Turn Signal/Electrical Problem

[CarZombie 25]

:helpsmilie:In early December 2010, my turn signals stopped working, I thought it might be a burned out bulb, but found all turn signals worked when the emergency flasher was engaged. I replaced the turn signal flasher and the passenger side or RH side flashed, but the driver side or LH turn signals still would not work. For some reason (I really don’t know why) I tried the running lights and found I did not have running lights on the LH side. They are fine on the RH side. I was befuddled by this and tried the turn signals again. I found if I had the running lights on, and then tried the turn signal on the LH side, I got a couple of flashes, but the turn signal flasher would burn out. I then replaced the turn signal switch, thinking there was a short in the turn signal switch. No dice, same problem. I then replaced the headlight switch, but still had the problem with the turn signal/running lights. In fact after I replaced the headlight switch, the emergency flasher burned out after only a couple of flashes. Obviously there is either a short or a ground issue, but the thought of trying to trace out all those wire almost leaves me in tears.

Has anyone had a similar problem and if so how did you fix it? I have a schematic, but for the life of me, and my Mustang, I am unable to figure out how I could use it to help me with this problem. Oh I should also note that after all this started, I lost the RH or passenger side rear brake light. No juice in the wire coming from the junction in the drive side of the trunk. Car is a 1970 Mustang Convertible.

I HATE ELECTRICAL PROBLEMS!!!

[danno 128]

Yes, you got a good mess going. One easy way to check things is to disconnect the harness of all wires going to the taillights. If you disconnect the rear lights harness and the front lights are ok, then you have found the problem is from the doors and back.

 

The connectors are just to the left of the ampmeter, you will need to remove the dash pad to find them. There are 3 connectors there, one goes to the drivers door light and speaker. Disconnect all of these connectors and see what happens. When you turn on the direction indicator, the front turn signal lights should turn on, they will probably not flash. Try the left, right, headlights, and even the brake lights. Verify that when you press the brake, turn on the turn signals and the front turn signal lights stay on.

 

This is a place to start. Let me know how it goes.

Danno

[vettist 10]

i also had a bunch of gremlins in my car when the headlightswitch broke,also check the connection of circuit box-eng bay connector there is a bolt that was loose on my car.

[rangerdoc 22]

Just to go off what danno said. Would it work just to unplug the tail light harness in the trunk at the connector that is usually behind the driver's rear wheel well? That way you don't have to remove the dash...well maybe not depending on the results you get but worth a shot.

[foothilltom 33]

Keep in mind...all of these circuits go through the turn signal switch (located below your steering wheel). There are about 9 wires coming from here that run to every one of the subsystems you've described.

 

If it were me, I'd get out my test light and test for 12V on each of the various wires coming down the steering column (to the plastic connector under the column) for each system you suspect.

 

For example, engage the left turn signal and measure for 12V on that wire (i believe it was orange with green stripe if memory serves). Use your wiring diagram to make sense of them. If you get no 12V on that wire, it's a good bet your turn signal switch is DOA.

 

I wound up having to replace this turn signal switch on both my Mustangs. It can drive you crazy chasing down the possibilities, but just isolate one circuit at a time and you'll work it out.

 

My $.02,

Tom

Edited January 12, 2011 by foothilltom

[Redneck 10]

Car zombie. Did you figure out your problem? Having a similar problem

[Redneck 10]

Car zombie. Did you figure out your problem? Having a similar problem

[CarZombie 25]

Redneck,

 

First good luck with your problem as electrical is so weird. In my case, I was about to take the car into a shop and pay to have someone else check the wiring. Before I did that, I wanted to make sure I had covered the basics, so I pulled the fuses and rechecked them, one last time. When I did that, I decided to really clean the fuse terminals. I put the fuses back in and both my turn signal and emergency flasher problems were solved. This was a couple of years ago, so I am not a 100% on this, but I think the brake light problems were a dirty terminal and/or a bad bulb. I have had no more problems with the turn signals or flashers. As a side note, shortly after the turn signal problems, I could not get my AC/heater blower to run on high. I pulled the wire off the connector on the blower motor and cleaned the connector and the plug, and guess what, problem solved. With electrical start with the simple stuff, good ground, clean connections, and work towards the more complex. Let me know what happens.