1990 525i Dash Freak OUT!!??

step 1
Remove the left sound insulator
step 2
the stop switch is here, way way up top
use flash light to see it.
it is there.
top of pedal it is there. SM books step1.

buy the service manual.?
if the switch ever sticks on , cruise ENDS
it is a NO, switch normally open contarts
no calibration is stated so its PnP

How do you know brake pedal positioning sensor needs to be replaced ? Traction light on ? DTC'S - diagnostic trouble code's stored . That's why cruise won't engage . Taking your vehicle to a qualified repair shop an having it diagnosed is what you should do.
Cruise Control Inhibited
The engine control module (ECM) inhibits the cruise control operation when any of the following conditions exist:
• The ECM has not detected a brake pedal activation from the body control module (BCM).
• A Cruise Control System DTC has been set.
• The vehicle speed is less than 40.2 km/h (25 mph).
• The vehicle speed is too high.
• The vehicle is in PARK, REVERSE, NEUTRAL, or 1st gear.
• The engine RPM is too low.
• The engine RPM is too high.
• The system voltage is not between 9-16 volts.
• The Antilock Brake System (ABS)/Traction Control System (TCS) is active for more than 2 seconds.

Do the stop lamps work ?
DTC P0703 Brake Switch Circuit 2
The body control module (BCM) monitors the brake pedal position sensor. When the brake pedal is applied, the BCM detects a predetermined voltage signal. The BCM sends a GMLAN serial data message to the powertrain control module (PCM) indicating the status of the stop lamps.

DTC P1574 Stop Lamp Switch Circuit
The stop lamp switch signal circuit is a direct hardwire input to the throttle actuator control (TAC) module from the body control module (BCM). The TAC module monitors the stop lamp switch signal circuit in order to detect when the brake pedal has been applied. When the brake pedal is pressed, the BCM sends a GMLAN serial data message to the powertrain control module (PCM) indicating that the brake pedal has been applied. The BCM also sends a high voltage signal on the stop lamp switch signal circuit to the TAC module. The TAC module sends a universal asynchronous receiver transmitter (UART) serial data message to the PCM indicating that a brake pedal application has occurred. The PCM will compare the UART serial data message and the GMLAN serial data message in order to confirm that both serial data messages match.

Replace Fuel Pump .

Yes it may be the wires are shorting or its actually the problem with instrument cluster.
Also get the vehicle scanned for any error codes stored in computer this will confirm whether is short circuit issue or actual problem:------
I suggest you few help links with accurate solutions to refer/go through:----Click the link below:------

Battery and brake Warning lights on Dash
http://alltypesofpartsreplacing.blogspot.com/2012/10/battery-and-brake-warning-lights-on-dash.html
--------------2002 Ford Windstar: Brake Warning Light ON dash? http://schematicsdiagram.blogspot.in/2012/06/2002-ford-windstar-brake-warning-light.html
-------------ABS & Brake warning lights remains steady on dash? http://schematicsdiagram.blogspot.com/2011/12/abs-brake-warning-lights-remains-steady.html
-----------Chevrolet Tahoe Hood open warning on dash and alarm sounds? http://schematicsdiagram.blogspot.com/2011/12/chevrolet-tahoe-hood-open-warning-on.html
-----------2005 Chevy Impala: Service Vehicle Soon Warning Light? http://whoisbyme.blogspot.in/2012/06/2005-chevy-impala-service-vehicle-soon.html -------------- Malfunction Indicator Light ON http://whoisbyme.blogspot.in/2012/06/malfunction-indicator-light-on.html
-----------Car Runs Fine But Check Engine light is ON?

http://whatisbyme.blogspot.in/2012/05/car-runs-fine-but-check-engine-light-is.html

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Check engine light with codes P2195 and P2197?

http://howtobyme.blogspot.in/2012/01/check-engine-light-with-codes-p2195-and.html

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How to Read Codes from Check Engine Light? http://schematicsdiagram.blogspot.com/2011/12/how-to-read-codes-from-check-engine.html
-------------These will help.Thanks.

lot of Chrysler product do the maybe a wire in the dash that has under or came a loose

The fuse panel is located underneath the dash, to the left of the steering column, next to the emergency brake pedal. You need to remove the under-dash insulation to access some parts of the fuse panel.


If it doesn't have a diagram inside the box, here's one I found online: http://www.coolcats.net/tech/reference/images/fusepanel.jpg


1 15A Lt. Blue Stop Lamps, Hazard Warning Lamps, Speed Control, Cornering Lamp Relays 2 6A - CB - Windshield Wiper/Washer Pump 3

Spare - Not Used 4 15A Lt. Blue Taillamps, Parking Lamps, Side Marker Lamps, Instrument Cluster Illumination, License Lamps, A/C and Heater Illumination, Radio Illumination, Digital Clock Illumination, Autolamp Relay 5 15A Lt. Blue Turn Signal Lamps, Electronic Day/Night Mirror, Lighted Vanity Mirrors *, Backup Lamps, Illuminated Entry, Keyless Entry, Cornering Lamps 6 20A Yellow Rear Defrost Timer, Chime, Back-Up Lamps, Cornering Lamps, Rear Reading Lamps, Trunklid Release, Digital Clock Display, Illuminated Entry, Anti-Theft Module, Turbo Buzzer 7 15A Lt. Blue Fog Lamps (Turbo Only) 8 15A Lt. Blue Courtesy Lamps, Key Warning Buzzer, Illuminated Entry Module, Glove Box Lamp, Door Lock Relays, Radio Memory, Cluster Memory, Outside Mirrors, Tripminder Module, Analog Clock, Anti-Theft Relay 9 30A Lt. Green A/C Heater Blower Motor 10 20A - CB - Horn, Cigar Lighter, Fuel Filler Door, Flash-to-Pass, Speed Control 11 20A Yellow Radio, Tape Player, Premium Sound Amp, Power Antenna, Graphic Equalizer 12 20A - CB - Power Seats, Power Locks, Keyless Entry 13 5A Tan Instrument Cluster Illumination, Radio, Climate Control 14 20A - CB - Power Windows, Power Moonroof 15 10A Red Taillamps, Rear Side Markers, License Lamps, Electoluminescent Coach Lamps 16 4A Yellow Electronic ATC 17 15A Lt. Blue Electronic Cluster, Tripminder Display, Fuel Gauge (non-electronic cluster), A/C Clutch, Speed Control Module, Graphic Warning Display Module, Electronic Blower Speed Controller 18 10A Red Warning Indicator Lamps, Autolamp System, Throttle Position Sensor, Low Fuel Module, Dual Timer Chime, Tachometer, Washer Fluid Level Indicator

locate the relay for the heater/ac control. it is likely located in the fuse panel under the dash and replace it. the second culprit may be the resistor block that controls the speeds of the fan. it is located in the ductwork under the dash close to the fan itself. fairly easy to spot as there will be a wiring harness plug that goes to it. two to three bolts hold it in place. they have a tendency to rust and may possibly be shorting out. check the relay first tho

if it shows a light on the dash, then its best off,unless you need it.really only of use to a spirited driver(speed freak).

There is only one wire to the emergecy brake, when it is grounded it completes the circuit to the light.

You need to take it to the shop. If you don't have the diagnostic tools for this one you are hosed. I am all for do it your selfers, but this is not a simple thing. You are talking about possibly taking your dash apart. This is why the techs make the big bucks. Sorr