wiring harness meltdown..

[734406PK]

 Aftermarket issues! I agree, they suck! As for your bypass idea, yes i think it will work. GM has done it that way (indirectly) for years. The principle is the same and electrons don't care. As you mentioned, it's not Mopar OEM design though. Your choice on this one!

[Dakota]

Ok....anybody know how difficult it is to replace the ignition switch wiring and harness??   Any body have instructions for this? 

The best guidance available is a deconstruction video that @Cuda Cody put together for the site.  You can find it near the bottom of this page:

https://www.e-bodies.org/videos/

The video is based on removal and dismantlemnt of the column which includes accessing the ignition switch.   It'll be snug doing it in the car but it appears possible (disclaimer:  I rebuilt my steering column removed from the car, not installed).

[RUNCHARGER]

I think I've done it in the past. I seem to remember tying some string and pulling the harness through with the string is what it took. Pretty sure the harness only will go through facing a certain direction too.

[1 Wild R/T]

Wheel & coffee can off,  unbolt the column support bracket & wire guide, then T/S switch, I unplug it & just pull it out as far as I can without pulling the harness out of the upper column...  Next upper bearing out..... Remove the upper column housing.... Take the lock plate off, remove ignition tumbler & steering column lock lever... Then unplug the ignition switch & fish the harness out of the column.... It's a job.....

[chargerdon]

Still thinking about replacing the starter switch..   Watched a youtube video on how to tear down the steering column to get to it.   Looks like about 3 hours of work...  and a lot of special tools needed or at least they would help..  include a steering wheel puller, snap ring pliers, and a couple of pin puchers.   Also, watching the video, i saw that the "extra" two wires in the 8 pin connector are for the key in ignition buzzer.   The new ones dont come with it as its a switch in the steering wheel, down thru there...   So, they expect you to remove those wires from the OLD ignition switch and then put into the new one as the key-left-in doesnt come with it.   NO BIGGEE i dont have mine hooked up anyways.   So i could ignore that..   

ALso, if found several of them come with the two power wires left out of the 8 pin connector, and you can either shove them into it, or leave out and take the other side out (one of mine already is) to not use the connector. for the two power leads. 

Vansautollc has one that the wires are pulled out, and comes with a separate two wire connector and the ends to put on to the wires on the other side.   see: https://www.ebay.com/itm/Mopar-72-73-74-75-76-77-Dodge-Truck-Ignition-Switch-1972-1973-1974-1975-1976-NEW/400861329890?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649   

Or for a few bucks more i can buy one on ebay that claims it is "oem" in that it is "made by original mopar vendor".   Im inclined to buy the one from vans, because its power wires are already out of the 8 pin connector..and comes with kit for the other side.   Which i think is a great idea.   

[chargerdon]

Well the extra relay didn't help...  it still wont start off of key but i can make it start by jumper wire from battery to starter wire on ballast, or by leaving the key on run, and then jumper starter to crank at the starter relay.   (this method works best).   The extra relay to attempt to give battery to ballast will get it to start but very weakly ...   so i'm at a wits end.

One truly interesting point is that in studying the wiring diagrams found on mymopar.com for 74 challengers i found a discrepency.   The simplified 5 pin diagram http://www.mymopar.com/downloads/Dual_Ballast_5pin.pdf shows the ballast with the brown (start wire) connected to the 5 ohm side of ballast and the lead on same connector to the 5 pin ECU on the 1.2 ohm side.   Now this seems strange to me in that if you follow the wiring...  connected this way...on start you will get 0 resistance to coil that's GOOD, but 5 ohm resistance to ECU from the ganged (run) connector, and 6.2 ohm resistance (thru 5 ohm and 1.2 ohm paths) to the other pin on ECU sounds bad to me...    This seems like way too high a resistance to the ecu for starting...     My car is wired just the opposite...  the brown starter wire is on the 1.2 side and the other side (5 ohm) has the other lead to the ecu.      So, while 95% certain that i didn't cause this in rewiring the engine harness...i said what the heck...only takes two minutes...so i swapped them to agree with the diagram in mymopar.      Kept fingers crossed and with my extra relay removed, i tried starting the car....   but no start, either with the key on start...or key on run and jumpering the starter to crank...   NO Start at all...   So i put the wires back they way they were and right back to original position of no start with key, but with key on run and jumper starter relay to crank she fires right up.   

Is there a possibility the mymopar diagrams are wrong?   Can anyone look at their working car with factory electronic 5 pin ignition for me, and observe which side of the ballast resistor the brown wire goes in ??   the 1.2 or the 5 ohm side.   PS...   diagram on mymopar.com http://www.mymopar.com/index.php?pid=115 shows the 5 ohm side on the "right side" of ballast when looking at it with the "open indent on top...   

HELP...  any electricians here to explain this to me ?? 

[734406PK]

 OK, so using the brown wire to actuate a relay didn't work? Not enough power on the brown wire to even close a relay? The brown wire must be completely open?? I read in your post that the bulkhead connectors were meticulously cleaned, but i would check for voltage/amperage at the drivers side of the bulkhead connector, brown wire, just to be sure. As for the '74 wiring diagram, i will review it so  can give you an intelligent answer. 

[734406PK]

 found this diagram:
http://www.chargerr.com/Ignition/Ignition.htm

look at 5 pin electronic.

[chargerdon]

734406PK   Thanks for the link to those ignition wiring diagrams...   This one agrees with how my car is actually wired...i.e. the brown start wire goes to the post on the ballast for the 1.2 ohm side...    The one in mymopar shows it going to the 5 ohm side.    OH MAN when you cant trust wiring diagrams ...then how can you trouble shoot.    Also, when you looked closely at the two diagrams...mymopar vs the one you linked me...   the pins are different on the ecu...looks like one of them has the pins reversed..    Damn...   

Thats why i asked for anyone with factory (not converted) 5 pin ECU to look at what side of the ballast it is connected...  1.2 or 5 ohm side.   

[chargerdon]

734406PK  Also, on my attempt to bypass using a second relay..   the way i hooked it up was the new relay gets batt ground and trigger wire from the corresponding posts on the starter relay.    Then on new relay i have a heavy wire running from its sol (out post) to the ballast brown wire.   I know the relay is triggering, because i can feel it click when wife hits the key to start.   But for some reason this is different than putting brown wire directly on the battery.   Incidently with my ohm gauge i checked the new relay for amperage draw to activate it...less than 1/2 amp...     

Towmorrow, im going to take the entire harness out again, and ohm check each and every wire and trace where they go to...   For the third time...  and reclean all of the connectors.. 

[734406PK]

734406PK  Also, on my attempt to bypass using a second relay..   the way i hooked it up was the new relay gets batt ground and trigger wire from the corresponding posts on the starter relay.    Then on new relay i have a heavy wire running from its sol (out post) to the ballast brown wire.   I know the relay is triggering, because i can feel it click when wife hits the key to start.   But for some reason this is different than putting brown wire directly on the battery.   Incidently with my ohm gauge i checked the new relay for amperage draw to activate it...less than 1/2 amp...     

Towmorrow, im going to take the entire harness out again, and ohm check each and every wire and trace where they go to...   For the third time...  and reclean all of the connectors..

I may be misinterpreting the relay connection but here is a generic wiring diagram:
http://hd-dump.me/wp-content/uploads/12v-30-amp-relay-wiring-diagram-with-717-2bakvzzhl-sl1500-new-12v.jpg

Relay terminals:
30   12 volt positive power feed-(constant hot)
85   12 volt ground
86   switched positive trigger- connect to brown wire
87   normally open contact, closes on trigger- connect to ballast, brown wire
and if you have a 5 pin relay-
87a  normally closed contact, opens on trigger- not used here, leave disconnected

This should work. When the brown wire goes hot, it will close the relay contacts sending battery power directly to the ballast, same as a jumper wire.

[chargerdon]

That is essentially what i did..   

Post 30...  ran jumper wire to post 30 Batt of starter relay
post 85...  ran jumper to post 85 ground of starter relay
post  86..  ran jumper to 86 key start trigger of starter relay
post 87   ran this to the ballast resistor where brown wire goes...  ie. onto 1.2 ohm side of ballast resister.

I know the new relay is firing as i can feel it when wife turns ignition switch to start...  but car cranks but isnt starting...  it should.

Only problem i can see is that i haven't disconnected the normal brown wire from key switch...  maybe the current is fighting itself?   

[HP_Cuda]

Could your ignition switch be bad?

This is not making much sense.

[chargerdon]

Well...the ignition switch certainly could be bad..i have a new one on order..   

Did the X-tra relay as a quick work around until the new switch arrives...   By putting in the extra relay fed from the starter relay and going to the ballast i should be essentially be bypassing all the wiring in the harness, bulkhead connector, and starter switch itself for start.    It should have worked but doesn't..   but if i manually use the same extra wire to ballast straight to battery, and crank via switch the car will start...   NONE of this makes sense...im pulling my hair out and about ready to commit hairy-kari..   

[734406PK]

That is essentially what i did..   

Post 30...  ran jumper wire to post 30 Batt of starter relay
post 85...  ran jumper to post 85 ground of starter relay
post  86..  ran jumper to 86 key start trigger of starter relay
post 87   ran this to the ballast resistor where brown wire goes...  ie. onto 1.2 ohm side of ballast resister.

I know the new relay is firing as i can feel it when wife turns ignition switch to start...  but car cranks but isnt starting...  it should.

Only problem i can see is that i haven't disconnected the normal brown wire from key switch...  maybe the current is fighting itself?

Ok looks good. Check for power at 87 when the relay triggers. I think something is wrong there.