View Full Version : Turn indicator not working

12-25-2014, 01:46 AM
Hi everyone! I'm new here and new to the Dodge Coronet. I just picked up a 72 with a rebuilt 318 in really good condition except for a few electrical problems. The worst of which is that the indicators will not work. The emergency flashers work fine and I can hear the relay clicking. I pulled off the steering wheel to take a look at the indicator switch and it appears that the switch has been replaced as the plastic and connections look brand new. I took a peak under the steering column and the wires come out and connect to an 8 or 9 pin junction that then distributes them out further. That is where my investigation ended for now. A lot of the wires looked monkeyed with under the dash so it's almost impossible to follow the wiring diagram I have. Does anyone know how the wires that come out of the switch are supposed to be routed? Looking at this wiring harness makes me want to get a new remanufactured one and just spend a week rewiring to stock. I think there is a white, red yellow, yellow green, green, and green yellow coming off of the switch under the steering wheel. Any hints can help, thank you! God I hate electrical problems....:(

12-26-2014, 06:10 AM
In the mean time I'm going to start working on bypassing the ammeter and maybe in the process find my blinker issues. If I do I'll post um here.

12-26-2014, 10:40 AM
This might be your best bet to find out which wires go where..


12-28-2014, 10:30 PM
Are you saying the indicators in the dash are not working, or the front and rear bulbs are not blinking, or neither? There is a plug under the drivers kick panel that sometimes comes completely or partially apart. It connects the wires coming from the steering column to the rear light wiring harness. Just follow the wires from the column until you find it.

12-29-2014, 03:28 PM
I'll check on that kick panel. As of right now, no lights are blinking including the dash lights. When I hit the hazards however they all blink.

01-01-2015, 12:54 AM
If the rear lights work with the flashers, it won't be a problem with that connector, as those wires provide power for all rear lights. You might have a problem with the flasher being bad or missing. It is a metal plug in device, either rectangular or cylindrical. On my '68 it is behind the dash, near the steering column, but at some time Mopar started putting them on the fuse block. Find out where yours is located and remove it. It will have 2 prongs for power. Hook it up to 12 volts (polarity doesn't matter) and feel and listen to see if it clicks. I am referring to that noise you hear when you turn the turn signal on. If you can't hear it or feel it clicking, it is bad, so replace it. This flasher is separate from the emergency flasher device, so make sure you are checking the correct one. If the flasher clicks when you test it, but not when it is plugged in, you must then have a wiring problem.

01-01-2015, 11:26 PM
The wiring diagram indicates 3 wires going to the emergency flasher (it still has only 2 prongs) and 2 wires going to the turn signal flasher. Here is a simplified wiring diagram from my '68 FSM.

01-02-2015, 05:45 PM
Excellent information! Thank you mike1968rt! This will help a lot for checking continuity between the switch and the lights. I wrapped the car up for the winter yesterday as we are about to get a bunch of rain here so I may not get back to this for a bit. But before I did I took a bunch of pictures of what I'm looking at under the steering wheel.

This is the relay that clicks when the emergency flashers are engaged. It has two prongs but three wires like you had stated. Pink and black in this case.

I'm not sure what this is. It seems like it may be a relay...?

A couple of unhooked plugs. I'm wondering if the one of the left is where the indicator relay should be? Does the plug pattern look familiar to anyone? It two prongs but four wires coming out. The wires are colored black and black with a yellow stripe.
Here is what Rock Auto lists as the "flasher relay" the plug orientation looks very similar to that black plug in my picture...

Another mystery plug. One tan wire into a three prong female plug.

The fuse box looks to be missing the horn relay(center 3 prong plug) and the right plug that is empty is labeled "Buzzer" I think. Also are the "ACC" and "BATT" plugs just for testing purposes or are there supposed to be wires going there?

01-02-2015, 10:41 PM
Starting from the top, the metal cylinder is a delay for the ignition key light. After the doors were closed this device kept the ignition key light on for about 20 - 30 seconds. The plug with 2 holes is for a dash speaker. Premium sound systems had two 6 x 9 speakers in the rear package tray and two small round speakers in the left and right side of the dash, pointed toward the windshield. I don't know what that other wire is for, but most likely some sort of accessory. The plug with the tan wire is a tap off of the roof light. Accessories such as the radio dial light and the ash tray light were plugged into it. Hence when you adjusted the brightness of the dash lights, the radio dial light and ash tray light dimmed too. The spade plugs on the fuse box are also there for accessories. The acc tap provides power only when the key is turned on, while the batt tap provides constant power. Over the years I have connected stuff like 8 tracks, cassettes and the like to those taps.

01-02-2015, 10:44 PM
I forgot, if you didnt find another metal device I would guess you are missing the turn signal flasher. Here's hoping that that is so, and as soon as you get one and plug it in, all your problems will be solved!

01-02-2015, 10:54 PM
I am pretty sure the "buzzer" on the fuse box is for noisemaker that indicated you had left the key in the ignition when you opened the door.

01-02-2015, 11:08 PM
As near as I can tell, the flasher is not mounted on the fuse box.

01-02-2015, 11:31 PM
I just had another thought. if you find the plug for the turn signal flasher and you put a jumper wire between the 2 holes in the plug all lights should turn on , but not blink. Use a pretty good gage (diameter) wire, and don't leave it plugged in too long. If your so inclined an even better way is to use a 10 amp fuse with jumpers attached to each end, and then if you have a short in the wiring, the fuse will blow instead of smoking any wires (I hate that smell for a few different reasons).

01-02-2015, 11:54 PM
Just to clarify, when the jumper is in place, on the right or left lamps will be lit (the key must be on and the turn signal lever turned on one way or the other). So if you have the turn signal lever in the left turn position, the left hand lights will be on but won't blink.

01-03-2015, 12:04 AM
For some reason the 72 wiring diagram only shows the color of one wire leading to it, but the 73 shows a red and a black wire, as does my 68 FSM, so I'm pretty sure that is what you need to find.

01-03-2015, 05:02 PM
Thank you thank you! This is all excellent information. I'll definitely use a fuse as I don't want to cause any more issues. I'm not seeing any other plugs up in there and I don't think it has the rear speaker package. As far as I can tell it's just one speaker in the center and I know where that plug is(the original radio is out but I have it to put back in some day). I'll look more closely for the possibility of speakers having been in there at some point. You'll see in a few of the pictures there is a mysterious yellow crimp cap in the background with 3 wires going into it and spliced together very terribly. I wonder if this is where the plug used to be.

01-03-2015, 08:11 PM
Are two of the wires colored black and red? If so that's probably your junction. Some accessory wires were included in all the harnesses, and if that particular accessory was not ordered on that car, the wires just sat there, unconnected. If you can't located that plug for the flasher, somebody did some jury rigging. The most likely location would be under the instrument panel, behind the lower part of the dash, between the steering column and the radio. Iam not trying to insult you, but sometimes the most likely cause of a problem is overlooked. Have you checked the turn signal fuse. Take it out and check it for continuity (you'll need a multimeter) , or take it out and just replace it. Sometimes they can look good to the eye, but actually be bad.

01-03-2015, 08:33 PM
I just did some continuity checks on my dash harness (which is out of the car). The black wire shows continuity to a black wire that is one of several that plug into the headlight switch. The red red wire shows continuity with the red wire that is part of the connector at the bottom of the steering column. This is the connector that goes through the steering column and is attached to the turn signal cam switch. So the black wire should show 12 volts present any time your key is turned on. The voltage will not flow through the flasher until the turn signal lever is in the left or right turn positions. Now granted I am working on a 68 with rally gauges, but I would bet after looking at your 72 wiring diagram and my 68 there should be no difference.

01-03-2015, 10:32 PM
Anything is possible when youv'e had someone messing with wiring, but it is not logical that the wires that are sloppily put together to be the wires that would have gone to the turn signal flasher. because twisting them together would be the equivalent of running a jumper at the flasher plug. You would then have steady lights when the key was on and the turn signal lever activated.

01-03-2015, 10:40 PM
Anything is possible when youv'e had someone messing with wiring, but it is not logical that the wires that are sloppily put together to be the wires that would have gone to the turn signal flasher. because twisting them together would be the equivalent of running a jumper at the flasher plug. You would then have steady lights when the key was on and the turn signal lever activated.I would try following the red wire from the steering column connector away from the steering wheel. I know sometimes those wires are wrapped in a plastic tape, but it's worth a try

01-04-2015, 01:59 AM
Will do. I did check the fuse with a multimeter just to make sure and it shows no resistance. I also checked continuity between the connections on the cam and found a lot of them to be connected including connected to the emergency flasher switch. I'll get in there with a multimeter soon if the weather gets a bit better here. I have no garage unfortunately.

05-05-2015, 11:43 AM
Found the wires! Turns out those wires going into the crimp cap were the ticket! There was just a black wire(the ground) that had fallen out so I wasn't getting continuity when the indicator was turned on. Now my problem is that I can't find a blinker relay anywhere. Can I find any 12v indicator relay and use that?

05-24-2015, 06:03 AM
I've got it all fixed and working great now. To anyone needing this information. In my case there was a lot of confusion because there were 4 wires going into a crimp cap, two orange, one red with a white stripe, and one black. With a multimeter I quickly discovered that the two orange wires were always grounded and not a part of the indicator circuit. The red wire with the white stripe was a constant 12v with the key ON and the black wire was only connected to ground if the indicator was activated in either direction. All I needed was a 12v relay and I attached the red white stripe wire to the supply end and the black wire to the load end and all fixed!
The relay I used was the LittleFuse 536/552 style.

05-24-2015, 05:56 PM
Thanks for the info!