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Turn Signal

The back turn signal on one side on my 2001 Ford Explorer Sport is not working. The lamp, socket and fuse haa been checked and are ok. What else is could be causing the problem.

Bad/cut wire, bad splice, that is a pretty simple circuit. It might be time to just start chasing and measuring the wires. Does the tail light work? How about when the emergency flashers are on? Does it flash?

What methods did you use to check the socket and the bulb?

Is that lamp on the hatch?  If so  the likely place is where the wires go between the body of the car and the hatch.

How did you check the lamp socket and fuse?  (Why does everyone start by checking fuses when they are seldom the cause of a problem?)

I swapped the socket and lamps from the working side in the back and it still doesn’t work. The parts from the side that didn’t work is working on the other side. I have never had any other problems with my vechile.

No the lamp is not on the hatch. You do have to open the hatch to be able to take off the cover to the lamps. I swapped everything but the wires from on side to the other. Working side still works.

Checked the flashers and it doesn’t work but the tail light does work. Brake light, signal and flasher isn’t working.

I’m not sure where the wires split, but you might be able to wiggle the signal lever and get it to work? If that’s the case, that would indicate a bad signal switch. If the emergency flashers work, that would indicate a problem in only the turn signal portion of the wiring, not the light wiring. You really need to get your hands on a wiring diagram and just trace it out with a highlighter and see where it breaks off.

Does this vehicle use the same lamp for the turn signal and the brake light? If it does, check to see if it lights when you step on the brake. If it does light then you’ve probably got a failed turn signal switch in the steering column

Start following the wires from the lamp assembly to the front of the vehicle. It may be as simple as with my '99 Mercury. I thought a bulb was bad, but that was not it. The next thing in the circuit is a plug and socket. Pulling it out and plugging it back in fixed the problem. I don’t know if it is a permanent fix. I did not have time that day to work on it any more and I have not taken the time to go back into it for a good inspection.

The brake light and the turn light are the same. Both not working. The tail light is above them and it works ok. Did have someone check the wires and found no breaks in the insulation and also no current. Where might I find this plug you are talking about?

One very common bulb (can’t remember the number) for brake/turn signal applications has two filaments. If neither is working, the most likely thing is that the ground wire from the socket to the chassis ground is broken or a connection at the socket or chassis has come loose or is corroded.

It sounds to me the problem is with the turn signal/hazard switch. Looking at some service data it shows they are combined together. If moving both the switches doesn’t help solve the trouble then you may have to replace that. The data shows the wire color to the left side may be blue-green/white. You could check to see if the wiring to the bulb is intact by measuring the resistance on that wire. Then remove the bulb to verify you are on the correct wire.

Tried everything above: brake and turn signal still do not work. Left blinker relay clicks fast, right blinker clicks slow…could it be the relay??

Did you measure the resistance of the wire connection I mentioned in my last post? If so, did removing the bulb in the left rear change the reading?

There is no relay in the circuit that I am aware of but there is a flasher unit.

Under the dash behind the steering wheel is a block with six relay/flasher units. When you engage the turn signal lever you can hear/feel the unit clicking. Pulled it out and put it back in no difference. Will get a meter and try to check the resistance in the wiring. Thanks!