No turn signals!!!! 72 Duster

[DusterDeano]

Hello everyone, I know there a probably a few threads on this so please forgive me if this is a repost with a similar issue...

I know literally nothing about wiring and this is my first Mopar so I'm still learning the ropes, I will try describe best I can what the issue is. I also live in the UK so parts aren't readily available to me to buy and test within a few days, especially with current shipping costs!!! Hopefully nothing needs replacing and this is a simple fix...I can but hope lol

Basically everything on the car worked fine. I can't remember exactly when they decided to stop working but a few things I have done on the car recently are:

• Install a retro sound radio
• Installed a tach (had to drop the steering column & pull the dash out a little to neatly feed the tach wires behind it).
• Accidently pulled the plug seen in picture below whilst messing with my steering column and didn't know where it had come from (It was hanging in the engine bay near the brake booster, I later started the engine but heard a fuse blow and then found my tail lights had gone out. Replaced the fuse and eventually saw near the bottom of the car where all the brake lines were a fitting for it to go on. Fitted it back on and brake lights now work again.

Okay so currently all lights in the car work. Dash gauge, aux gauges, dome light, tail lights, brake lights, headlights and emergency hazard/flasher lights.

The only ones that do not work are the turn signals, the green arrow on the dash doesn't appear to be working either. When I turn the switch left or right there is nothing. No noise coming from the flasher unit, nothing.

When I hold the brake down, my brake lights work but when I select left on the turn signal the left brake light goes out and the right brake light stays on, when I put it back to the middle both brake lights appear, the same happens when I select right side...the right brake light goes out but the left stays on.

Few things I have tried...

• I tested the flasher unit on my dad's Lincoln, it works fine. So the unit is working.
• I checked all fuses, everything is working. Used a test light on them and all is good.
• I pulled the flasher unit and used the test light on the wires - there was no power going to the flasher unit.
• I pulled the steering wheel off and ran a live wire from the battery to the signal switch, this worked. It powered up the green arrows and the left or right lights came on at the rear. They didn't however flash, they were just constantly on. There was also no noise coming from the flasher unit.
• I used a test light again on the wires connecting to the flasher unit whilst running a live from the battery to the switch and yes this was indeed live now.

So this may sound like a silly question but I haven't a scooby doo what is going on, I take it there is an issue with the wire feeding the flasher unit because there doesn't appear to be any power to it only when I run a live from the battery to the signal switch directly? Any ideas on what I need to test next and where to go from here?

Sorry, car is a 72 Duster.

 

[67Dart273]

1...Moving the turn signal and a brake light going out is normal, because the turn signal switch then connects that lamp to the turn flasher
2...Wander over to MyMopar and wander around in there. Download a service manual, free, as well as the aftermarket wiring diagrams, which are DIFFERENT than the service manual, and NOT always as detailed, but are SOMETIMES easier to read and follow. In other words I use a combination of both
3...Bear in mind your car has TWO flasher units--one for turn, one for hazard. The hazard gets power at all times, the turn signals ONLY WHEN the key is "on." So when you checked for power, make sure the key is on.

Generally:
A....The fuse panel as THREE fuse power circuits. One buss is "hot" and supplies things like tail/ park lamps, brake lights, and hazard......The second buss is ONLY hot with the key in "accessory" or "run" and powers things like heater, radio, turn signals........The last fuse, by itself is an oddity........the instrument fuse at one end of the box. It GETS power from the headlight switch dash dimmer control, and FEEDS to the dash lamps

B....You can access the steering column connectors, one for ignition switch, the other for the turn signal switch, to check power for various circuits
C...ALWAYS check power such as "at a fuse" with the circuit powered (switch on) so that if possible it is under load. This is because a bad connection, either in a fuse, fuse clip, wire connection, switch, etc etc. Might "show" power with the circuit unpowered but may LOSE power trying to supply a load.
D...Downloads

MyMopar

Various wiring

Wiring and Electrical – MyMopar

The wiring for 72, this is AFTERMARKET, not factory diagrams. You will have to "unzip" them

https://www.mymopar.com/downloads/wiringdiagrams/1972Wiring.zip
Service manuals
Service Manuals – MyMopar

 

[DusterDeano]

Thank you, appreciate that.

Will take a look at them diagrams and yes I made sure the ignition was on and the turn signal engaged before testing for a live in the flasher unit, still no power.

 

[Mattax]

Another good resource are the Chrysler Master Tech booklets.
Turn signal operation is explained in 1965, #2.
1968 has one that explains wiring diagrams.

Master Technician Service Conference - Chrysler's Training for Mechanics
You may find that some pages linked at imperialclub don't work. Go to your address bar and change the url letter 'p' in page from small to capital letter (or the other way around)
or, knowing the year and month of the movie or booklet you want to look at, go to mymopar and download as pdf.

Main power circuits are arranged like this

I *think* hazard switch shares the brake light feed. This varied from year to year so worth checking.
It's often useful to turn the hazards on to determine if the problem with the turn signal is the same or different.


This is a colorized schematic of the turn signal operation. The hazzard has its own flasher unit but its not shown due to space.
Orange represents the switch contacts signalling left.
The contacts connect the power from the flasher unit to the wires on the left side.

When the brakes are applied at the same time as signalling a turn, power goes through the stop switch, through the hazard switch to the center contact of the turn switch and though the dark green right side stop lamp wire.

 

[DusterDeano]

Thank you Mattax!

 

[67Dart273]

You may find that some pages linked at imperialclub don't work. Go to your address bar and change the url letter 'p' in page from small to capital letter (or the other way around)
or, knowing the year and month of the movie or booklet you want to look at, go to mymopar and download as pdf.

WTF?? That Imperial Club thing expects you to download 1 page at a time?

 

[cudamark]

The red wire at the flasher should have power when the ignition switch is in the ON position. If it doesn't, you need to work back along the route to where it gets it's power. First stop for me would be the turn signal switch connector at the steering column. There should be juice going into the switch, and juice coming out on various wires depending on the position of the switch. Find the one that gets power only when the ignition switch is in the ON position. It should be the red wire coming out of the turn signal switch. That's the one that goes to the flasher. The emergency flasher and brake terminals will have power all the time.

 

[Mattax]

WTF?? That Imperial Club thing expects you to download 1 page at a time?

it was setup to be efficient in an era of dialup. Flipping through pages was more practical then for almost everyone. Bigger jpgs for those who want to print something. Still not a bad system. No idea why they keep changed domain names (com org info) and then have to redo all the links

 

[DusterDeano]

The red wire at the flasher should have power when the ignition switch is in the ON position. If it doesn't, you need to work back along the route to where it gets it's power. First stop for me would be the turn signal switch connector at the steering column. There should be juice going into the switch, and juice coming out on various wires depending on the position of the switch. Find the one that gets power only when the ignition switch is in the ON position. It should be the red wire coming out of the turn signal switch. That's the one that goes to the flasher. The emergency flasher and brake terminals will have power all the time.

Brilliant, will look into this thank you!!!

 

[French demon]

Accidently pulled the plug seen in picture below whilst messing with my steering column and didn't know where it had come from (It was hanging in the engine bay near the brake booster)
View attachment 1715931532

If I'm not wrong, this connector goes to the brake proportioning valve (just under the brake booster)
It's the brake warning light wire.

François

 

[DusterDeano]

If I'm not wrong, this connector goes to the brake proportioning valve (just under the brake booster)
It's the brake warning light wire.

View attachment 1715931918

François

Yes! This is where I think I accidently pulled it out, when I started the car later the fuse blew for the rear lights so I can only assume it was because this was unplugged. Thankfully after looking around I saw where it should fit and popped it back on.

 

[Mattax]

Unlikely.
Fuses open when too much current flows through them. That requires something like accidentally grounding the circuit to earth.

That wire specifically is made to complete circuit to earth. When hydraulic pressure in the front or rear circuits is low, the safety switch shuttles to contact earth. Current then flows through the Brakes lamp on the instrument panel.

 

[Mattax]

Unlikely.
Fuses open when too much current flows through them. That requires something like accidentally grounding the circuit to earth.

That wire specifically is made to complete circuit to earth. When hydraulic pressure in the front or rear circuits is low, the safety switch shuttles to contact earth. Current then flows through the Brakes lamp on the instrument panel.

Closing either the hand brake switch or the warning lamp switch completes the circuit.

 

[DusterDeano]

View attachment 1715931962
Closing either the hand brake switch or the warning lamp switch completes the circuit.

Gotcha! Thank you again!!

 

[Mattax]

Also noticed in the '72 FSM that the turn signal feed traces back to X12, also used for the radio. So for '72 the turn signal is fused.

Follow D1

which connects to B1

and B1 (white) to X12

X12 is fed at fuse C

So the path to the turn signal flasher unit apparently goes through the fuse box

 

[DusterDeano]

Also noticed in the '72 FSM that the turn signal feed traces back to X12, also used for the radio. So for '72 the turn signal is fused.

Follow D1
View attachment 1715932077 which connects to B1 View attachment 1715932078 and B1 (white) to X12View attachment 1715932080

X12 is fed at fuse C
View attachment 1715932076

So the path to the turn signal flasher unit apparently goes through the fuse box
View attachment 1715932082

This is great, thank you. Going to be taking a look at it tonight!

Here's the fuse box I have...

 

[Mattax]

This is great, thank you. Going to be taking a look at it tonight!

Here's the fuse box I have...

View attachment 1715932306

View attachment 1715932307

View attachment 1715932308

There's some of the problem!
Not only does it have the awful squeeze squeeze splice, but the several of the wires and colors don't match the diagram in the service manual.

Granted sometimes there are errors in the service manual diagrams but 'fraid to say this fuse box has been messed with.
Q2A is the power feed from the key switch accessory circuit.
Presumably the Q3 (12 gage red with stripe) feed from the main splice is on the second buss.
Its the other side of the fuses that seems messed up.

 

[DusterDeano]

Yeah some of the things I've found on this car has been shocking...

Should I remove that blue scotch lock (not sure if we call them the same things as you do in the US?) and solder them wires together? Would that be a better fix?

 

[Mattax]

Yeah some of the things I've found on this car has been shocking...

Should I remove that blue scotch lock (not sure if we call them the same things as you do in the US?) and solder them wires together? Would that be a better fix?

Not yet.
First I'd want to figure out why two more circuits were added to that fuse and what those circuits are.
Is this a standard US-Canada car imported ? Is there some UK related lighting requirements that might have forced a modification?

As far as tracing, might just go down the list of circuits and see what works and then remove the fuse.
For example does the radio work?
If so is wire X1 actually Blue with stripe or is it Red with striep and not connected where it should be...

 

[DusterDeano]

Not yet.
First I'd want to figure out why two more circuits were added to that fuse and what those circuits are.
Is this a standard US-Canada car imported ? Is there some UK related lighting requirements that might have forced a modification?

As far as tracing, might just go down the list of circuits and see what works and then remove the fuse.
For example does the radio work?
If so is wire X1 actually Blue with stripe or is it Red with striep and not connected where it should be...

Okay I'll take a look at this, it was imported by my dad from California. I'm the first owner in the UK and restored it over here. There was no radio with the car though at the time. I installed this afterwards and it works now but I haven't added anything to the fuse box.

We do have different laws here in the UK though regarding turn signals they have to be yellow. Although they are currently still red!

There aren't any modifications that came with the car when I first got it. I'm going to have to sit down and study the diagrams and just follow each wire and work out what is what.

 

[Mattax]

When a car was made without a radio the wiring would be the same. At least that's my opinion. I've not seen a seperate harness listing for radio delete cars.
I assume you didn't know about the connector plug when installing a radio so that check of the circuit won't work. Maybe you can see the original plug.
I just think its odd that we don't see a 18 gage wire with stripe X1, but we see a dark blue with stripe that's 14 ga ish; and on the hot buss fuses there's a violet wire with pink and a red with pink.

 

[Mattax]

Not seeing any updates to the service manual drawings here
The 1970 Hamtramck Registry "1972 Plymouth, Chrysler & Imperial TSBs" Page

But there is a TSB about taillight sockets getting bumped

 

[Mattax]

The other junction on that circuit is cavity W of the bulkhead connector.
See what wires colors are there and slo check the engine compartment diagram in the service manual. See what connects to it in the engine bay. Maybe power for reverse lights?

 

[DusterDeano]

The other junction on that circuit is cavity W of the bulkhead connector.
See what wires colors are there and slo check the engine compartment diagram in the service manual. See what connects to it in the engine bay. Maybe power for reverse lights?

Oh that's a point I don't have working reverse lights either, will look into that haha.

Cheers for all the advice lads! Appreciate it!

 

[Mattax]

If you want to use that extra fuse spot on the switched buss for radio and tach, proper clip terminals can be found used and new.'

Here's a new one on ebay US NEW DASH FUSE BOX HOLDING CLIPS FOR BUSS FUSE FORD/CHRYSLER 65-68-69-70-71-75, | eBay

I've also bought them from Evans
EvansWiring.com : Product Catalog
Made by AMP

As you guys used the same type of fuses maybe similar clips for other makes/models is more readily availbale on your side of the pond.