Running lights but no brake or turn signal

On one of my vehicles the trailer fuses are located in a fuse box back in the rear of the vehicle.

Should be under the hood fuse block. There are several that should have "TLR in discription. LL tlr, RR TLR

Get an repair manual sometimes the relays are not located in the fuse box. It will really help you to understand how your tv is setup. You might be able to find one online in a PDF format

enblethen wrote:
Did you find the trailer connector fuses?
There should be two for each function.
Did you locate any relays in the fuse box for the trailer connector functions? If you have try swapping them with the trailer tailight one. It could have ate the relays.

Thanks. Where exactly would I find the trailer connector fuses? I have checked all my fuses and they all seem to be working. I'm having some difficulty determining exactly which ones control which functions. I've checked the wiring and there doesn't seem to be any visible problems.

I'm ready to pull my hair on this one.

Did you find the trailer connector fuses?
There should be two for each function.
Did you locate any relays in the fuse box for the trailer connector functions? If you have try swapping them with the trailer tailight one. It could have ate the relays.

Dr Quick wrote:
Try this with your trailer battery connected. When you look at the connector from the trailer and the "index" it up, the 11 o'clock position is the hot or 12 volt to your trailer battery. Use a small jumper wire from 11 to 1 and the running lights will come on and also the tail lights. Go to the 9 or 3 position and the brake/turn lights should come on one at a time. It lights come on, the problem is in the truck, if not, the problem is in the trailer wiring. If tail lights or turn/stop lights do not work, it could be a bad ground to the rear lights.

Two other vehicles have been hooked up to it and the trailer lights have worked properly. The only thing left to check is the fuses. I have checked them before.

Try this with your trailer battery connected. When you look at the connector from the trailer and the "index" it up, the 11 o'clock position is the hot or 12 volt to your trailer battery. Use a small jumper wire from 11 to 1 and the running lights will come on and also the tail lights. Go to the 9 or 3 position and the brake/turn lights should come on one at a time. It lights come on, the problem is in the truck, if not, the problem is in the trailer wiring. If tail lights or turn/stop lights do not work, it could be a bad ground to the rear lights.

Fuses under the hood!

Check your Taho owner's manual and check your fuses. Our Chevy truck has this issue and that is typically the fix. The turn signals etc. run on different fuses which is odd, but that's how they built them.
Our business partner has a Ford F-150 and it has the same problem. He carries several spare fuses because of it.

Most Fords have the trailer wiring fuses and relays under the hood. I do not know about Chevy. But I would look for some fuses under the hood and check them.