I have a 2004 ford ranger 4x4 that has some problems, When I turn the lights on the horn goes off, So I took the horn fuse out then the parking lights stay on. They wont go off unless I disconnect the battery. I then put the horn fuse back in and disconnected the horn at the horn. When I turned my lights on the wipers start running. I then cleaned three ground wires and that didn't help. Short of getting an Exorcist does anyone know what's happening.

 

Welcome to the forum

2004-2011 Ranger have the SJB(smart junction box), its the Body Computer, controls all the lights, wipers, horn, anything electrical in the cab or controlled by switches in the cab
(1995-2003 Ranger used the GEM as the body computer)

Your SJB could be bad or it could just be moisture in the connectors, a common issue

The cab fuse box is part of the SJB, so you need to take off the passenger side kick panel to reveal the full SJB

This article has pictures of SJB: https://www.therangerstation.com/tec...horn_mod.shtml

The SJB has 4 Large wire connectors, there is a lever on each that you pull up on, that pushes the connector up and away from the SJB so connector can be removed

Then you need to inspect the connector and its base for corrosion

As seen here: https://i0.wp.com/sparkys-answers.co...0/DSC09930.jpg
Or here: https://guide-images.cdn.ifixit.com/...WCLms5m.medium
Pretty obvious on these, lol
But have a good look for signs of corrosion

If it all looks OK pull out the SJB and check it inside for corrosion

 

Thanks Ron that was the problem water in the box. Works great now.

 

Thanks for the update and THE FIX, it will helps someone else down the road