1973 Duster Electrical Issue

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1972trucks

1972trucks

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I have a 73 Duster 340 that I completely rebuilt. It is all numbers matching. I kept the original wiring harness. The car starts, run, and drives. I don't have anything electric except for the front running lights. I have the left side marker light and the left fender top turn signal. I do have the wipers too but that's it. No rear anything. I am not an electrical guy so my knowledge is limited. I have replaced the turn signal switch which I have been told controls all of the lights. Any help would be appreciated before I take it to a shop.
 
Remove the drivers side kick panel and look for some connectors.

They are the connection from the dash / steering column to the rear of the vehicle.

Check for voltage etc.

Get a wiring diagram (mymopar.com or classiccarwiring.com)

And start tracing wires.
 
For the rear lights problem, I also think the big connector into the driver side kick panel can be the fautive.

rear connector.jpg
 
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Go to Mymopar and download the FSM, it should give you the wiring information you need.
 
1972trucks said:
The car starts, run, and drives. The car's electric don't work except for the front running lights, the left side marker light and the left fender top turn signal.The wipers work too.
Click to expand...
Edited to clarify. Tell me if I misunderstood.
1972trucks said:
No rear anything.
Click to expand...
No lights, brake lights, or reverse lights.
correct?

No dome light
Correct?
1972trucks said:
I am not an electrical guy so my knowledge is limited. I have replaced the turn signal switch which I have been told controls all of the lights.
Click to expand...
If your willing to learn, you'll soon know more than whomever is telling you such things.
The turn signal switch does control brake lights and turn signals. But not tail and reverse lights.
 
Mattax said:
Edited to clarify. Tell me if I misunderstood.

No lights, brake lights, or reverse lights.
correct?

No dome light
Correct?

If your willing to learn, you'll soon know more than whomever is telling you such things.
The turn signal switch does control brake lights and turn signals. But not tail and reverse lights.
Click to expand...
 
correct I don't have anything. I have the lights in the grill, fender turn signal on the top of the fender and the marker light on the left fender. That's it , no tail lights , brake lights, dome lights
 
Let's begin with the power supply.
There are two power supplies for the car.
Power flows from whichever one can supply at the higher voltage.
  • Battery can supply power at approximately 12.5 Volts.
  • Alternator will supply power at approximately 14 Volts.
Power distribution
The output wires from the battery and alternator are joined at a welded splice under the dash.
That welded splice is also a junction to feed the main circuits:
  • Key switch (wire J1)
  • Fuse box (fuses that are always hot) (wire Q3)
  • Headlight switch power for headlights (wire L1)
1686498896370.png

Dome light, parking and marker lights, brake lights, horn, all get power directly through the fuse box's hot buss.

Windshield wiper switch gets power only when the key is in accessory or run position.
Heater fan, Radio, Reverse lights, and Turn signals only when the key is in accessory or run position.
On 1973 models, the heater switch, reverse lights, and radio share a fuse and wire circuit to the turn signal flasher.

Hazzard flasher is seperate. Power is available to it even with the key off.
 
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My suggestion is to track down the problem(s) in sequence.
You can do some of this without any tools.
(A battery charger and a multimeter will be helpful if you have them but htis will get you started.)

Using the ammeter
The ammeter will indicate electricity flowing out of the battery. Needle up is none. Needle fully toward D is about 40 amps. (30 to 40 amps either way is danger zone)
With the key off, the ammeter should indicate zero until something is turned on. Then is should move.

For example:
If a lamp is turned on and the needle moves a little, it is indicating current flowing out of the battery and through the bulb.
If the switch is on and the needle moves, but the lamp doesn't turn on, then there is short circuit afte the switch. Current is flowing out of the battery but its not getting to that lamp.

In this situation the ammeter probably won't be a big help, but is worth checking because it can flag things that otherwise would be head scratchers.

A Method to Narrow Down the Problem

1. Check all the devices that should work with the key off.
Brake lights (brake pedal)
Headlight switch.
Both Feeds should work. Parking, tail and instrument feed is fused. Headlight power feed is not (circuit breaker is in the switch).
Hazzard lights (emergency flashers) If these all work, then the fuse is good.
Horn
Dome light

Check the fuses if they don't work. If you have a voltmeter or test light, check for power to those fuses.

Check the items that shouldn't work with the key off. If any of them due, then there is a cross wire short.

2. Key in accessory position
Check the items in sequence in the feed to the flashers
Heater fan, radio, backup lights, then flasher.
( Note that we've has a couple of members recently find the backup lamp cable shorted on the transmission case. )

Wipers work. So we know the switch accessory circuit is good, at least to the wiper switch.


Knowing more about which ones work and which don't, and the bulbs and fuses are OK (or not) then can get into the turn signal/brake wiring along with ht egrounding of the two filament lamps.

I'll post some links about how to trouble shoot those.
 
1972trucks said:
I have a 73 Duster 340 that I completely rebuilt. It is all numbers matching. I kept the original wiring harness. The car starts, run, and drives. I don't have anything electric except for the front running lights. I have the left side marker light and the left fender top turn signal. I do have the wipers too but that's it. No rear anything. I am not an electrical guy so my knowledge is limited. I have replaced the turn signal switch which I have been told controls all of the lights. Any help would be appreciated before I take it to a shop.
Click to expand...
Do you have headlights?

Access the fuse panel should be up under the dash on the far left. There are THREE busses in it

1 is hot all the time, supplies stuff like tail/park lamps, brake light switch, and hazard flashers
2...is hot only with key in "run" or "accessory" supplies things like wipers, heater, radio
3..Is a trick fuse for the instrument lights. More later

So with the key "off" one buss and 3? fuses off it (you can SEE them if you look at the bottom of the fuse panel) should be hot on both ends

With key "on" ALL fuses except the INST fuse on the end of the panel should be hot both ends of the fuses
 
Mattax said:
Let's begin with the power supply.
There are two power supplies for the car.
Power flows from whichever one can supply at the higher voltage.
  • Battery can supply power at approximately 12.5 Volts.
  • Alternator will supply power at approximately 14 Volts.
Power distribution
The output wires from the battery the alternator are joined at a welded splice under the dash.
That welded splice is a also a junction to feed the main circuits:
  • Key switch (wire J1)
  • Fuse box (fuses that are always hot) (wire Q3)
  • Headlight switch power for headlights (wire L1)
View attachment 1716101127
Dome light, parking and marker lights, brake lights, horn, all get power directly through the fuse box's hot buss.

Windshield wiper switch gets power only when the key is in accessory or run position.
Heater fan, Radio, Reverse lights, and Turn signals only when the key is in accessory or run position.
On 1973 models, the heater switch, reverse lights, and radio share a fuse and wire circuit to the turn signal flasher.

Hazzard flasher is seperate. Power is available to it even with the key off.
Click to expand...
 
If you need help with the service manual diagrams, there's a 1974 Master Tech filmstrip and booklet about wiring diagrams. It covers the new style of diagrams introduced in 1973 and explains all of the wire codes.
pdf version here: Browse MTSC by Model Year – 1974 – MyMopar
These later diagrams are hard to keep track of individual circuits. Use the diagram to make your own drawing of just the circuit(s) you are interested in.

Complete listing of the Master Booklets and films is here:
Master Technician Service Conference - Chrysler's Training for Mechanics
Once you know the year to look under you may want to go to back to the mymopar website to view them in pdf format.

Turn signal operation is explained in MTSC 1965, #2.
It also may be covered again in the 1970s.
 
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UPDATE. . . thanks for all of the help. I have looked at what I could and here is where I am. I have power to start the motor. I have both the two front marker lights in the grill. I have the front left turn signal, left front side marker light, windshield washers and fan blower motor. I have nothing else.
 
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