Can't get brake lights or hazards to work.

All other lights work.
Bulbs are all good and wiring looks to be ok.
I replaced the flasher because the factory one did not flash.

Where do I start?

 

Possible a problem at the fuse box make sure the fuse terminals are not corroded. I had issues with mine it has the glasses fuses and I had to remove all the fuses and clean the terminals with a wire wheel on a Dremel, replace all the fuses with new ones and problem solved

 

I've hooked up a test light and made sure I had power in both sides of all the fuses, probing on the end of the fuses not the brass connectors and they are all good.

But I'll give that a go and see.

 

Often there is corrosion on the end of the fuse and in the brass connector, so the fuse can test ok but power is not going to the connector

 

They are good.

I'm going to try and check the wiring under the truck.

 

Figured it out.

Had a broken wire near the gas tank. All fixed! Brake lights and hazards work now!

 

I just can't seem to win.
Now the turn signals don't work. They come in but don't flash. Ive swapped flashers and still no change.

 

I'm in the same boat as you are. Signals don't flash when headlights are on. Have you considered updating the whole harness?

 

Mine don't flash at all.
They worked fine before I got the brake lights and hazards working.

 

Both sound like a grounding issue, There is a ground on the chassis near the back that grounds all the tail lights brake lights turn signals and backup lights If that is corroded or damaged it will cause all sorts of weird problems.

 

I'll have to look into that.