93 SHO no brake lights

[intraspec676]

Hi I have a 93 SHO and the brake lights don't work.
The cruise control doesn't work either. Also it won't shift out of park.
I replaced the switch on the brake pedal but still nothing.
Does anyone know what it could be?? please help..

 

[nothingtoseehere]

Check the fuse for the BOO switch. As for cruise control, could be a number of things. Could have a broken or disconnected line

 

[BlackonBlack89]

Check on the brake pedal. There's a sensor BOO) there which also is used to turn off the cruise control. It also controls the lights. In my case the wire going into the senor was pulled out.

 

[TwistedD85]

Brake On Off Switch. They're cheap and easy to replace. I had to change mine not too long ago, switched it out right in the Advance Auto parking lot. If I remember correctly you need a flathead screwdriver for the connector and a pair of pliers for the big clip holding everything together, don't forget the plastic washer if it falls and rolls away otherwise everything will be loose.

 

[intraspec676]

I checked the fuse for the Boo switch it was blown so I replaced it when I did smoke came from under the hood drivers side and then the fuse blew. what could it be?

 

[Bill Strobel]

I checked the fuse for the Boo switch it was blown so I replaced it when I did smoke came from under the hood drivers side and then the fuse blew. what could it be?

A short circuit.

 

[intraspec676]

I now have brake lights I unplugged the ABS That's where the smoke was coming from.
The plug was fried as well as the ABS unit itself .
Does anyone know how to diagnose The ABS to tell what fried it?

 

[javve]

I could really use some confirmation on what would cause this. I too have the fuse blowing with the key off.

I have a 93 SHO sedan with the 3.2L Auto tranny.

I hear a little bit of a whirring sound. Nothing has smoke checked, but the fuse goes right away. I suspect it's from the driver side. I unplugged the cruise control module and it still blows.

I have read on another forum that the cruise control switch will cause problems because it's connected to the brake switch and throws people off because the brake switch and cruise control are otherwise on seperate circuits. I'll try to unplug the anti lock braking module tomorrow and see if I blow another fuse.

 

[SuperHO]

lemme guess...the harness you unplugged was a long thin one, directly under the master cylinder? common problem for ATX cars. first off, that's the plug for the cruise control. what happens is the master cylinder decides over time to dribble some brake fluid down on that plug, causing it to short.

 

[javve]

Yes that's the plug but it's still blowing fuses so going to try the ABS plug next as I read that somewhere. It's either that or the cruise switch in the column.

 

[Eastcoast SHO]

lemme guess...the harness you unplugged was a long thin one, directly under the master cylinder? common problem for ATX cars. first off, that's the plug for the cruise control. what happens is the master cylinder decides over time to dribble some brake fluid down on that plug, causing it to short.

i could be wrong but isnt that the part that had the recent recall???

 

[Eastcoast SHO]

I now have brake lights I unplugged the ABS That's where the smoke was coming from.
The plug was fried as well as the ABS unit itself .
Does anyone know how to diagnose The ABS to tell what fried it?

where in ct are you?

me personally as long as your brakes work,and nothing else is smoking or shorting out; i wouldnt worry about it, cant stand abs

 

[projectSHO89]

The 93-95 ATX SHOs were included in the 05S28 Speed Control Disconnect fiasco ...er recall.

The SCDS, mounted on the bottom of the SHO's master cylinder, fails internally and allows the brake fluid to enter the electrical circuit of the switch. Depending on how the fluid flows, it can either short to ground completely (which blows the fuse) or partially. If it shorts partially, the heavy current can cause the connector to smoke or in extreme cases, cause a fire whcih may lead to loss of the vehcile and anything surrounding it.

Apparent side effects of blowing the fuse include no brake lights, no cruise, and an inability to shift the ATX out of PARK.

This same switch failure on the F150/Expedition has resulted in numerous vehicle fires with collateral damage.

If you are an owner of a 93-95 ATX, call your Ford dealer and schedule the free recall service. If your SCDS is working normally, they will install an additional harness that contains a fuse link to protect the vehicle in the event the switch fails with a short circuit. If the switch's connector shows visible signs of fluid leakage, they will also replace the switch.

 

[javve]

I'll have to see about getting it to a dealer for the recall. I would imagine that is the sensor that screws into the bottom of the master cylinder? I always thought the deactivation switch was tied to the brake switch under the dash. I'll unplug this switch and clean it out, and see if I blow a fuse with the switch unplugged.

 

[projectSHO89]

The SCDS is a redundant safety disconnect. It is there to interrupt power to the cruise servo in the event that the brake light signal does not work. The SCDS is supposed to open when the pressure in the master cylinder exceeds a certain threshold that is significantly greater than would be seen by the usual "tapping" of the pedal to disengage the cruise.

 

[javve]

Yup it is SCDS. I unplugged it and put a fuse in.. no sparks or blown fuse!

So now I have brake lights, now to just wait to get time to get the car in to the dealership. Checked my VIN and it's still an open recall.

 

[mclark]

Check on the brake pedal. There's a sensor BOO) there which also is used to turn off the cruise control. It also controls the lights. In my case the wire going into the senor was pulled out.

where is that sensor located,