I have a 83 HR Motorhome on a 82 Ford E350 chassis that is having brake light issues.
Fuse is good, test light lit on both sides but switched it out just in case
Brake switch lights up with test light on one side, again when pedal is pressed on the other.

Previous owner tapped in to the side that gets power only when the pedal is pressed so stabbed in to the wire after the tap, still got light so the tap didn't cause it.
Bulbs are all good in the back.
Turn signals and tail lights still work as does reverse.
​Hazards havent worked since I bought it a year ago.
Haven't tore in to my steering column yet to check the multifunction switch nor have I tried to trace the line back to the lights.

This is because I got stumped when I checked my trailer plug and found I also had no power to the brakes there either but power the rest of the pins.

Also, as a side question, in park and running when I press the brake pedal to shift out of park, my engine idles up then idles back down when I let off of the brake. This just started as well. Or at least I just now noticed it. One or the other....

Suggestions please?

Thank you

 

If a wiring diagram can be supplied, it would help, otherwise. you would either have to physically trace the color wire from the stoplight sw to the multi function sw on back to the rear of the vehicle. The hazard sw could also be the problem..