Homerwinzlow: Thanx again. Here is what I have: There are two wires going to the BOO switch. The "upper" one is the light green one and the "lower" is the light green/red stripe.

My light green has current always.
My light green/red stripe has no current except when the brake is depressed (or jumped).

I didn't trace the light green because it had current at the BOO switch.
I traced the light green/red stripe ~15".

 

Hmmm, well let me check my EVTM and see what it says. It is irregular to have the light green full time hot on a Ford.

 

Yep, you have had a blown fuse all this time I suspect. The Light green and red stripe is supposed to be hot from the fuse box, so check fuse 13 at the fuse box. You have feed back voltage at the other side from a short to hot or another device. You should swap out the fuse and see if it blows again. If it does you have many possible sources of a short. Someone suggested checking the cruise deactivation switch and servo early on and I assume you already did that. Possible problems at the trailer harness, multifunction switch, transmission control overdrive switch harness are good places to start. If you have a remote start or alarm those are also possible problem areas.

 

Homerwinzlow: Okay, I gave some bad information. When I was checking for a current, I had my meter on audible. What I was doing (stupidly) was getting a tone from the meter which was indicating continuity (not current). So, when I grounded the one probe and attached the other to the green wire, I got a tone. This was my mistake...but it isn't all bad. That tells me that the ground is good going to the BOO switch.

I again checked the #13 fuse (15A). To be sure, I switched it with the #14 (also 15A - dome light). Therefore, I have a good fuse!

I was under the hood again today. There are 2 harnesses at the Master cylinder. One right on the plastic (at 3 o'clock when standing i the front of the truck. That is probably the next piece of plastic that I'll break trying to remove and inspect it. The other one is at 6 o'clock and is not connected as close to the actual resevoir as the other. That was inspected and is prisitine.

If the green/red wire (at the BOO) should carry a current,(like you stated) and I don't have a reading, then I am thinking that it is a problem before the BOO. My readings were green 0mV and green/red didn't give one (digital meter).

Other information which may or may not be helpful:
-Over the winter (maybe 2 winters ago...can't remember)I cut a wire at the RAP module because my panic would go off at all hours of the day/night. It was the one that controls the horn / lights in a Panic (Horn and lights work otherwise...as does panic function...you just can't tell except for the dash light). Probably not related because the problem would have come up sooner.
-I have had my cruise control recall done recently (March?).
-I seem to remember a problem with my cruise control just before I went in for recall. It was working okay after the service.
-I have a factory trailer wiring harness with rubber cover which sometimes falls out. The contacts in the harness look slightly oxidized (whitened) as I would expect at their age.
-I have no remote start.
-I have no alarm system (other than factory theft deterrent).
-I vaguely seem to remember on a couple of isolated occassions that the OD OFF light was illuminated on the shifter (at times other than when I had deactivated the OD). That hasn't seemed to happen in a couple of years.

Still driving sidestreets avoiding the cops. Ironically, I got pulled over speeding 2 weeks ago. I was one of 2 cars caught at the same time. Smokey pulled alongside and told me over the loud speaker to pull over behind him (after he chased down the other car). The bad news was that I got my first ticket in 10 years, the good news is that he never got to see my brake lights!

 

You are possibly making this a lot more work than necessary. Switch to volts and test for 12v at the brake switch on the green and red wire. Then test for 12v on the other pin light green when pedal is depressed. Then test about 12 inches up the light green wire for 12V with the pedal depressed. That should tell you quite a bit in itself.

 

0 volts at green/red stripe (at BOO harness) and F13 is good.
didn't perform other tests, as they seem to be after the problem

 

Well that definitely leaves the problem between the fuse box and the switch on that circuit. Fuse has voltage on both sides I presume. Also check that someone hasnt been probing the fuse pins in the box trying to find a hot circuit in the past. They can spread the pins too far apart leaving no connection at the fuse even though the fuse is showing current passing through. Never assume the fuse is good, check it with continuity test and inspect the box pin connections.

 

fuse is good.
connectors are good.
12" up the green/red wire shows no current.

what about this idea?
i run a new line with a 15A inline fuse from somewhere and splice it onto the green/red wire (which I will cut about 3" above the brake switch). i will "cap" off the lead coming from the fuse box.

will I:
a) solve the brake light problem
b) create other problems

and:
do you have any suggestions as to where I can steal the hot leg?

as always, thanx, Dan!

 

need to drive up to Boston this weekend ,,,about 250 miles

hoping to get some resolve by then, please assist if possible
please see previous post in thread...thanx!

 

That's a reasonable workaround.

Check the unused fuse slots in the fuse panel for an unused ALWAYS HOT supply and just use a spade terminal and plug into the slot.

You sould always get a fuse tap (Radio Shack sells them) and put the splice on the load side of F13, efectively just jumpering around the open circuit. If you do this, I wouldn't bother removing the dead circuit lead.

Steve

 

i thinkthat i'll do that. the fuse tap is a great idea...wasn't thinking of it.

i'll try too do my repair in the next day or two and i'll be sure to let you you know how i made out. until then, thanks...Dan!

 

gimme a day or two...the heat has me beat!

 

Success!
Thank you all, especially HomerWinzlow.

Afterthought: once you insert a fuse tap, you're pretty much comitted to using it because it will spread the connection in the fuse socket. After I connected a jumper, I found my problem. I decided to fix it and remove the jumper. After that, I didn't have a good connection anymore. So I just left the jumper connected. 45 screws later, I was all put together and more importantly now my wife can stop saying, "Why don't you just take it down to Ford?"

 

Glad for you. BTW I AM FORD... Hehehey... Glad to have helped.

John

 

Sometimes in a pinch if it isnt spread too far apart in the terminals, I will twist the blades of the fuse to enlarge them to fit tight in the box.