No rear turn signals or brake lights

[mweiman]

I haven't looked at it yet but my brother's 07 mega cab has no rear turn signals or brake lights except the third brake light on the cab. He said he replaced both bulbs, it is also giving the lamp out message on the dash. I am not sure about the trailer plug. If it is tipm issue what can be done to test it if anything? I will check the taillight assemblies out good, but I don't think both of them would go bad at once. Any other ideas or thoughts would be appreciated.
Thanks,
Matt

 

[mweiman]

Are the trailer and truck tail lights on separate circuits? He pulls a camper so maybe it caused an over current condition. Does anyone know what years had the tsb to up the amperage on the circuits?
Thanks,
Matt

 

[mfurrh55]

Check the fuses?

 

[mweiman]

I didn't think there were any fuses, isn't everything internal to the tipm on the turn signal circuit?

 

[mfurrh55]

Look under the hood on the drivers side and you will see the big black housing that contains the fuses,Monte

 

[mwilson]

Office chair suggestion...if the fuses check out ok...

See if the trailer plug has power for the brake lights and turn signals, if not I would suspect either the TIPM or multi-function switch. The third brake light feed does not go through the multi-function switch (I think)....at least on old school stuff it does not. Third brake light works the same way as the brake lights on a semi-trailer, not tied to the turn signal switch.

Mike.

 

[JerryNelson]

I had my rear back up light go out and it ended up being the tail light circuit strip. $12.95 at Genos. good as new

 

[mweiman]

Looked at the truck tonight. All the fuses are ok, and there are no taillight strips on an 07. There is power to the trailer turn signals also. I found the wire going to the left rear turn and powered it and the left turn/brake lit up. Thinking it has to be internal to the TIPM.

 

[Motorhead]

DO the signals and brake lights work through the trailer light plug? All of those lights are controlled by the TIPM. The truck lights and trailer light plug circuits are on different parts of the TIPM. If the TIPM has tripped then you need to find the cause and have it reset.

 

[mweiman]

Dealership in town and also in neighboring town said they can't be reset.
Matt

 

[Motorhead]

That's bull crap too. Try another dealer.

 

[Prairie Dog]

Unfortunately most dealers don't understand what the TIPM is or how to reset it.

 

[scootergmc]

Another office chair diagnosis here:

I fixed a co-workers tail light issues on her '06. It was similarly weird and presented itself when she plugged in her 5th wheel. Found a thread here that said the wiring loom that runs next to the parking brake rubs and eventually causes a short to the tail lights. Looked down there and found the exposed wiring. I taped it up, moved it away from the brake and everything works as new.

I don't know if it helps, but it's another easy place to look.

 

[Motorhead]

Another office chair diagnosis here:

I fixed a co-workers tail light issues on her '06. It was similarly weird and presented itself when she plugged in her 5th wheel. Found a thread here that said the wiring loom that runs next to the parking brake rubs and eventually causes a short to the tail lights. Looked down there and found the exposed wiring. I taped it up, moved it away from the brake and everything works as new. I don't know if it helps, but it's another easy place to look.

Darn good observation for all of us with these trucks. A good place for us to check to prevent issues later. I am going to check mine (2007, 5.9) today. THANKS!!
Just for that....You get a Smiley Face!

 

[mweiman]

Scooter was the wiring rubbed on the parking brake cable or was it something in the cab?

 

[scootergmc]

Scooter was the wiring rubbed on the parking brake cable or was it something in the cab?

Sorry I haven't responded sooner.

The wiring was rubbing the metal of the parking brake foot pedal in the cab... The wiring runs next to it. Over time it just rubbed through the wiring. Poke around these wires:

 

[mweiman]

I will have to start checking the wiring around the parking brake pedal. He replaced the tipm and has brake lights again. Thanks for all the replies.
Matt

 

[Motorhead]

I will have to start checking the wiring around the parking brake pedal. He replaced the tipm and has brake lights again. Thanks for all the replies.
Matt

Just out of curiosity..... What did the TIPM replacement cost? Most important.... Did they find out WHAT caused the TIPM to trip or fail??

 

[scootergmc]

Just to follow up, I think my memory is telling me that it wasn't actually rubbing on the brake itself, just some of that underdash bracketry shown in the pic. Regardless, glad to hear it was resolved.