Hi, I just spent 1/2 hr on the internet trying to find a diagram of the fuse box of my E350 / Travelaire motor home. No success.
2 of 2 break lights don't work, sometimes/ or forever - I don't know at this time.
Before running into wiring I prefer to go for a possible fuse defect.
I replaced a fuse recently [7/8x1/4 glass tube) to get rear and flashers working. As I was solo and it was day time I could then not check break lights. [Ford vendor did not have a ford-compatile fuse ... !]

I don't like to randomly remove fuses, some of them look not so good; these may still work well if untouched. I don't want to break them. I had a hard and long time finding the 7/8" long fuse. If more unusual dimensions break I increase the problem size. So I am looking for the fuse layout diagram which is in the the vehicle manual I don't have.
I found not library in fordforum.com.
Thanks for your help.

 

There is a nice simple way to check the fuses without removing them.
Invest in a test light. If you get a decent one it will serve you well for a long time.
Then you connect the test light clip to a good ground and probe both sides of each fuse.
Some will have power on one side all the time and others will only have power on one side only when the key is in the on position.
Now, if a fuse has power on one side , it should have power on the other side also.
If not, the fuse is open. It's that simple. You would check every fuse the same way without removing it unless it is defective/ open. It's a great time saver and you will get many years of good service from a quality test light, referred to as heavy duty.

If the fuses are all good , use the test light to check the stoplight switch attached to the brake pedal arm. It should have power all the time on one terminal and on the other terminal when you depress the brake pedal. If not the switch is defective. Some vehicles required the key to be on for stop lights to work.

 

excellent recom. thanks. I usually carry voltmeters, not on this trip. Still hoping for a diagram.

 

When you are checking for poor connections as suspected in this case, a voltmeter requires such a low current to provide a reading it could indicate 12 volts and yet not be a good enough connection to lite the test lite. You either should put some kind of load on the circuit or perform a voltage drop test on the circuit(s).