91 Dodge Caravan Intermittent Instrument Cluster

Due to intermittent failures of the instrument cluster, my wife took into one of the local garages while I was out of province last year. Said garage replaced instrument cluster with a used one. Worked for a bit and then started acting up again. Same story next time she took it in. Wife said it seem to be worse in wet weather (though I have personally seen it die during this hot last summer). The unit now displays absolutely nothing except for a couple of momentary lights while starting the vehicle and "Check gauges" constantly on while operating the vehicle.

My Chilton's points to a defective instrument cluster voltage regulator, poor ground etc.

Seems Google only returns hits for such a voltage regulator up to '89; can anyone confirm this?

If indeed, the '91's have a voltage regulator, information as to where it's located on the vehicle would be appreciated.


<added later on>

After reading on similar situations in this forum, I've checked the instrument cluster connectors and AFAICT there are no cold solder joints, loose pins etc.


A website reference to the pinout for this connector and/or location of the grounding point(s) would be really helpful.

Any thoughts, suggestions or references on this topic would be much appreciated...thanks! :-)

 

Dodge did a recall up to year 2007, for that exact matter. Give me a call at 817-986-7654 I will walk you through,

Nick

 

If you get yourself a factory service manual, you'll have all the pin outs and wiring diagrams you need to determine the appropriate values. there is NO recal on instrument clusters for gen2 minivan clusters. infact, i contacted NTSB and searched every recall for vans and there isn't one recall for any year van for instrument cluster replacement.

 

There was a technical service bulletin for the cluster locking up and how to diagnose the condition. It does require the use of a scan tool but it should help.


NO: 08-14-92

SUBJECT: Instrument Cluster Gauges/Warning Lamps Inoperative/Intermittent Operation Of Body Controller Functions

DATE: Aug. 10, 1992

SYMPTOM/CONDITION:

Instrument cluster gauges will not operate. In addition, the chime, intermittent wipers, power door locks, illuminated entry, instrument panel illumination, and warning lamps may not function correctly. The overhead console will only display compass and temperature correctly.
These symptoms may be caused by three different conditions. These conditions are; (1) mechanical cluster warning lamp lock-up, (2) body controller lock-up caused by the relays, or (3) body controller lock-up due to electrostatic discharge (a shock from static electricity).
DIAGNOSIS:

MECHANICAL CLUSTER

1. Verify that one of the conditions exists by turning the ignition switch to the ON position (several OFF-ON ignition cycles may be required), and observing the instrument cluster.
2.  
   1. If ALL of the warning lamps come on and NONE of the gauges operate, the cluster PC board is locked up. Go to REPAIR PROCEDURE 1.
   2. If NONE of the warning lamps or gauges operate, refer to the cluster diagnostic procedure in the 1992 Body Diagnostics Procedure Manual (Publication No. 81-699- 0244)
   3. If ALL of the warning lamps are OFF except for the "Check Gauges" lamp, and NONE of the gauges operate, proceed to the next step.
3. Check the chime, intermittent wipers, and instrument panel illumination for operation.
   1. If NONE of these features are operating, the body controller is locked up. Go to REPAIR PROCEDURE 2.
   2. If ANY of these features are operating, the body controller is not locked up. Refer to the cluster diagnostic procedure in the 1992 Body Diagnostics Procedure Manual (Publication No. 81-699-0244).

ELECTRONIC CLUSTER

1. Verify that one of the conditions exists by turning the ignition switch to the ON position (several OFF-ON ignition cycles may be required), and observing the instrument cluster.
2.  
   1. If NONE of the gauges or warning lamps are operating, refer to the cluster diagnostic procedure in the 1992 Body Diagnostics Procedure Manual (Publication No. 81- 699-0244).
   2. The speedometer, tachometer, and temperature gauges in an electronic cluster are not controlled by the body controller, and are not affected by these conditions. If the "Check Gauges" lamp illuminates and the other gauges (except those previously mentioned) and warning lamps are not functioning, proceed to the next step.
3. Check the chime, intermittent wipers, and instrument panel illumination for operation.
   1. If NONE of these features are operating, the body controller is locked up. Go to REPAIR PROCEDURE 2.
   2. If ANY of these features are operating, the body controller is not locked up. Refer to the cluster diagnostic procedure in the 1992 Body Diagnostics Procedure Manual (Publication No. 81-699-0244).

PARTS REQUIRED:

Quantity
Description
Part No.
As Required
Relay
4728987
As Required
Board, Printed Circuit (MPH w/o Tach, cluster 4728413)
4728611
As Required
Board, Printed Circuit (MPH with Tach, cluster 4728418)
4728610

BODY CONTROLLERS ARE SERVICE CENTER EXCHANGE PARTS. CONTACT YOUR LOCAL HUNTSVILLE FEATURE PRODUCT SERVICE CENTER TO ORDER AN EXCHANGE BODY CONTROLLER.
Quantity
Description
Part No.
As Required
Controller, Body (W/ Mechanical Cluster)
4728591
As Required
Controller, Body (W/ Electronic Cluster)
4728597

REPAIR PROCEDURE 1:
This procedure involves replacing the instrument cluster printed circuit board.

1. Replace the instrument cluster printed circuit board as outlined on page 8E-6 of the 1992 Front Wheel Drive/All Wheel Drive Van/Wagon Service Manual (Publication No. 81-370-2105).
2. Verify that the instrument cluster is now operational.

REPAIR PROCEDURE 2:
This procedure involves replacing the relays or the body controller as necessary.

1. Remove the lower steering column cover to gain access to the relay bank and the body controller.
2. Inspect all relays (up to eight) for part number PN 4671001. Replace all suspect relays with PN 4728987.
3. If one or both of the following conditions exist, replace the body controller with an exchange unit, as outlined on page 8E-16 of the 1992 Front Wheel Drive/All Wheel Drive Van/Wagon Service Manual (Publication No. 81-370-2105).
   1. No relays with PN 4671001 found.
   2. The customer reports getting a static electricity shock (ESD) from the vehicle. (Replacing the body controller will eliminate the body controller lock up condition. A new body controller will not eliminate the ESD condition which is found on many types of vehicles and is considered normal.)
4. Verify that all body controller functions are operating. These functions include instrument cluster gauges, chimes, intermittent wipers, power door locks, illuminated entry, instrument panel illumination, and warning lamps.
5. Disconnect and reconnect the battery negative cable.
6. Using the DRB II enter the Body Controller Menu and select "READ FAULTS". Check for any body controller diagnostic trouble codes (fault codes).
7. If the DRB II reads "EEPROM CHECKSUM ERROR", replace the body controller with an exchange unit. Reference the 1992 Body Diagnostics Procedure Manual (Publication No. 81-699-0244) for any other diagnostic trouble codes.
8. If the DRB II reads "NO FAULTS DETECTED", the repair procedure is complete.

 

Which means you need a scanner to perform numbers 6 and 7.