1969 dodge charger fuel gauge inop?

The instrument cluster receives the vehicle speed sensor (VSS) signal which originates in the ABS module and is transmitted to the PCM over the communication network. The PCM monitors the VSS input and sends it to the instrument cluster over the communication network. With the VSS input, the instrument cluster provides the speedometer with a corresponding pointer movement.

• The speedometer/odometer is inoperative

• Powertrain control module (PCM)
• Instrument cluster

• Go To Pinpoint Test F .

Pinpoint Test F: The Speedometer/Odometer Is Inoperative
Normal Operation Vehicle speed information is sent to the powertrain control module (PCM) from the anti-lock brake system (ABS) module. The instrument cluster receives the vehicle speed data from the PCM over the communication network.

Possible Causes
• PCM
• instrument cluster

PINPOINT TEST F: THE SPEEDOMETER/ODOMETER IS INOPERATIVE Your best bet ,have the vehicle hooked to a professional scan tool an checked for DTC'S - diagnostic trouble code's , before you replace parts that are not needed.
Test Step Result / Action to Take F1 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCs) FROM BOTH THE CONTINUOUS AND ON-DEMAND PCM SELF-TESTS

• Check for the recorded PCM DTCs from the continuous and on-demand self-tests.
• Are any PCM DTCs recorded?

Yes
REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual to continue diagnosis of the DTCs.

No
For an inoperative speedometer, GO to F2 .

For an inoperative odometer, GO to F3 . F2 CARRY OUT THE INSTRUMENT CLUSTER SPEEDOMETER GAUGE ACTIVE COMMAND USING THE DIAGNOSTIC TOOL

• Key in ON position.
• Enter the following diagnostic mode on the diagnostic tool: Instrument Cluster Active Command.
• Select the instrument cluster speedometer gauge active command. Trigger the active command on. Observe the speedometer gauge. The speedometer gauge should start 16 km/h (10 mph) and move to 194 km/h (120 mph).
• Is the speedometer gauge within specifications?

Yes
GO to F4 .

No
GO to F5 . F3 MONITOR THE INTEGRATED CIRCUIT DISPLAYS

• Key in ON position.
• Monitor the compass, air temperature and message center functions of the integrated circuit display.
• Do the compass, air temperature, or message center displays operate correctly?

Yes
GO to F5 .

No
Go To Pinpoint Test U to continue diagnosis of the integrated circuit display. F4 CHECK FOR CORRECT PCM OPERATION

• Disconnect all the PCM connectors.
• Check for:
  • corrosion
  • pushed-out pins
• Connect all the PCM connectors and make sure they seat correctly.
• Operate the system and verify the concern is still present.
• Is the concern still present?

Yes
INSTALL a new PCM. REFER to Section 303-14 . TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. F5 CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION

• Disconnect all the instrument cluster connectors.
• Check for:
  • corrosion
  • pushed-out pins
• Connect all the instrument cluster connectors and make sure they seat correctly.
• Operate the system and verify the concern is still present.
• Is the concern still present?

Yes
INSTALL a new instrument cluster. REFER to Instrument Cluster in this section. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

Odometer The instrument cluster receives odometer rolling count status from the PCM-engine computer and stores the mileage in non-volatile memory (NVM). When the instrument cluster fails to receive the odometer rolling count status for more than two seconds, the odometer display will show dashes.

HEC Dealer Test Mode
To enter the HEC Dealer Test Mode, depress and hold the instrument cluster SELECT/RESET button and then turn the ignition switch to the RUN position. Continue pressing the SELECT/RESET button (5 seconds) until tESt is displayed in the odometer. The SELECT/RESET button must be released within 3 seconds of the odometer displaying tESt to begin the dealer test mode. Depress the SELECT/RESET button to advance through the following steps until dtc is displayed. Depressing the SELECT/RESET button will display any continuous DTCs stored before proceeding to the next step.

All segments illuminated Illuminates all odometer segments. If any odometer segment is inoperative, INSTALL a new instrument cluster; REFER to Instrument Cluster .
Odometer Display Description GAGE Activates gauge sweep of all gauges, then displays present gauge values. Also carries out the checksum tests on ROM and EE. If the gauge sweep is inoperative, INSTALL a new instrument cluster; REFER to Instrument Cluster . All segments illuminated Illuminates all odometer segments. If any odometer segment is inoperative, INSTALL a new instrument cluster; REFER to Instrument Cluster . bulb Illuminates all micro-controlled lamps and LEDs (low oil pressure/high coolant temperature, low fuel, service engine soon, brake, low range). INSTALL a new bulb or LED as necessary. r Returns to normal operation of all micro-controlled lamps and LEDs and displays hexadecimal value for ROM level (used when requesting assistance from the hotline). If alternating flashes of FAIL and ROM level are displayed, INSTALL a new instrument cluster; refer to Instrument Cluster . EE Displays hexadecimal value for EE level (used when requesting assistance from the hotline). If alternating flashes of FAIL and EE level are displayed, INSTALL a new instrument cluster; refer to Instrument Cluster . dt Displays hexadecimal coding of final manufacturing test date (used when requesting assistance from the hotline). dtc Displays continuous DTCs. Pressing the SELECT/RESET button will display any DTCs stored before proceeding to the next step. enG Displays the English speed in mph. Speedometer will indicate present speed within tolerances. Display will show 0 if input is not received, if input received is invalid for one second or more, or if speed is 0. m Displays the English speed data (mph) received from the PCM via SCP Network. Displays the metric speed in kph. Speedometer will indicate present speed within tolerances. Display will show 0 if input is not received, if input received is invalid for one second or more, or if speed is 0. tAc Displays the tachometer data received from the PCM via the SCP Network. Tachometer will indicate present speed within tolerances. Display will show 0 if input is not received, if input received is invalid for one second or more, or if engine rpm is 0. FUEL Displays the actual A/D fuel level. The fuel gauge will display a filtered fuel level value. This filter will keep the pointer from moving suddenly or erratically. If the value displayed is between 0 and 20, the circuit is shorted. GO to Pinpoint Test D .

• 255=open send +/-0
• 232=Full stop +/-10
• 215=Full mark +/-10
• 178=3/4 mark +/-8
• 138=1/2 mark +/-7
• 93=1/4 mark +/-5
• 41=E mark +/-4
• 54="LOW FUEL" (0-59)
• 0-18=short (0-20 max.)

OIL Displays the code (0-255) for the oil pressure switch input to the HEC. Displays the oil pressure reading input to the HEC. Oil pressure gauge will indicate present oil pressure. Normal oil pressure (greater than 6 psi) will display a value between 000 and 176. A low oil pressure (less than 6 psi) or an inoperative engine oil pressure switch will display a value greater than 176. dEGC Display of engine temperature in Degrees C input from cylinder head temperature sensor. If the value displayed is -40C, the SCP message for engine temperature has not been received for more than 5 seconds. GO to Pinpoint Test E .

• 49 C="C" mark.
• 60 C=Normal band start.
• 120 C=Normal band end.
• 119 C=Temperature warning indicator ON.
• "-40" C=No SCP Message for 5 sec.

br Displays the brake fluid level input to the HEC. bAtt Displays the code (0-255) battery voltage input to the HEC. Battery voltage gauge will indicate present battery voltage.

• 93-102=6.9-9.1 volts (Low voltage)
• 115-124=8.5-10.7 volts (Norm band start)
• 215-225=15.8-18 volts (Norm band end)
• 230-241=16.9-19.1 volts (High voltage)

rhEo Displays the present hexadecimal value for the instrument cluster backlighting pulse width modulated (PWM) input to the HEC (used when requesting assistance from the hotline). rhi
rhS
rho PWM input duty cycle.
SCP hexadecimal dimming step (used when requesting assistance from the hotline).
Output driver counts in hexadecimal format (used when requesting assistance from the hotline). Cr Displays the present RUN/START sense input. Display will show -h with the ignition switch in the START position and -L with the ignition switch in the RUN position. ALtF Displays 8-bit hexadecimal value for alternate fuel level. Display will show a value between 00 and FF if the message is received. PA-PE7 Not used. GAGE Repeats test display cycle.
Turn the ignition switch to the OFF position or press and hold the SELECT/RESET button for 3 or more seconds and release to exit HEC Dealer Test Mode. If no DTCs related to the concern are retrieved, proceed to the Symptom Chart to continue diagnostics.

Principles of Operation
The instrument cluster and panel illumination consists of dimmable and non-dimmable illumination components. The dimmable illumination is controlled by the instrument panel dimmer switch, which allows the brightness level of the backlights to be adjusted to the customer preferences. With the parking lamps ON, the instrument panel dimmer switch uses electronic circuitry to provide a variable pulse width modulated (PWM) output to the instrument panel and all applicable switches depending on the driver-controlled level of intensity. The headlamp switch backlighting consists of 2 constantly illuminated LED bulbs that are powered by separate circuits. Battery voltage is supplied to the first bulb when the ignition switch is in the RUN position. Battery voltage is supplied to the second bulb with the parking lamps ON. The non-dimmable illumination allows for full intensity dependant on the ignition switch position.

Inspection and Verification

1. Verify the customer concern.

1. Visually inspect for obvious signs of mechanical or electrical damage.

Visual Inspection Chart Mechanical Electrical

• Headlamp switch
• Instrument panel dimmer switch

• Circuitry
• Connector(s)
• Headlamp switch
• Instrument panel dimmer switch
• Illumination source(s)

1. If an obvious cause for an observed or reported concern is found, correct he cause (if possible) before proceeding to the next step.

1. If the cause is not visually evident, verify the symptom and GO to Symptom Chart .

Symptom Chart
Symptom Chart Condition Possible Sources Action

• The control illumination is inoperative

• Headlamp switch
• Circuitry

• Go To Pinpoint Test A .

• The instrument cluster illumination is inoperative

• Circuitry
• Instrument cluster

• Go To Pinpoint Test B .

• The climate control panel illumination is inoperative

• Circuitry
• Climate control panel

• Go To Pinpoint Test C .

• The audio unit illumination is inoperative

• Circuitry
• Audio unit

• Go To Pinpoint Test D .

• The transmission control lever illumination is inoperative

• Circuitry
• Transmission control lever illumination bulb

• Go To Pinpoint Test E .

• The hazard warning switch illumination is inoperative

• Circuitry
• Hazard warning switch

• Go To Pinpoint Test F .

• The traction control switch illumination is inoperative

• Circuitry
• Traction control switch

• Go To Pinpoint Test G .

• The window control switch illumination is inoperative

• Circuitry
• Window control switch

• VERIFY the operation of the window control switch in question. If the window control switch is inoperative, REFER to Section 501-11 . If the window control switch operates correctly, INSTALL the new window control switch in question. REFER to Section 501-11 .

• The instrument panel illumination does not dim

• Headlamp switch
• Circuitry

• Go To Pinpoint Test H .

Pinpoint Test B: The Instrument Cluster Illumination Is Inoperative
Normal Operation A variable pulse width modulated (PWM) voltage is supplied to the instrument cluster through circuit 29S-LA31 (OG/BU). The instrument cluster is grounded through circuit 91-GG14 (BK/OG).

Possible Causes
• circuit 29S-LA31 (OG/BU) open
• circuit 91-GG14 (BK/OG) open
• instrument cluster

PINPOINT TEST B: THE INSTRUMENT CLUSTER ILLUMINATION IS INOPERATIVE CAUTION: Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(s) may damage the connector.

Sorry but it's not a fuse problem . There is not a fuse just for the speedometer . The microprocessor inside the instrument cluster determines where the speedometer needle points , just like the fuel gauge , tachometer etc... Having the vehicle checked for DTC'S would be the proper step to take .
Vehicle Speed Signal
The vehicle speed signal is generated by the rear anti-lock brake sensor and sent to the 4-wheel anti-lock brake system (4WABS) module. The 4WABS module sends the vehicle speed signal via circuit 679 (GY/BK) to all systems which require a vehicle speed signal input.
Speedometer
The electronic speedometer receives a speed signal from the 4WABS module.

• The Speedometer/Odometer Is Inoperative

• Circuitry.
• Speedometer.

• GO to Pinpoint Test E .

No where in this factory diagnostic step does it say to check a fuse !

PINPOINT TEST E: THE SPEEDOMETER/ODOMETER IS INOPERATIVE CONDITIONS DETAILS/RESULTS/ACTIONS E1 CHECK THE VOLTAGE TO THE INSTRUMENT CLUSTER
Instrument Cluster
Measure the voltage between instrument cluster C288-7, circuit 1001 (WH/YE), and ground.

• Is the voltage greater than 10 volts?

Yes GO to E2 .

No REPAIR circuit 1001 (WH/YE). TEST the system for normal operation.
E2 CHECK THE INSTRUMENT CLUSTER PRINTED CIRCUIT
Instrument Cluster
NOTE: Measurements must be made to the speedometer gauge pins that are inside the instrument cluster printed circuit clips.

Measure the resistance between the speedometer pins (which can be seen in the middle of the instrument cluster printed circuit clips) and the corresponding instrument cluster terminal. Refer to the table for the pin and terminal assignments.

Instrument Cluster Terminal Speedometer Gauge Pin C286-13 C287-1 S C287-2 G C288-7 BATT
.

• Are the resistances less than 1 ohm?

Yes GO to E3 .

No INSTALL a new instrument cluster printed circuit. REFER to Instrument Cluster Printed Circuit . TEST the system for normal operation.
Your best bet , take it to a qualified repair shop

I'd have to check voltage and ground for the instrument cluster. I noticed one of the fuses for your instrument cluster goes hot with the key on, same thing for ac compressor. I'd have to voltage feed to and from ignition switch for applicable fuse. Check the ignition switch wiring connector. I can't rule out ignition switch itself, at the moment.
There could be other issues?
Ignition switch faults are common on some makes and models.
Instrument cluster wiring connector problems. Sometimes if you disconnect and reconnect the instrument cluster connector, it may start working again, also, cycling the instrument cluster connector may reset, if it starts working, well, it's working for now, may quit again.
Some instrument clusters may do a self test, don't know about yours?
Press and hold odometer reset button, turn key to run position release odometer reset button, watch the odometer. Your indicator lamps may turn on and off, the gages may cycle in small increments. The cluster will exit self test on its own.
You may have to check buss circuits.

There is not a single fuse for the fuel gauge , there are a few that power up the whole instrument cluster ! If there were a fuse out more then just your fuel gauge wouldn't work .You probably have a bad sending unit in the fuel tank or the stepper motor for that gauge is bad ! The thing to do would be to take to the dealer or some other capable ASE certified repair shop that has a up scale scan tool that can check codes in the instrument cluster ! Or you can take a chance an replace the instrument cluster !
Fuel Gage Inaccurate or Inoperative
Inspect for any stored instrument cluster Diagnostic Trouble Codes (DTCs). Are any DTCs stored in memory?
--
Go to Diagnostic Trouble Code (DTC) List/Type
Go to Step 3

3

1. Install a Scan Tool scan tool.
2. Turn the ignition switch to the RUN position.
3. Establish communication with the instrument cluster.
4. Select special functions under the main menu.
5. Select output control under special functions.
6. Select fuel gauge sweep test under output control main menu.

Does the fuel gauge perform a full sweep when commanded?
--
Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls - 3.1L
or
Powertrain On Board Diagnostic (OBD) System Check in Engine Controls - 3.8L
Go to Step 4

The GEM has nothing to do with it !
Odometer/Trip Odometer
The odometer and trip odometer are displayed in the integrated circuit LCD display. The instrument cluster records the total mileage of the vehicle using information received from the PCM, and electronically displays this information in the LCD. If this information is not received, the LCD displays all dashes. How did you prove that instrument cluster isn't bad ?
Did you have a factory scan tool hooked up , check for DTC'S - diagnostic trouble code's ? View data to the instrument cluster etc...
Instrument Cluster Diagnostic Trouble Code (DTC) Index DTC Description Source Action B1202 Fuel Sender Circuit Open Instrument cluster Go To Pinpoint Test B . B1204 Fuel Sender Circuit Short to Ground Instrument cluster Go To Pinpoint Test B . B1205 EIC Switch-1 Assembly Circuit Failure Instrument cluster INSTALL a new instrument cluster. REFER to Instrument Cluster in this section. TEST the system for normal operation. B1342 Instrument Cluster Is Defective Instrument cluster CLEAR the DTCs. REPEAT the self-test. If DTC B1342 is present, INSTALL a new instrument cluster. REFER to Instrument Cluster in this section. TEST the system for normal operation. B1359 Ignition Run/ACC Circuit Failure Instrument cluster Go To Pinpoint Test A . B1317 Battery Voltage High Instrument cluster Go To Pinpoint Test N . B1318 Battery Voltage Low Instrument cluster Go To Pinpoint Test N . U2199 Invalid Data for Engine Coolant Instrument cluster Go To Pinpoint Test D .
Your best bet ,take it to a qualified repair shop.

• The speedometer/odometer is inoperative

• Powertrain control module (PCM).
• Instrument cluster.

• Go To Pinpoint Test F .

When testing a fuel guage you should disconnect the wires to it,guage should read over full,ground the float wire,turn off key then turn back on should read empty.You have to cycle the key for guage to move.If still inop the wire is broken in the harness between the tank and the dash.Voltage on the float wire is low.When tested with a test light it will barely light the light and pulsate.This test indicates the wiring is good.

Fuel Level Indication System The fuel level indication system is a magnetic gauge system. It consists of a magnetic fuel gauge (9280) mounted in the instrument cluster (10849) and a sending unit located in the fuel tank (9002) with an instrument cluster gauge amplifier (10E849) in series between the two. No instrument voltage regulator is used with this system. Fuel Gauge
The magnetic gauge movement consists of three primary coils, one of which is wound at a 90-degree angle to the other two. The coils form a magnetic field which varies in direction according to the variable resistance of the sender unit which is connected between two of them. A primary magnet, to which a shaft and pointer are attached, rotates to align to this primary field, resulting in pointer position. The bobbin/coil assembly is pressed into a metal housing which has two holes for dial mounting. There is no adjustment, calibration or maintenance required for these gauges. The instrument cluster amplifier is calibrated to the fuel gauge. The instrument cluster amplifier and fuel gauge must be replaced as a system. Instrument Cluster Gauge Amplifier/Check Gauge Module
The instrument cluster gauge amplifier electrically averages fuel sender readings so the fuel gauge displays actual fuel level and not fluctuations due to sloshing in fuel tank. The instrument cluster gauge amplifier is a small printed circuit board which latches into a pocket on the back of the instrument cluster. The electrical connections for ignition, ground, input from fuel sender and output to fuel gauge are made through a spring-type connector on the instrument cluster gauge amplifier to the instrument cluster printed circuit (10K843) on the instrument cluster. There are no provisions for calibration or adjustment of the instrument cluster gauge amplifier.
Fuel Sending Unit
The fuel sending unit consists of a variable screened resistor made up of a ceramic substrate. It is controlled by the action of an attached float in the fuel tank. When the fuel level is low, resistance in the sending unit is low. When the fuel level is high, the resistance in the sending unit is high. As the float moves from empty to full, the resistance will gradually and continuously increase.