Turn Signal Switch or Relay Failing?

Hi All-

My 2002 Ford Ranger is finally starting to show its age in a few ways, and one that just cropped up two days ago is that my turn signal switch is acting funky. Sometimes, it won't turn the blinker on at all, but a other times, the lights will blink a few times and then stop, or blink about a dozen times and then stop, or it works relatively normally until I make my turn and it clicks off like normal.

All of this is happening with the turn signal lever in the appropriate position to be causing the lights to blink--it is not moving out of position, the lights just stop blinking.

Does this sound like a turn signal switch problem, or a relay problem? Normally, I'd just jump right in and replace the switch, but with the switch being $90 on Rock Auto for the Motorcraft option and the relay being around $10, I'd certainly prefer not to replace the switch if I don't have to.

I'm electrically illiterate, so if this comes across as a stupid question, it's because I'm stupid with electrical systems. I can rebuild the crap out of an engine or do good body work, but I'll throw a car away if there are electrical gremlins in it.

Thanks all.

Oh, and when the lights quit blinking, the lights will always be remain off-- it never makes them stick on (lit).

It is possible it is the relay, usually something like that involves corrosion on the contacts of the relay if it is the relay. It could also be caused by some corrosion elseware, even the ground wire going to the dash might need some cleaning.

The symptoms do seem more like a switch problem though. They are not the easiest to change. So I would check for a ground problem and pull the relay to see if it has corrosion on it first. Clean the battery connections too. It doesn't sound like corroded taillight or headlamp sockets, the flashing would be fast for that if there was no connection. A rusted groundwire to the taillight on an older ford Truck I had caused something like that, the connector corroded right off for the ground, when it touched, the lights worked, when not, there was no lights at all in that light, no blinker at all. That was an 88 though, there are differences in the system there.

I have a 2000 explorer presently, I usually have two or three brands of vehicles I work on.

a reply to: rickymouse

Thanks...I will check the grounds, but this is the only thing not working properly, whereas every other light and switch and electrical device on the truck is working perfectly, so I don't think that a faulty ground is the issue, but you never know.

Luckily, changing out the switch isn't very hard at all in this truck, so I'm not worried about the labor part on my end--it's literally three screws, two Torx screws, removing two wiring connectors and reversing that order. But, of course, all things that seem simple to me never end up being that way, as I always find something else to work on.

What are your thoughts on going with a non-Motorcraft switch (if you would be so kind)? I know from experience that going cheap with electrical items can cause future issues, so I'm hesitant, but there are some cheaper options that are all about 50% less than the Motorcraft switch. If this didn't also control the emergency flashers, the bright lights, and the intermittent wipers, I might not be so concerned (all of which are working fine, it's just the turn signals).

Motorcraft switch ($87.79)

Standard Motor Products switch ($40.79)

originally posted by: SlapMonkey
a reply to: rickymouse

Thanks...I will check the grounds, but this is the only thing not working properly, whereas every other light and switch and electrical device on the truck is working perfectly, so I don't think that a faulty ground is the issue, but you never know.

Luckily, changing out the switch isn't very hard at all in this truck, so I'm not worried about the labor part on my end--it's literally three screws, two Torx screws, removing two wiring connectors and reversing that order. But, of course, all things that seem simple to me never end up being that way, as I always find something else to work on.

What are your thoughts on going with a non-Motorcraft switch (if you would be so kind)? I know from experience that going cheap with electrical items can cause future issues, so I'm hesitant, but there are some cheaper options that are all about 50% less than the Motorcraft switch. If this didn't also control the emergency flashers, the bright lights, and the intermittent wipers, I might not be so concerned (all of which are working fine, it's just the turn signals).

Motorcraft switch ($87.79)

Standard Motor Products switch ($40.79)

A lot of stuff has grounds coming from the wiring harness, some things utilize the body ground though. If the switch is a little corrroded internally or worn, upping the power coming to it can help, there is electronics in that system. Check to make sure the prongs on the blinker relay are not oxidized. Just pulling it out and pushing it back in will often make the connection good again. I always check connections first, lots of time the computer says something is faulty and all it takes is cleaning the connections and it works fine. changing the part will fix it, but that is because you are getting rid of corrosion. It is way cheaper to check the connection. The only way that the switch contacts in the steering column get corroded is if you dumped coffee or Soda on the steering column when you drove sometimes. I had that happen once, I had a problem with a blinker when I dumped mountain Dew on my steering column. No parts needed, just a fuse.

The relay connections can get corroded. I would try that first.

I would go with the Standard switch, they make a decent product. The age of the vehicle means the cheaper the better. Try Amazon, sometimes they have stuff like that for older vehicles cheap.

a reply to: SlapMonkey

Try checking the hazard relay . Its really hard to know without knowing the schematics but some hazard relays tie into the larger scheme of the electrical ...

a reply to: rickymouse

Sounds good--I'll look into the relay as well.

Thanks for the recommendation on the part, too, if I need it.

a reply to: the2ofusr1

That's a good point, but I'd be willing to bet (without looking at a wiring diagram) that the relays are the same, considering that the hazard switch is located at the housing of the blinker switch and is part of the assembly. In either event, I haven't tried the hazard switch yet, so I'll give that a try at lunch and see if it does the same thing as the blinkers. I don't what that will prove, but it will remove that question from the equation, anyhow.

a reply to: SlapMonkey

Sounds like a wire broke in the turn signal stalk assembly, and is making connection intermittantly, i have seen it many times. The wires are really thin, and constantly moving up and down wear them out and they break, i would start there.

a reply to: SlapMonkey

On audis, if the turn signals wack out, its usually the hazard switch, cuz the turn signal switch goes thru the hazard switch, if you give me ur vin i can get u a wiring diagram.

a reply to: SlapMonkey

If its an intermittent problem its probably the flasher. Usually they are under the dash, if your vehicle has two (right and left signal) you can try switching them to see if the problem moves to the other signal.
I'm saying this because I know you already tried changing the bulb.

a reply to: neomaximus10

Yeah, I'll give everything inside a good inspection, plus I'll probably let my OCD takeover and clean the hell out of it since the "clam shell" covering the steering column probably hasn't been removed in its 15 years of existence. Might as well remove the gauge bezel and replace that burned out light bulb that illuminates one of the gauges, too.

This is why, when I had a '66 Mustang, that it ended up in pieces that I had to rush to put back together when I wanted to sell it

originally posted by: intrptr
a reply to: SlapMonkey

If its an intermittent problem its probably the flasher. Usually they are under the dash, if your vehicle has two (right and left signal) you can try switching them to see if the problem moves to the other signal.
I'm saying this because I know you already tried changing the bulb.

Tread lightly on your assumptions

I haven't needed to replace any bulbs because none are out.

Here is the diagram of the relay box under my dash, which seems to show that the turn signals and the emergency flashers share the same relay. If I can get to it without and specialty tools today at lunch, I'll pull the relay out, check the connections for corrosion, and put it back in and see if it makes any difference. Of course, if it's easy enough, I may just run to an auto parts store, buy that relatively cheap item, and swap them out to see if that fixes the problem.



Thanks for the reply.

So, to simplify things in my electrical-ignorant brain, the relay causes the flashing, and the switch is just what activates the relay?

a reply to: SlapMonkey

Lots of in depth # for a signal switch. If you are worried about the flasher turn your hazards on. Do they blink?
Yes?
Replace switch.
No?
Replace flasher.

Is the problem the same on both sides? If it is, I suspect the relay. If it is only on one side suspect the switch or wiring.

a reply to: SlapMonkey

The reason I had mentioned the hazard relay was because that is where I had traced my problem down . It didn't make sense at the time but I was desperate and made the change and it fixed the problem .Mine was on a VW but some electrical plans lend to other models . Even borrowing a flasher from a friends ride might tell you strait up weather to purchase the flasher as some of them can range up there in the $$$

a reply to: SlapMonkey

Here is the diagram of the relay box under my dash, which seems to show that the turn signals and the emergency flashers share the same relay.

Bummer, they used to be separate so you could swap them to check. They don't even call them flashers anymore...
Anyway, from your initial assessment of the symptoms( signal starts working and then stops), my money is on the 'relay'.

Further:

I haven't needed to replace any bulbs because none are out.

The turn signals in the front and back are controlled by the same relay. If they both go out after a few blinks, its not the bulbs.

originally posted by: TinySickTears
a reply to: SlapMonkey

Lots of in depth # for a signal switch. If you are worried about the flasher turn your hazards on. Do they blink?
Yes?
Replace switch.
No?
Replace flasher.

Yes, this is basically what I did over the weekend, and the hazards are working perfectly and without fail.

I ordered the switch Saturday, so we'll see when it gets here. To all who responded to my issue, I appreciate it. I'll get back on here and let you all know if the switch fixed it, even if the update falls on deaf ears.

Thanks!

a reply to: SlapMonkey

good.
you dont need wiring diagrams and # for this problem.
you will be good to go once you get i put in. these multi function switches can do all sorts of goofy stuff. recently my fog lights would come on or some # unless i had the switch down in the left turn position.
something stupid like that but anyway it is the switch but its expensive so i pulled the fuse for the fog lights. had the car a few years and ever once used them.

a reply to: TinySickTears

Man, if I needed a wiring diagram to figure this out, I'd be taking it in and letting someone else do it

Supposedly the switch will be here today, and it looks like about a 20-min job, so hopefully I have good results.

Thanks again.

a reply to: SlapMonkey

good deal.
gonna trip you out how easy it is