Found a second problem with my new stang...The brake lights don't work!..its a 1995 5.0 5 speed......Everything else works,turn signals,parking lights, but the bulb that does the brakes light doesn't work. I haven't done any testing yet accept checked the bulbs...Is there any common problem with these? I've looked at all the fuses and they all seem good.
Brake lights not working??
- Thread starter epurdy2005
- Start date
Check the BOO. Since the TS's work, we can assume the fuse is good (it controls the BOO and TS's as I recall).
Does the 3rd brake light work? If it does, the BOO (and fuse) are ok. Power for the outer brake lights run through the MF switch, whereas power for the 3rd brake light does not. That's why knowing if the 3rd one works is important.
If you have no brake lights at all, check in/out voltage at the BOO (be sure the switch is closed when you test output voltage).
Good luck.
Does the 3rd brake light work? If it does, the BOO (and fuse) are ok. Power for the outer brake lights run through the MF switch, whereas power for the 3rd brake light does not. That's why knowing if the 3rd one works is important.
If you have no brake lights at all, check in/out voltage at the BOO (be sure the switch is closed when you test output voltage).
Good luck.
Okay, what's a BOO and where is it located? If the OP knows I don't. TS I assume is the "Turn Signal" based on the context.
Richard
Sorry guys.
BOO = Brake On/Off switch. It's standard nomenclature for our brake light switches (because it's monitored by the EEC, it's no longer simply called a brake switch).
The switch is obviously on the brake pedal assembly.
You got it with TS (my made up shorthand).
MF = Multi-function switch, which is the turn signal switch. Because our tails and brakes share bulbs, the brake light wiring for the body brake lights [not the 3rd one] go through the MF switch.
BOO = Brake On/Off switch. It's standard nomenclature for our brake light switches (because it's monitored by the EEC, it's no longer simply called a brake switch).
The switch is obviously on the brake pedal assembly.
You got it with TS (my made up shorthand).
MF = Multi-function switch, which is the turn signal switch. Because our tails and brakes share bulbs, the brake light wiring for the body brake lights [not the 3rd one] go through the MF switch.
Thanks for clarification of the boo.......On my brake pedal there is the switch that comes out when the brake is pushed which looks okay and then theres something else on there with electrical wires going to it closer to the floor on the brake pedal. What is it? It had some electrical tape on it so maybe somebody has messed with it....I also found a purple neon while I was down tehre which I took out. And no the third brake light isn't working either...Thanks!
bigplansnomoney
New Member
I would assume maybe the wires went to some TRICK ASS neon racing pedals the previous owner may have had to accent his homo purple neons. Where does the other end of that wire run.
Try replacing that brake on/off switch first. If the third brake light functions, your Multifunction should be functioning correctly.
Try replacing that brake on/off switch first. If the third brake light functions, your Multifunction should be functioning correctly.
to check BOO
#1.using test light,touch terminal at BLUE arrow with pedal in normal position.if test lights illuminate.switch is receivlng power.if no power here,check wiring to the BOO switch,also check fuse #9 under dash,should be 15 amp fuse.
#2.press brake pedal down,touch test light to RED arrow.if light illuminates,switch is working.
#3.if switch works,problem is most likely in the wiring.your going to need a wiring diagram,but im sorry i dont have one.
If switch needs to be replaced.
#1.disconnect wiring,BLUE arrow
#2.pull out brown pin,RED arrow.
#3.slide out in direction of PURPLE arrow.make note of the position of the plastic washer and bushing.
#4.install is reverse of removal.
#1.using test light,touch terminal at BLUE arrow with pedal in normal position.if test lights illuminate.switch is receivlng power.if no power here,check wiring to the BOO switch,also check fuse #9 under dash,should be 15 amp fuse.
#2.press brake pedal down,touch test light to RED arrow.if light illuminates,switch is working.
#3.if switch works,problem is most likely in the wiring.your going to need a wiring diagram,but im sorry i dont have one.
If switch needs to be replaced.
#1.disconnect wiring,BLUE arrow
#2.pull out brown pin,RED arrow.
#3.slide out in direction of PURPLE arrow.make note of the position of the plastic washer and bushing.
#4.install is reverse of removal.
StadEMS3
20+ Year Stangneter 
I had a similar issue, I kept blowing the brake light fuse when I pressed the clutch pedal. It turned out that my Steeda aluminum quadtrant wore a small hole in the brake wire. It wouldn't blow the fuse if it was just quickly pushed in for shifting, just when held to the floor grounded it out long enough to blow. What a troubleshooting nightmare that was.
Lee Gardner
New Member
- Feb 5, 2016
- 4
- 0
- 1
Having this issue as well. Power to the BOO comes and goes, but I press the brake and the power goes away, where can I check to find this issue. Thanks guys
to check BOO
#1.using test light,touch terminal at BLUE arrow with pedal in normal position.if test lights illuminate.switch is receivlng power.if no power here,check wiring to the BOO switch,also check fuse #9 under dash,should be 15 amp fuse.
#2.press brake pedal down,touch test light to RED arrow.if light illuminates,switch is working.
#3.if switch works,problem is most likely in the wiring.your going to need a wiring diagram,but im sorry i dont have one.
If switch needs to be replaced.
#1.disconnect wiring,BLUE arrow
#2.pull out brown pin,RED arrow.
#3.slide out in direction of PURPLE arrow.make note of the position of the plastic washer and bushing.
#4.install is reverse of removal.
Old thread but having a similar problem. Brake lights went out after working fine. The chime and dome light still work so I know the fuse is good (also checked it) Here is the weird thing. With the key out of the ignition now if I press the brake pedal the chime goes off and my HVAC panel lights come on. sounds weird right? this was not happening before, and I have touched nothing related to these circuits. I did read where someone with a Camaro had a similar issue and turned out to be shorted bulb, he put a dual filament bulb in. I did just change my bulbs to led, so I am going to pull them out and start there with a voltmeter / old bulbs. Would be nice if it really was just that. Just putting this up here as the symptoms are different.
You have a broken ground someplace.
C279 C211 S303
S302 - Splice near Tape Out next to G201
G201 - Ground in Left Fender Apron
S303 - Splice near Tape Out to windshield wiper
C211 - Connector attached to hazard switch
C279 - On Steering Column near ignition switch
There are Tape Out Grounds at each of these locations. That C279 looks like it might be a bugger to find. Looking at the diagram though, since your brake light and HVAC light are both affected then it should be the grounds at either S302 or S303. I included the others because stranger things have happened when juice has to find it's own path to ground.
Believe it or not, my problem was due to an incorrect bulb that was shorted out. It was one of the marker bulbs. I took out everything I still had all the same symptoms. I put a working marker bulb, and the one that was blown and everything went back to normal. I have since replaced all the bulbs and I am. That is the weirdest symptom for a blown bulb I’ve ever seen.
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