Electrical help

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Scott Paauwe

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Hi Guys, new to the forum and I'm hoping you can help. I have a bone stock 74 Duster 360. Recently I replaced the ignition with a repop and everything was fine. A friend added a tach and screwed up something in the wiring. I have removed all the tach wiring but something remains weird. I have no power to anything running off the acc circuit. so no radio, blower, signals etc. Also another odd thing is my dash lights are gone. I've pulled the fuse box and tested for power and with the ignition on there is no power to the last fuses, blower and acc. Any advice you have would be appreciated.
 
Hi, and welcome to the site.

First thing is thankyou for starting with the vehical and year, many people who have been on this site for years forget that!

Go to mymopar.com and download your cars Factory service manual, wiring diagram, parts book. All free pdf downloads.

Second go to Classic Car Wiring . Com : Home of the original color laminated classic car wiring diagram
and for about 20.00 get an 11x17 laminated colored wiring diagram.

Many of the diagrams are not 100% correct, (even the OEM have been know to have inaccuracies)

As for your particular issue, did your friend mess around under the dash and in the engine campartment?

There are the bulkhead connectors which are natirious for bad connections, they may have been bumped.

The description sound like blown fuses but who knows.

Too many possibilities when friends "help"

After you get your wiring diagrams start tracing out wires looking for where there should be power when the key is in the on and run positions.

Good luck

@Mattax @67Dart273
 
Yup I got the color 11x17 laminated diagram for my 72 Dart makes wiring problems much easier easy to read and easy to trace what wires go where
 
The laminated version is the most inaccurate of all. Stick with FSM. The radio doesn't run off the ACC fuse, your problem is elsewhere. Check all your fuses.
 
Scott Paauwe said:
Hi Guys, new to the forum and I'm hoping you can help. I have a bone stock 74 Duster 360. Recently I replaced the ignition with a repop and everything was fine. A friend added a tach and screwed up something in the wiring. I have removed all the tach wiring but something remains weird. I have no power to anything running off the acc circuit. so no radio, blower, signals etc. Also another odd thing is my dash lights are gone. I've pulled the fuse box and tested for power and with the ignition on there is no power to the last fuses, blower and acc. Any advice you have would be appreciated.
Click to expand...
When you say you "replaced the ignition with a repop", what exactly did you replace? Ignition switch, or distributor, or ignition module, or wiring, coil, or a whole aftermarket ignition system (MSD, HEI, etc.)?
 
I would start by going directly to the ignition switch connector coming out of the column. ID the ACC wire and check that it is powered up with key in either "run" or "ACC" on BOTH sides of the connector

You need to get yourself a factory manual

NOTE "start" is shown somewhat incorrectly. The Yellow and BRown are NOT interconnected. They are separate switch contacts for isolation

S2-12 Yellow is "start"
Q2-12 BlacK is your accessory feed going TO THE MAIN ACC BUSS in the fuse panel
J2A-12 Dark BLue is your IGN1 "run" ignition power
J3-12 BRown is the IGN2 "bypass" circuit to coil
J1-12 Red is the main power coming in from the ammeter welded splice
E2-20 Orange is dimmer controlled dash lighting either to shifter quadrant or "key in" light don't remember
M16A-20BlacK is the horn switch wire




74ignsw.jpg


ignsw2.jpg
 
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Scott Paauwe said:
Fuses are all good, I'm thinking it's the main wire coming from the ignition. I'll do some more testing.
Click to expand...

Hi Scott,

Welcome to the site!

There is much electrical experience here so use the search feature. Many others on here have had similar problems so the answer could already been addressed here.

One thing I ran into. Don't assume the fuses are good by looking at them, use a meter to verify.
 
Professor Fate said:
When you say you "replaced the ignition with a repop", what exactly did you replace? Ignition switch, or distributor, or ignition module, or wiring, coil, or a whole aftermarket ignition system (MSD, HEI, etc.)?
Click to expand...
Ignition switch with wiring module, all the switch pieces in the column. used the original key and tumblers.
 
OK, here I just figured out how to do this: HERE is the complete wiring section for the 74 A bodies. I also added/ uploaded it to the old "free manuals" thread, post 64

Free service manuals

Below, click the black thing in the box and select "save as" somewhere in your machine I included the "specifications" section, down below that is the bulkhead connector layouts. The diagrams in the newer manuals are / can be confusing. NOTICE that each component has an OVAL shaped window with a letter/ number in this case CI-1. This means that this is CONNECTOR in the INSTRUMENT panel number ONE Then go on past the diagrams and there are pages back there with the diagrams of the individual connectors/ components. CI is instrument, CB is "body" and CE is "engine bay"
 

Attachments

  • 74VLwirings.pdf
    1.9 MB · Views: 79
Another thing you will WANT to do on your 74 is to disable the seat belt interlock if not done

100_0894-jpg-jpg.jpg


bypassing-interlock-system.14304


Find the reset box on the driver side fender apron, and pull off the connector and look at the rear of it. You will see two "yellowish' wires which you want to jumper permanently together. This is the wire on the route to the starter relay, and if the reset circuit for the seat belt trips it will not crank

This mess was a "one year only" thing mandated by the Feds
 
Scott Paauwe said:
Fuses are all good, I'm thinking it's the main wire coming from the ignition. I'll do some more testing.
Click to expand...
Not likely. The ignition circuit only powers engine critical items; ignition, alternator's rotor, and on a '74 might be choke assist, carb solenoid and similar.
Scott Paauwe said:
Ignition switch with wiring module, all the switch pieces in the column. used the original key and tumblers.
Click to expand...
Now that's different. Most people assume 'repop ignition' means a new electronic control box. The ignition switch has a one power feed going in, but several going out. One of those going out is called Ignition (run) and another ignition (start).

Use the factory and color them in if you need.
67Dart273 pretty much has you covered in post 7 and 10.
I assume you hae a multimeter. Since you said all accessories are dead, you could disconnect the battery and check for continuity between the J1 wire to the key switch, and the Q2 wire.

Here's the basic scheme of how all the stuff connects.
This is just to help you picture how the circuits relate.
upload_2021-8-10_17-38-31.png

Several of the fuses are always hot.
Several others are only hot when the key is run or accessory.
One, usually 3 amps, is for the instrument lights.

If your car came equiped with an electric defrost grid in th erear window, the routing is a little different. For your situation, the difference shouldnt matter.
 
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The other thing is to look for cut and spliced wires. I have seen stuff where people would find a wire feed for an accessory, and instead of splicing in, they would just cut the wire altogether and attach. I have seen and fixed too much wire butchery over the years.
 
solved, the ignition switch was broken, had a crack i the plastic piece with the wiring. The only wire effected was the black wire going to the acc circuit. I pushed on it with a test light and it came on. So it was just a question of repairing the plastic.
 
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