Blinker issue has me stumped...

[lostintexas]

I've been reading through old post and trying to diagnosis my turn indicator issue and I'm stumped. Here are the symptons:
1) Hazards work all four corners, blink perfect
2) Turn indicators will light bulds in the correct direction but will not flash
3) Hazards and brakes cause hazards to stop flashing

Here's what I've done so far:
Replaced all bulbs and connector housings (no change, well lights were a little brighter)
Replaced flasher relay (no change)
Swapped hazard relay and blinker relay (issues stayed with blinkers, so good relays)
Looked for civvy trailer wiring (nothing found, everything was in wire loom with no external trailer plugs found)
Checked fuse #14 with tester and tested good. (since bulbs light don't think this is the issue)

Here's my thinking:
The turn signal indicator switch in the steering column is working since it energizes the systems and in the correct direction.
The relays work since both flash the hazards.
All bulbs good since they flash and light with headlights.

What am I missing? The strange thing is the brakes causing the hazards to stop blinking. I think this may be the key but no clue how or why.

Any advise would be very appreciated.

 

[doghead]

Bad ground at the light socket(to body)

 

[Warthog]

Bad ground at the emergency brake?

 

[lostintexas]

Bad ground at the emergency brake?

Warthog,

I'm guessing you are referring to #3) Hazards and brakes cause hazards to stop flashing. I should have been more clear and this is the foot brake causing the lights to stay solid. I will recheck grounds ASAP and report back.

The only thing that has questioning this is the hazards work. Isn't the ground common for the blinkers and hazards or am I reading the wiring diagram wrong?

Thanks again guys will check tonight if I get off in time.

 

[Warthog]

There is a ground wire that attaches to the body that is near the emergency brake. There is usually a 6-legged connector that is with it.

It could be mounted different places. This ground can play havoc with the instrument cluster.

 

[Gunzy]

The brakes will override the hazard lights and that part is normal. What you are describing does sound to me like a bad T/S flasher. Was it replaced with the proper one? There are at least two different ones that look the same and plug in the same. %%@ is one of them.

 

[lostintexas]

The brakes will override the hazard lights and that part is normal. What you are describing does sound to me like a bad T/S flasher. Was it replaced with the proper one? There are at least two different ones that look the same and plug in the same. %%@ is one of them.

I ordered the flasher from LMC truck and it was a 552. I thought that there may be a difference and that is why I swapped the working one in the hazards with the new one. The hazards still worked and blinkers didn't so "assumed" it was good.

Warthog, thanks for the pic. I don't remember that wire being there but may have overlooked it. Will walk out and check.

Really appreciate everything!

 

[lostintexas]

There is a ground wire that attaches to the body that is near the emergency brake. There is usually a 6-legged connector that is with it.

It could be mounted different places. This ground can play havoc with the instrument cluster.


View attachment 455334

Hmmm, there wasn't a ground mounted on the ebrake. I'll dig deeper tonight and see if I can find it somewhere else. I'll also see if I can find it in the TM and see what it should go to on the other end and start there.

You guys rock!

Thank you!

 

[K9Vic]

Not sure why you ordered a 552 flasher from LMC when you can get them at Walmart or any parts store. Have you tried the solid state flashers, they are slight more but work better and needed when using a trailer with LED tail lights.

If the ground is bad or broken that may be the issue, it will be somewhere on that side. You may have to crawl under the dash and look up above the e-brake. I have seen them in different places.

 

[lostintexas]

Well, the ebrake ground is there and looks good.


The 552 was ordered from LMC when I was ordering lots of other parts and just easier to order than try sneak out from work.

I will pull and re-check the grounds at the lights again this weekend.

 

[Coffey1]

I may be wrong but hazards do stop blinking when brake applied have you checked all grounds

 

[Dr.Jay]

RTFM
TM 9-2320-289-20
wiring diagram f-13 service lights circuit. page 866

Check the diodes. There are two of them. Each is soldered in behind the fuse box, between the terminals for the flasher relays. ( they can be wrapped in gray tape, or bare)
These are zener diodes. If the diode is damaged from overloading caused by a bad ground (usually the front ground bolts at the core support), it is allowing current to flow in both directions. This causes current to bypass the flasher relay which can produce a constant on with no flash.
Warning If the diode is damaged, it will easily cause severe burns if you touch it while the circuit is energized !!

I have cut out a faulty diode when I have found one with a short, and soldered in a new diode which can be sourced at Radio Shack. It is a chore to perform the repair under the dash, and the fuse box must be dismounted.