difficult.

Ok I get what you are saying, look at page 8-90, cavity 22 goes to the BR which is correct. I know is says "hemi engines" but I think when they did these manuals the car was still in development. I have frequently went back and forth from the hemi engine diagram and the "Except hemi engine" diagram.

 

[NoCar340]

Pin 22 (J3 14BR, "IGNITION 2" on the interior side) should ultimately go to the 2-wire connector at the ballast resistor. The other (blue) wire in the ballast connector goes to coil (+). The brown wire only goes 12V+ during cranking; it bypassed the ballast resistor for quicker starting. It goes open circuit when the key is released.

 

[Railroadrider]

Thanks for everyone's inputs. The motor is running again. We figure one of two things happened. A) while messing around under the dash (isn't that fun?) we inadvertently disconnected something that we couldn't see, or B) when we backfed the +12 volts to the negative side of the coil we caused a carbon deposit on a connection somewhere. In the disassembly/troubleshooting/reassembly we accidentally cleaned said connection. As we zip tied the wire bundles the car was started after each section to make sure nothing was pulled loose. Good Lord the exhaust note on this thing is SWEET!
Anyway, we are now in the put the rest of the car back together mode. Got the rear seat side panels and the seatback reinstalled. Seatbelt installation is next, including the three-point retractable front belts.

 

[nervouswrecks]

I want to interrupt your discussion with a similar topic. On my factory 1970 Hemi Barracuda engine wiring diagram, above the alternator are what look like two bulkhead connector terminals, each one numbered 1-6. I can't find these on my car. My bulkhead going into the passenger area looks like the bulkhead structure for a 440. Where are these two [1,2,3] [4,5,6] connections inside the engine compartment of my supposedly stock 1970 Hemi 'Cuda? Factory manual, page 8-131, fig. 14 .

 

[Chryco Psycho]

Why not start a new thread ?
I don't have a wiring diagram handy to look up the connection you are reffering to sorry .

 

[nervouswrecks]

Why not start a new thread ?
I don't have a wiring diagram handy to look up the connection you are reffering to sorry .

Thank you for the 'manners' tip. I'll try that, having never been on this site before.