I recently pulled the bed on my 93 pickup to change the shock mounts. After bolting the bed down, the turn signal lights both flash when i turn the signals either direction on. Even the brake lights flash untill i press the brakes, then they all stay on. When I press the brakes, both blinker indicators illuminate. Checked the bulbs and sockets. checked grounds in the back. I can unplug both tail lights and still flash the same. I cant find a good diagram for the rear lights. Ive looked at both the FSM and this website for hours. Any help is appreciated.

 

Have you checked for pinched wires

I am guessing all was good to you pulled the bed off

Welcome to Yota Tech!!

 

Finally isolated the wires. between cab and bed somewhere.

 

bringing this back!!

i bouhgt a truck and it has this problem. My turn signals are fine, but when i press the brake everything flashes. If i am not using the turn signals and hit the brakes, the brake lights flash like crazy.

The wires look fine but i am going to look more careful this time. Mine doesn't have the trailer harness either, which seems to be the problem most of the time.

 

Explain Flash like Crazy ??

Did you mean blink like a flasher in the Circuit ??

Flash on and off in a Random pattern ??

Sounds like a poor connection

Corroded connections

broken wires

 

flash like crazy
- right turn signal on and it blinks fine. hit my brake and then both of my turn signals flash and the brake lights in a random pattern.
(can't recall if my reverse lights light up too)

- not using turn signals, hit brakes and the brake lights flash erraticly.


i bought a can of that "electrical connector" cleaner and i sanded some rust off of a few contacts. most were good.That didn't seem to make a difference because the issue was still there.

The tailights are rusty on the back side, and the lens & seals are damaged any ways so i just bought new tail lights. I bought a pair of tail lights from some one over seas, on ebay, so i have to wait 3 to 4 weeks before they arrive.

i will have a 3.8 powered truck hopefully before the taillights even arrive.

 

I disconnected the pigtail in the cab, and tested all the wires. From behind the dash leading to the pigtail. Everything seems good except a yellow/blue wire. It is always hot. I was using a test light and when the bulb was always lightly lit. And when I touched the light to it, the low fuel light would go on . . . Wired.

 

Maybe that yellow/blue wire is supposed to stay hot.
Got schematic?
Got multi-meter?
A problem well-stated is a problem almost solved. If you told us what truck model year you have, someone could share a schematic with you so you can more effectively troubleshoot.

 

This happened to me. One of my bulbs melted and the brake filiment melted and touched running so when I hit my brakes my running lights and front turn signals lit up. Check the bulb filiments

 

Wait, edit. I wired my running lights to blink. That's why the blinkers lit up too.

 

It probably should always be hot but it seems weird how it lights up the low fuel light every time I touch it.
I do have a Haynes manual and the schematic seems hard to read. It only shows a blue/yellow wire briefly at one spot. I do have a multimeter but haven't been working on the truck. I have been traveling for work a lot so when I'm home I cleaning and cooking . . . Catching up.

I bought new tail lights off of eBay they shipped from Thailand. Not directly the same plugs but clean.