Mopar Muscle Association UK

Had an afternoon on the New Yorker which has thrown up a few questions for our resident electrical Gurus please...

Right, just fitted my car with HEI, a constant 12V Lucas coil and ditched the ballast resistor...ok so far.

Tried starting her...turns over, wont start. Out came the meter and I have found that since my upgrades, I have lost the 12V feed to the coil. It was a brown wire from the ignition switch that ran to the ballast resistor then to the coil. I have just taken the resistor out of the circuit and the brown wire now runs straight to the positive side of the coil. Problem found....

Next, I ran a hotwire straight from the battery + to the coil +....starts and runs OK. Unclip wire, engine stops. Just confirmed lack of 12V feed in RUN position. Used meter just to confirm no feed in START position either through that brown wire though the switch works with the hotwire on.

Lastly, with the engine running and the hotwire in place, I can click the ignition switch back and take the key out and it will stay running.

Just to add to the confusion, my wiring diagram doesn't resemble the start circuit colours at all and my eyes are going wonky trying to trace wires to the relevant terminals in the bulkhead connector. I have removed a double terminal ballast resistor but my wiring diagram shows a single one. I have effectively taken the brown live feed from the resistor (I assume the run feed) and wired it straight to the + on the coil. The HEI unit is also fed from the + on the coil so without the original wire having 12V, neither has the HEI unit. I have run the green FIELD wire straight from the alternator to the - FIELD terminal on the voltage regulator, again just simply bypassing the ballast resistor. The Blue wire from the ignition switch now splits and one section runs to the IGN pin on the VR and the other to the + FIELD terminal on the alternator (the one nearest to the stud)

The ballast resistor was wired as follows:

LEFT SIDE (top terminal) BLUE/ YELLOW TRACE (12V feed to old ECU)
LEFT SIDE (bot terminal) BLUE (+FIELD terminal ALT and VR)
There is a black bridge wire top to bottom

RIGHT SIDE (top terminal) BROWN (to ignition)
RIGHT SIDE (bot terminal) GREEN/ RED TRACE (- Side of coil???)

My questions are;

1. What am I doing wrong? (ha ah...would help to know though)

2. What is the correct wiring for the START / RUN feeds into the new system?

3. Is there a way that Im missing to get 12V to the coil through my current setup?

The car runs so Im happy that the HEI and VR are wired correctly, Im just confused with the 12V feed in START and RUN positions?

Cheers Steve

Steve, I don't have my wiring diagrams to hand but I thought the blue wire was the main 12v feed from ignition. I'll check tomorrow and get back if no one can help.

Ah...you might have something there Miles....I have decided to check the wiring diagram for my Polara...its MUCH simpler. Seems like there is a big change in complexity between 68 and 72!!!

It looks like I need to join theblue wire from the ignition side of the VR into the brown wire and the + side of the coil. May give that a go tomw

Cheers Steve

Progress....thanks Miles....I have connected the BLUE live feed to the BROWN feed and both into the + on the VR and and we have power to the coil! Starts fine.

I haven't checked if I can still take the key out and leave it running as the heavens opened. A job for tomorrow

CheersSteve

Sweet! That means I know how to wire mine up correctly now😏

Glad you have made progress!!

Thanks Pete, getting there....very slowly!

I will do a wiring diagram when I have done some more tests to make sure all is ok....one simple one that takes in both of the attached diagrams and the bypass of the ballast resistor

cheers Steve

if your ballast has one connector at both ends. connect the wires from each end of the ballast together

if your ballast has 2 connectors at both ends

connect the left hand a right hand top connectors wire's together

and then connect the left hand and right hand bottom connectors wires together

the only thing that wanted lower voltage was the coil and the ignition box

neither are there anymore so the 12 volts to all stays.

Dave

if your ballast has one connector at both ends. connect the wires from each end of the ballast together

if your ballast has 2 connectors at both ends

connect the left hand a right hand top connectors wire's together

and then connect the left hand and right hand bottom connectors wires together

the only thing that wanted lower voltage was the coil and the ignition box

neither are there anymore so the 12 volts to all stays.

Dave