My horn just started working but now cruise works sometimes lights for the ac adjustments went out and odometer goes on and off and fades out ???????

 

Have you checked your battery to see if it needs to be replaced? Also check your charging system too. These tests can be done for free at most leading auto parts stores.

I also recommend checking the fuse box to see if water is getting in there. Along with checking the floor pans to see if the windshield is leaking and getting into the electrical.

 

Do you have any idea what model year your truck is? Might help to know the engine it has in it too, if you could figure that out.

And, do you know how long you've been having these problems? Do we infer that before this the horn was not working but that the cruise control, lights for the AC and odometer WERE working?

Do you know if you've done any electrical modifications on your vehicle?

- Jack

 

David's got a: 2001 f150 4.2 5speed

According to his previous post about an EGR valve issue.

 

Then I think your previous post about checking for water leaks was spot on!

- Jack