1998 Plymouth Voyager Help

Instrument cluster consists of electronic analog gauges, various warning lights, and optional tachometer. See Fig. 1 . Vehicles equipped with tachometer have an electronic vacuum fluorescent transmission range indicator (PRND3L), odometer and trip odometer display. Vehicles without tachometer are equipped with a cable-operated transmission range indicator.
Instrument cluster is equipped with the following warning lights:
Battery voltage.
Cruise (speed control).
Door ajar.
Fasten seat belt.
Lift gate ajar.
Low fuel level.
Low windshield washer fluid level.
Traction Control.
The Body Control Module (BCM), which receives input from various sensors, sends display information to instrument cluster and operates gauges. Instrument cluster incorporates a self-test diagnostic feature to identify electronic problems. BCM, Powertrain Control Module (PCM), and Transmission Control Module (TCM) are continuously monitored by the diagnostic system.

NOTE:Testing of instrument panel and gauges requires using a scan tool to check circuits connected to Body Control Module (BCM). See VEHICLE COMMUNICATIONS in BODY CONTROL COMPUTER article.

SELF-DIAGNOSTICS
With ignition off, press and hold TRIP and RESET buttons while turning ignition switch to ON position. Continue to hold TRIP and RESET buttons until odometer window displays CODE (approximately 5 seconds). If problem exists, system will display diagnostic trouble codes. See DIAGNOSTIC CODE CHART table. If no problem exists, Code 999 (end test) will be displayed.
DIAGNOSTIC CODE CHART
CodeDescription
110.......Cluster Memory Fault
111.......Cluster Calibration Fault
905.......No CCD Bus Message From TCM
921.......Odometer Fault From BCM
940.......No CCD Bus Message From PCM

After diagnostic code display ends, instrument cluster will go into each of the following tests in order:
Dim test.
Calibration test.
Odometer segment test.
Electronic Transmission Range indicator segment test.
Dim Test
CHEC-0 will be displayed in odometer window. Instrument cluster will dim Vacuum Florescent (VF) display. If VF displays do not dim, a problem in instrument cluster exists. See BODY CONTROL COMPUTER TESTS in BODY CONTROL COMPUTER article.
Calibration Test
CHEC-1 will be displayed in odometer window. Each of instrument cluster gauges will move sequentially through each calibration point. See GAUGE CALIBRATIONS table. If gauge needle is not calibrated properly, a problem in instrument cluster exists. See BODY CONTROL COMPUTER TESTS in BODY CONTROL COMPUTER article for gauge recalibration procedures.
GAUGE CALIBRATIONS
Gauge Sequence.....Calibration Point
Speedometer
1......0 MPH (0 Km/h)
2......20 MPH (40 Km/h)
3......55 MPH (80 Km/h)
4......75 MPH (120 Km/h)
Tachometer
1.....0 RPM
2.....1000 RPM
3.....3000 RPM
4.....6000 RPM
Fuel Gauge
1.....Empty
2.....1/8 Full
3......1/4 Full
4.......Full
Temperature Gauge
1......Cold
2......Low Normal
3......High Normal
4......Hot

Odometer Segment Test
CHEC-2 will be displayed in odometer window. Each segment of odometer will light sequentially. If any segment does not light, replace instrument cluster.
Electronic Transmission Range Indicator Segment Test
CHEC-3 will be displayed in odometer window. Each segment of electronic transmission range indicator will light sequentially. If any segment does not light, replace instrument cluster.

You need to start a new question specific to your van. This question is ten years old and the people are long gone. Unlike other sites where anyone can chime in, here it becomes a private conversation between you and one or two experts. I only popped in here to see if I could learn something. When you piggyback on this post, it shows up on our list of questions that have received replies already and are ongoing conversations. As such, the rest of us won't butt in or even read your addition. That does you a disservice and won't get you the help you need.

When you post your new questions, please be sure to list the engine size and mileage. We need to know the engine size to look at the right wiring diagrams, and we look at the mileage when making judgements as to best suspects.

You did a dandy job of describing the symptoms and observations and clues, but for those who are reading this when researching other fixes, please be sure to include as much detail as possible.

For your "Fuel" gauge, the sending unit is on the dark blue wire at the fuel pump assembly. Grounding that wire should send the gauge to "Full". When the gauge stays on "Empty", suspect that dark blue wire has a break in it. Given your observation the gauge does move a little, the best suspect is a corroded pair of terminals in a connector.

Another way to approach this requires a scanner so you can view live data. The sending unit is an input to the Body Computer. That computer sends the data to the Instrument Cluster. Select the Body Computer, then "Inputs / Outputs". That will show what that computer is seeing for fuel level. If that is wrong, that wrong information will be sent to the instrument cluster, so the cluster can be ruled out. If the Body Computer is seeing the correct fuel level, then you have to select the Instrument Cluster, then "Inputs", to see what it is seeing. If the correct level is shown, but the cluster displays the wrong level, that proves the Body Computer is working properly, and the Instrument Cluster is not reacting correctly to the level it is being told.

Unlike the extremely reliable thermo-mechanical gauges that worked fine for decades, these are pointers on "stepper" motors. In those, the armature is set to the desired position by pulsing four electromagnetic coils with varying voltages and polarities. GM has a real big problem with these failing, and there are all kinds of repair kits available. I haven't heard of one of these failing on a Chrysler product, but regardless, the self-test you ran proved the gauge is okay.

If you need to test the fuel level sending unit, the resistance is considerably different than the typical 90 ohms we saw in the past. At "empty", yours should read about 1,000 ohms between ground and the terminal in the plug corresponding to the dark blue wire. It should read around 70 ohms at "full".