Well, this is gonna hurt. Rewire has begun!

[TexasStroker]

Coming along great!  Thanks for the insights on the fuse pulling...it is hard to gauge from the RF pics if it is tiny, or you've got more space to work with.  Wise move investing extra time in the connections and keeping everything tidy.

[Vegas_Nick]

I have been working on the same on my 74. I built my own harness though.



So far so good.

I hear ya on sketchy things! I found an old extension cord ran to the fuse block from who knows where. It had been cut off long ago and left dangling in there!

[MoparRocks]

Ok,

So got off work a bit early today and was messing around a bit in preparation for the interior tomorrow. Trying to work out the heater wiring and I have a question. The car had AC, but when I bought it none of the under hood stuff was connected and I decided to just remove it all. Figured it would cost a fortune to get it all hooked up and charged and running. That said I have no plans to put it back in so I don't see the need to hook up any of the ac wiring. However I am slightly concerned the heater won't work properly so just for clarification.







Based on the schematic I found online for this, the long black plug is MOSTLY AC related. However,
The black with white stripe is the power in from the fuse box
The light green is the clutch feed
The brown is linked to the 3 prong that attaches to the heater switch and is for low heat
The tan also links to the heater switch and is for the blower
The dark blue is also labeled clutch.

So I should be able to just cut out the two clutch wires as I am not running the AC correct?

Also, there is a dark green wire from the plug that goes to the heater switch labeled blower motor. This should connect to the motor under the hood correct? Because I also have a dark green wire coming out from behind the dash someplace with the rest of the wires that go to the heater box behind the dash. Not sure if they were both connected to the bulkhead or not. So do I connect the wire from the switch plug to the blower motor u doer the hood? Or to the wire coming out behind the dash?

[Nacho-RT74]

Will post better info about what you have at this moment later, however an advance...

The AC harness is a separated one from the rest of harness. Just need to remove the black traced white wire from the AC control plug, and the related green and blue wires from the bulkhead. The harness will come out from the main harness in one piece.

Then if you get a Heater harness you can simply relocate that black traced white wire into the heater harness plug, get a heater control switch unit and you'll be done on that side. Reinstall the blower wire from the heater harness ( which is the one what feeds the blower ) to the bulkhead conector, and done there...

Next diff to deal is the AC and heater boxes differences. Firewall is different too.

With all the investment you are doing, why not to get the parts you need to get completed what you already have on car?... just my 2 cents.

Need to note on AC cars, the heater works just at one blower speed, which is just a bit higher than the lower AC and VENT speed

[Nacho-RT74]

ok here is how it is wired and how it works... ( check diagrams )


Wires at Control unit plug:
light green traced is the input for the compressor clutch... attaches at an acc power feed provided by the main harness with a bullet terminal which comes from fuse box

blue is the output to compressor... runs to bulkhead

Black traced white wire is the input to the BLOWER, comes straight from fuse box

Brown sources the resistor block at A/C box just for HEATER and DEFF speed... its a fixed speed. These functions are not affecte for the blower lever

Tan wire, is the output to blower lever switch


Now wires at blower lever switch

Tan... input to the lever switch but you can note is spliced and this splice RUNS STRAIGHT TO RESISTOR BLOCK... this makes the low speed actually DOESN'T GO THROUGHT the lever switch, but reachs straight the resistor block and it means if you remove the lever switch, when you turn on the AC ( or max AC ) and VENT funtions, the low speeds is A DEFAULT speed. When the lever switch is connected, the Low position is just like it is in OFF, taking this input source to nowhere inside.

light green... it takes to the mid speed at resistor block. The switch takes the tan wire source and redirecting to the light green position to feed mid speed resistor.

Dark green... it goes straight to the bulkhead cavity to feed the max speed. switch takes also the Tan wire input to select the max speed point on switch


Wires at resistor block

Tan..., low speed,  comes from the lever switch splice... as mentioned previouslly, is allways hot when setting AC or Vent positions and is the default speed.

light green... comes from lever switch, mid speed, going throught the switch points.  Even the resistor block is ALLWAYS hot at TAN input, by ohms law, the mid speed selected at Light green is the one what will source the blower. Remember THE ohms law, the load will go through the smaller resistance it finds

Brown... is hot when set Heater and Deff funtions... its the fixed speed for them. No blower lever for them

Dark Green... is the output from the resistor block to feed the blower once the speed or function is selected. you'll find THIS OUTPUT IS SPLICED INTO THE SAME WIRE COMING FROM SPEED LEVER... yes of course, because the max speed is a direct source from lever. Once again, this wire splice will take the max power it comes from by ohms law... if max voltage from lever speed at AC or VENT, then won't matter what comes from the resistor block... which usually is the lower lever speed because is the default source.


attached... the 71/72 acc wiring when you'll find the AC section and what wires use from the main harness

and next diagram is the underdash harness where you see ilustrated the heater wiring when the car is just heater ( which is the basic equipment ), using just the Black traced wire to feed the Heater system. Resistor block for heater is there too. As mentioned, when car got AC, this black traced wire is attached to the AC control plug on AC harness. This wire is allways present on ALL underdash harnesses

Need to note these diagrams are 71... 72s got some differences, related to warning buzzer systems ( just to let you know ) and wiper switch plug

[MoparRocks]

Thanks Nacho! You are the man!!

One more thing I am having difficulty with is the wiper motor. None of the diagrams I have found say which pins are for what function on the motor pigtail. On the new Ron Francis wiper switch I have:
Motor Low Speed
High speed terminal
Park terminal
And battery positive with two pins so I am assuming one in from the fuse box and one out to the motor.

On the wiper motor pigtail I have 4 wires.
Red
Brown
Green
And blue
Assuming red is battery positive but which wires are low, high, and park?

[MoparRocks]

Well once again life and daughter slowed my progress today. Got the heater stuff all figured out. Still need to work out the wiper wiring above. Got the gps unit for the speedo installed and wire run. Started coraling and straightening out the rats nest of spaghetti under the dash and managed to get all the wiring fed back to the trunk that needs to go to the back. Also went ahead and swapped out the cigar lighter in the ashtray for something a bit more modern after giving it a few coats of hammered paint to clean it up.

[Nacho-RT74]

I'm actually not aware about the color codes BUT the back of the switch got the codes( also the plug ), where:

W is washer is ine of the browns... can recall if traced or not
B must be battery ( actually from keyed source ) should be pink
P is parking ( and is hot while ign key is on and switch is off ) dunno if red or blue.

Then we have A, F1 and F2. Would need to check it.

[MoparRocks]

Well made some solid progress this weekend. I think most of the big stuff is done and I managed to get most of the wiring tidied up. Still have to finish the tail light rewire then I should be about done with the electrical. Managed to do some testing as well and so far pretty much everything appears to be working. For the first time since buying the car the fuel gauge works!!!

Here are the pics from today.
















Still have to figure out the wiper motor wiring, finish re wiring the tail lights, install the amp and wire the rear speakers, reinstall a few interior panels, and do the headers and new exhaust. If all goes well I hope to be able to fire it up at the end of my next two days off.

[mopar0166]

Nice Work

[MoparRocks]

Hey all,

Got sidelined by the flu last week but I got the majority of the wiring all wrapped up now. Everything appears to be working correctly. Dome light and foot well lights come on when I open the door and off when I close it. Blower motor runs, gauges work. Headlights, turn signals, brake lights, parking lights, etc.

Few last odds and ends to resolve.

Still need to figure out the wiper motor wiring but I don't drive in the rain if I can avoid it anyway so not a huge priority.

I did notice that for some reason my reverse lights are on with the ignition. Now I haven't started the car yet or run it thru the gears as it's still on jackstands and I still have to complete the exhaust. But just with the parking lights or headlights on, the reverse lights are lighting up. Wondering if I wired the neutral safety switch wrong? I ran one wire to the starter relay, one to the reverse lights, and one to an ignition hot source from the fuse box. Possible I have the pins wrong?

[MoparRocks]

Ok so got the reverse lights resolved. I just unplugged the connector on the neutral safety switch and flipped it 180 degrees.


Finally hit the big moment of truth and tried to fire it up.

No spark!

So it's either the MSD, the Perronix, or something is wired wrong going to them. I double checked my wiring and I have the two wired together correctly per the MSD instruction sheet. I fed the MSD off the coil feed wire in the wiring harness as it is ignition hot which is what the MSD needs. But yeah, no spark. Any thoughts where to start checking?

[Nacho-RT74]

Ok so got the reverse lights resolved. I just unplugged the connector on the neutral safety switch and flipped it 180 degrees

Something is wrong! It should work in any position

[MoparRocks]

Ok so got the reverse lights resolved. I just unplugged the connector on the neutral safety switch and flipped it 180 degrees

Something is wrong! It should work in any position

That's what I thought as well. But I flipped it over (it's the 3 pin) 180 degrees from where I had it and the reverse lights no longer come on with the running and headlights. To be fair I didn't actually check to make sure they come on with the trans in reverse but I was more concerned with the no spark issue. That said it only cranks in park and neutral. Won't even crank in any other gear.

Personally I'm thinking it's an issue with the petronix conversion. I rechecked all the wires to and from the MSD and everything is wired as it should be. I kind of just snapped and ordered a MSD ready to run pro billet distributor and I'm just gonna go ahead and throw that in. It's been one of those days. I also caved on my exhaust plans after spending half the day trying to make it work the way I wanted. But hey, I guess at least it's looking good under the hood.








Oh, and a shot of the tail light wiring I did

[TexasStroker]

Off topic, but is that vacuum line red, or orange?  It looks orange and I'd always toyed with the idea of doing that under the hood just as a change of pace, but was never able to find an "orange" or red that looked orange as you so often have to settle for when trying to do orange.

Very basic on the cranking/spark, but a lot of issues I've had in the past are solved with a fully charged battery and checking/cleaning grounds.

Hopefully it is a quick and easy fix.

[MoparRocks]

Off topic, but is that vacuum line red, or orange?  It looks orange and I'd always toyed with the idea of doing that under the hood just as a change of pace, but was never able to find an "orange" or red that looked orange as you so often have to settle for when trying to do orange.

Very basic on the cranking/spark, but a lot of issues I've had in the past are solved with a fully charged battery and checking/cleaning grounds.

Hopefully it is a quick and easy fix.

It's red line and I did it for the same reasons you mentioned. Just for a splash of color contrast under the hood. Got the kit from Amazon with several different sizes. Used it for the line to the overflow bottle as well. It's all silicone. Curious to see how well it holds up.

Battery is definitely fully charged. Been sitting with the solar panels hooked up to it the whole time it's been under construction. I also know the grounds are good. That's one area I went all out on during this. Cleared paint down to bare metal on every single point and coated with dielectric grease. I also did several heavy gauge grounds. Battery to block, block to chassis times two in two separate areas, battery to chassis as well. I kinda felt when I installed the petronix that it may be an issue. I followed the directions to the letter but I just wasn't thrilled with it putting it in.

[MoparRocks]

Btw, can someone tell me what the hell that black tube is on the passenger fender? Nothing was hooked to it when I got the car IIRC. It goes down to a line below the car on that side as well but I haven't tracked it all the way back to its other end. Can be seen in the first and second picture in my last post above.

[Vegas_Nick]

Btw, can someone tell me what the hell that black tube is on the passenger fender? Nothing was hooked to it when I got the car IIRC. It goes down to a line below the car on that side as well but I haven't tracked it all the way back to its other end. Can be seen in the first and second picture in my last post above.

I can't see it clearly but it appears to be the gas tank vent line that should be going to an emissions canister.

[MoparRocks]

Well, major milestone today. IT'S ALIVE!!!!!!

I got the MSD ready to run pro billet distributor in. Quickly discovered I somehow had screwed up the plug wire routing before and had them out of order so I fixed that. Went to turn the key, and nothing again. So I broke out the multimeter and discovered that the coil wire I was using for ignition power to the MSD box and distributor drops to no volts during cranking. There is the problem. So per the instructions that came with the distributor, I wired in a relay to ensure a solid 12 volts straight from the battery to the distributor and ignition box. Trie to trigger it with the coil wire, but no joy. So instead I installed a hidden toggle switch run off one of the select a circuits that is always hot. Added bonus is I now have a hidden kill switch for anti theft measures. Switch on, turn the key and she fired right up.

Also verified that the reverse lights come on in reverse, the electric fan kicks on at temp, etc.

So my issues now are:
Major static in the rear speakers with the engine running despite the fact that I ran the rcas and power wire down opposite sides of the car. Thinking I may need to redo the speaker wires from the amp to the 6x9s as those do cross the power cables in the back.

The idle is a bit rough and lopes a fair bit. However I plan to get it dyno tuned with all the ignition changes I made and sadly I'm not super familiar with timing and carb tuning. Just need to get it running well enough until I get it tuned. Also I noticed I can turn the distributor pretty easily by hand. The factory hold down has teeth in it that engage in slots on the base of the stock distributor, the MSD however does not have these slots. Probably need a new hold down that's flat on the tips.

And finally, I think the neighbors are gonna hate me. It's LOUD with just the purple horny header mufflers, but I like it!

[frank1966]

Nice, i did the same. I gutted all of original wiring and installex 24 7, msd all in one, one wire alt, dakota digital dash.
Did connect the heat yet.

[MoparRocks]

Well I guess a final update is in order.

Only thing I haven't figured out is the wiper motor, but it's low priority as I don't drive her in the rain if I can help it.

Spent a lot of time trying to get it dialed in but I just couldn't get it tuning well. So I went ahead and took it to the local dyno shop figuring I just didn't know my way around a timing light and carb adjustment screws as well as I thought. I had it running well enough I was able to drive it there. Mechanic hops in for a quick drive before pulling it onto the dyno and it stalled out in the driveway.  He spent some time trying to figure out why it wasn't running right. Finally it got to the point that I left it there. Mechanic called me next day and come to find out the harmonic balancer was shot. It's the old two piece design and it had spun out so the timing was completely screwed. He's replacing it and then he is gonna dyno tune it to get it dialed in.

And yes I got the heater hooked up and working. Then went out an hour later to find a nice green puddle on the floor mat. So yeah, bypassed the heater core again. Looks like that will be the next project.