Inop speed control

A electronic control module ,BCM body control module or a SJB - smart junction box ford calls their body control module .
Principles of Operation
The smart junction box (SJB) monitors the multifunction switch position by sending multiple voltage reference signals to the multifunction switch. When the multifunction switch is in the LH or RH TURN positions, or the hazard lamp switch is engaged, that input signal is routed to ground.
When the SJB receives a request for a turn signal or hazard lamps, the SJB supplies voltage to the appropriate turn lamps.

• The hazard lamps are inoperative/always on

• Circuitry
• Hazard lamp switch
• SJB

• Go To Pinpoint Test O

Pinpoint Test O: The Hazard Lamps Are Inoperative/Always On
Refer to Wiring Diagrams Cell 90 , Turn Signal/Stop/Hazard Lamps for schematic and connector information.
Normal Operation The smart junction box (SJB) sends a voltage reference signal to the hazard lamp switch through circuit CLS32 (BN/YE). When the hazard switch is engaged, the voltage signal is routed to ground through circuit GD116 (BK/VT). When the SJB detects a request for the hazard lamps, the SJB sends voltage to the appropriate turn lamps.
DTC B1875 - is an on-demand code that sets when the SJB detects a short to ground from the hazard lamp switch input circuit.

Possible Causes
• Circuit CLS32 (BN/YE) open or short to ground
• Circuit GD116 (BK/VT) open
• Hazard lamp switch
• SJB

Use a mighty vac, it's a hand held pump. Available at most parts stores

The pressure switch on the master cylinder has nothing to do with the cruise control . The pressure switch as you call it is not a pressure switch at all . Brake fluid level sensor . The brake switch is under the dash on top of the brake pedal linkage (arm) .
Speed Control The vehicle speed control consists of the following components:

• speed control servo (9C735)
• speed control actuator cable (9A825)
• speed control indicator lamp
• speed control actuator switches (9D743)
• brake pedal position (BPP) switch (13480)
• deactivator switch
• anti-lock brake control module (2C018)
• clutch pedal position (CPP) switch
• Self-Test Diagnostics
  WARNING: This test is a key on engine off (KOEO) test only that is conducted in PARK only with parking brake fully engaged.
  
  • Enter Self-Test Diagnostics by depressing the speed control OFF switch while turning the ignition key ON, making sure the engine does not start and is not running. The speed control indicator lamp on the instrument panel will flash once to indicate that the speed control module entered the diagnostic mode.
  NOTE: Five additional flashes at this point indicate a defective speed control servo. Release the OFF switch.
  
  • Release the OFF switch.
  • NOTE: If the ON switch is not pressed within five seconds after entering the diagnostic mode, the module times out and the procedure must be started over.
    Press the remaining switches in this sequence: ON, RSM (resume), CST (coast), and SET/ACCEL. The speed control indicator lamp will flash as each switch is pressed. Press each switch in the sequence immediately after the light goes out for the previous switch.
  • A lamp flash with the last button (SET/ACCEL) indicates that the STATIC test passed. If the lamp does not flash with the last button and there are no additional flashes of the lamp, the switch is defective. If the lamp does not flash with the last button, and additional flashes occur, follow the chart below for trouble codes:
    • Two flashes - Brake pedal position (BPP) switch is defective, circuit is defective, or brake pedal is applied; clutch pedal position (CPP) switch is defective, circuit is defective, or clutch pedal is applied.
    • Three flashes - Brake deactivation switch is open or circuit is defective.
    • Four flashes - Vehicle speed signal is out of range or circuit is defective.
  • Immediately after the static test has passed, the speed servo will then carry out a dynamic test automatically by actuating the throttle lever from 1mm to 10 mm of travel from the idle position. During the dynamic throttle pull, observe the throttle movement to witness any binding or sticking of actuator cable, correct connection of actuator cable to throttle lever, and make sure the throttle returns back to idle position. If incorrect connection and/or binding or sticking of actuator is observed, go to the Symptom Chart. If dynamic pull at the throttle body is observed, Go To Pinpoint Test A .
  • Return the ignition switch to the OFF position and proceed to the Symptom Chart.
  Symptom Chart

Symptom Chart
NOTE: Self-Test Diagnostics must be carried out before proceeding to the Symptom Chart.
Symptom Chart Condition Possible Sources Action

• Flash code 1 - system pass

• -

• System Pass.

• Flash code 1 - no dynamic pull at throttle body

• Speed control actuator cable.
• Speed control servo.

• GO to Pinpoint Test A .

• Flash code 1 - speed control inoperative

• Circuitry.
• Speed control servo.

• GO to Pinpoint Test D .

• Flash code 2 - BBP switch circuit failure

• Circuitry.
• BPP switch.
• CPP switch or jumper.
• Speed control servo.

• GO to Pinpoint Test B .

• Flash code 3 - deactivator switch

• CJB Fuse 13 (20A).
• Circuitry.
• Deactivator switch.
• Speed control servo.

• GO to Pinpoint Test C .

• Flash code 4 - speed signal circuit failure

• Circuitry.
• Speed control servo.
• Anti-lock brake control module.

• GO to Pinpoint Test D .

• Flash code 5

• Speed control servo.

• INSTALL a new speed control servo. REFER to Actuator - Speed Control Servo . TEST the system for normal operation.

• The speed control is inoperative - no flash codes

• CJB Fuse 10 (7.5A).
• Circuitry.
• BPP switch.
• Speed control actuator switches (9D743).
• Anti-lock brake control module.
• Speed control servo.

• GO to Pinpoint Test E .

• The speed control does not disengage when the clutch is applied

• BPP switch.
• CPP switch (M/T).
• Circuitry.

• GO to Pinpoint Test F .

• The speed control switch is inoperative - COAST

• Speed control actuator switch.
• Speed control servo.

• GO to Pinpoint Test G .

• The speed control switch is inoperative - SET/ACCEL

• Speed control actuator switches.
• Speed control servo.

• GO to Pinpoint Test H .

• The speed control switch is inoperative - RESUME

• Speed control actuator switch.
• Speed control servo.

• GO to Pinpoint Test J .

• The speed control switch is inoperative - OFF

• Speed control actuator switch.
• Speed control servo.

• GO to Pinpoint Test K .

• The speed control indicator lamp is always on

• Circuitry.
• Speed control servo.
• Instrument cluster.

• GO to Pinpoint Test L .

• The speed control indicator is inoperative

• Circuitry.
• Bulb.
• Instrument cluster.
• Speed control servo.

• REFER to Section 413-01 .

• The set speed fluctuates

• Anti-lock brake control module.
• Speed control servo.
• Speed control actuator switch.
• Circuitry.
• Speed control actuator cable.

• GO to Pinpoint Test M .

• Engine (6007).

• REFER to Powertrain Control/Emissions Diagnosis (PC/ED) manual. REPAIR engine as necessary.

Do you know how to test automotive electrical circuit's using a wiring diagram an a DMM - digital multi-meter ? Do you know what a factory diagnostic flow chart is ? This will not set any diagnostic trouble code's in the BCM - body control module . Looking at factory symptom chart , their is no diagnostic trouble chart for your symtoms . Have four choices .
Hazard Lamps Always On
• Hazard Lamps Inoperative
Turn Signal Lamps and/or Indicators Always On or Flashing
• Turn Signal Lamps and/or Indicators Inoperative
Which one would you use to diagnose this problem .
Or would you just view wiring diagrams an wing it ?

Turn Signal Lamps and/or Indicators Inoperative
Step
Action
Yes
No
Schematic Reference: Exterior Lights Schematics
Connector End View Reference: Lighting Systems Connector End Views or Body Control System Connector End Views in Body Control System.
1
Did you perform the Lighting Systems Diagnostic System Check?
YES - Go to Step 2
NO - Go to Diagnostic System Check - Lighting Systems
2
Verify that the turn signal lamps and/or indicators are inoperative.
Do the turn signal lamps and/or indicators operate normally?
YES - Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
NO - Go to Step 3
3
Are only the turn signal indicators in the instrument panel cluster (IPC) inoperative?
YES - Go to Step 4
NO - Go to Step 5
4
Test the inoperative turn signal supply voltage circuit to the IPC for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
YES - Go to Step 21
NO - Go to Step 13
5
Is only one turn signal lamp inoperative?
Go to Step 6
Go to Step 8
6
Inspect the inoperative bulb/socket for an internal short, poor terminal contact, or an open filament.
Was a problem found?
Go to Step 18
Go to Step 7
7
Test for an open, high resistance, or short to ground in the turn signal lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 21
Go to Step 16
8
Inspect the IGN E fuse and the FLASHER fuse.
Is either fuse open?
Go to Step 11
Go to Step 9
9
Test for an open or high resistance in the following circuits:
• The turn/hazard flasher battery positive supply voltage
• The turn/hazard flasher ground
• The turn signal switch ignition 1 supply voltage
Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 21
Go to Step 10
10
Disconnect the multifunction switch, turn signal switch.
Test the multifunction turn signal switch for continuity between the multifunction turn signal switch ignition 1 voltage input terminal and the turn signal flasher signal output terminal in each respective position. Refer to Circuit Testing in Wiring Systems.
Is continuity present?
Go to Step 12
Go to Step 14
11
Test the following circuits for a short to ground:
• The multifunction turn signal switch ignition 1 voltage
• The turn/hazard flasher supply voltage
• The left turn signal switch signal
• The right turn signal switch signal
• The left turn signal lamps supply voltage
• The right turn signal lamps supply voltage
• The trailer left rear turn/stop lamp supply voltage
• The trailer right rear turn/stop lamp supply voltage
Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 21
Go to Step 14
12
Test the following circuits for an open or high resistance:
• The multifunction turn signal switch ignition 1 voltage
• The turn/hazard flasher supply voltage
• The left turn signal switch signal
• The right turn signal switch signal
• The left turn signal lamps supply voltage
• The right turn signal lamps supply voltage
• The trailer left rear turn/stop lamp supply voltage
• The trailer right rear turn/stop lamp supply voltage
Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 21
Go to Step 15
13
Inspect for poor connections at the IPC. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 21
Go to Step 17
14
Inspect for poor connections at the multifunction turn signal switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 21
Go to Step 19
15
Inspect for poor connections at the turn signal/hazard flasher module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 21
Go to Step 20
16
Repair the ground circuit of the inoperative lamp. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?
Go to Step 21
--
17
Important: Perform the set up procedure for the IPC.
Replace the IPC. Refer to Instrument Cluster Replacement in Instrument Panel, Gages, and Console.
Did you complete the repair?
Go to Step 21
--
18
Replace or repair the inoperative bulb/socket.
Did you complete the repair?
Go to Step 21
--
19
Replace the multifunction turn signal switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column.
Did you complete the repair?
Go to Step 21
--
20
Replace the turn signal/hazard flasher module.
Did you complete the repair?
Go to Step 21
--
21
Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 3

If you add to much freon the air compress won't enage and your a/c want come on.

Its either a short or the switch is defective. Remove switch from electrical connector and use an ohm meter to test their resistance.
If resistance is high replace switch.

You would get the correct carburetor instead for electronic computurized controlled carbs will not work on a 1981 Corvette

THERE IS A LOW PRESSURE SWITCH ON ACCUMULATOR.IF THE PRESSURE IS LOW THE COMPRESSOR WON'T TURN ON.CHECK THE FREON CHARGE AS WELL

Check your blower motor fan speed control switch. They go bad frequently. You could have checked the resistor by jumping the wires to the different terminals to be sure the resistor was good. That pretty much just leaves you will the fan speed control switch. Good luck.

Check the blower speed control resistor pack, it is located in the air stream near the blower motor, that is most likely the cause of the inop blower, but be warned if the blower is drawing to much current due to wear the resistor will fail again, I believe the connector has four wires, 2 are heavy Gage