Turn signals only work sometimes…

[KansasIDI]

So on my 91 F-Superduty service truck, the turn signals don’t always work. The indicators on the dash work when the actual turn signals work, but sometimes neither work. They always click like they are supposed to. I replaced the round flasher on the fuse panel, no difference…

What could it be?

 

[DaveBen]

When you say they don't work, are you saying that NONE of the turn signal light work? Are the front signals and rear signals working together (at the same time)? Is there a light that does NOT work?

 

[KansasIDI]

When you say they don't work, are you saying that NONE of the turn signal light work? Are the front signals and rear signals working together (at the same time)? Is there a light that does NOT work?

No. Either everything works. Or everything doesn’t. Not just some of the stuff. All works or none works.

 

[Kizer]

No. Either everything works. Or everything doesn’t. Not just some of the stuff. All works or none works.

I'd bet that your problem is close to the light switch.
Switch (itself), loose connection or the connector (female plug) went **** up.

 

[Kizer]

The **** = t it s
F'n robot!

 

[THSIM9]

LED bulbs or original? I had to replace the flasher with a different model when I went to LED’s.

 

[Rdnck84_03]

May not be your issue but try turning the key slightly forward or backwards, my 82 the turn signals sometimes won't work and I can turn the ignition switch slightly back and get them to work.

James

 

[bumblebeer]

Maybe it's part of the safety or navigation feature? Do they only not work when trying to make an illegal u-turn or going the wrong way on a one way?

But seriously seems like a good excuse to invest in a power probe. I'd start at the ignition or headlight switch as previously suggested. Also would be worth doing the headlight relay mod since you'll already be in the electrical anyway.

 

[franklin2]

Headlight switch has nothing to so with the turnsignals. Totally different circuit, different bulbs, different wires.

1st thing I would do is take the hazard switch on the column, and pull it up and down rapidly about 20 times. Push it back down and then see if they start working.

 

[XOLATEM]

take the hazard switch on the column, and pull it up and down rapidly about 20 times. Push it back down and then see if they start working.

That reminds me of Tae Quon Do class...they had us rub our hands together vigorously 33 times...then do something with them....

I never thought of this idea...but next time I have a problem like this I will try it first...

Then I will take my Power Probe and see if the cab is grounded to the frame...and then check the turn signal circuit going into the ign. switch and then the actual turn signal switch will get the scrutiny...

If you go to the fuse panel and find the turn signal fuse and check for power and ground it would probably help...

Good luck on it...

Oh, yeah...this is the service truck...

well...the work body was put on and the rear lights were adapted...

I would check in the back just to see how everything looks...

 

[KansasIDI]

Maybe it's part of the safety or navigation feature? Do they only not work when trying to make an illegal u-turn or going the wrong way on a one way?

But seriously seems like a good excuse to invest in a power probe. I'd start at the ignition or headlight switch as previously suggested. Also would be worth doing the headlight relay mod since you'll already be in the electrical anyway.

I have a power probe. And I bought a headlight harness from Bronco Graveyard that has relays. But my truck is Canadian. The harness is different because it has daytime running lights... So I still need to look into that...

 

[tbowker]

Then I will take my Power Probe and see if the cab is grounded to the frame...and then check the turn signal circuit going into the ign. switch and then the actual turn signal switch will get the scrutiny...

I've been accused of being an electrician a few times and I'll second this statement.

I have a power probe.

You guys with these power probes... now I have one in my Amazon wish list. If my wife wonders why I'm buying more tools I'm blaming you guys.

 

[KansasIDI]

You guys with these power probes... now I have one in my Amazon wish list. If my wife wonders why I'm buying more tools I'm blaming you guys.

Same. We will use each other as excuses to make tool purchases justifiable.

 

[Rdnck84_03]

Same. We will use each other as excuses to make tool purchases justifiable.

I don't bother making it justifiable. When it comes to tools, if I don't have it I will buy it if it's something I think will be useful. My wife doesn't like my way of thinking but normally doesn't complain too much.

I think she knows that if she doesn't let me buy tools, I won't let her buy all her crafty beadwork crap so it all works out.

James

 

[Old Goat]

Happy Wife, Happy Life.

Tools? yeah it`s uz guys fault I had to buy the Noco GBX155 4250A Battery jump pack last Sunday.


Goat