1997 Dodge Grand Caravan SE 3.3 - Instrument cluster died suddenly (not intermittent).

Previously repaired the solder joints (3 years ago?) which fixed a "intermittent" gauge problem.

Removed the cluster and inspected all solder joints under magnification. No hot spots, no cracked joints. Did have one of the technicians at work re-flow a couple of joints. NO JOY - panel is still dead.

Symptoms:
1) Dash died suddenly - not intermittent
2) Tach and Speedo at max scale. Fuel and Temp jump when ignition switched on, but settle @0.
3) ABS light on and will set MIL lamp if driven.
4) No codes currently (battery disconnected for dash removal).
5) Drivers door lock switch intermittent. Works 100% from FOB.
6) Verified B+, Switched Hot, and grounds to the panel (from schematic below)
7) No PRNDL or Odometer display. Cluster self test does not function.
8) Can't tell if the backlight is functioning (panel lamps). Dimming function does work on the radio and interior lights.
9) All other functions appear to work (wipers, washer, lights, turn signals, etc.).

Looking for a direction to troubleshoot. The panel is receiving power and ground. My schematic below indicates that the CCD bus originates at the
PCM. For some reason, notes on the forum appear to focus on the BCM.

Is there is a way to bench test the panel? I can rig a power/ground setup to check the self test functions if that is possible (no CCD bus connections obviously).

Edit: Checked panel back light functions this PM - panel lamps work fine.

Edit 10-11-14: ABS module under the van was loading the data buss. Disconnected ABS and cluster functions again.

 

Can someone provide a pinout for the connector on the instrument cluster? My Haynes manual has schematics, but the instrument cluster connections are spread over many pages and do not have pin numbers (only wire colors).

My eyesight is terrible. I can test and measure things on the bench with a 10x loop. Not very good when it's in the vehicle.

I really want this problem to be in the wiring harness or connector. If it's the BCM or the panel itself, the van probably won't survive. It's been a good workhorse for 17 years, but $300 to $500 isn't in the cards.

Thanks,
Mike

 

How about $50 from a salvage yard? Tried EBay?

Yes, data bus is controlled and powered by the BCM. PCM is one of several modules on the bus. Could try disconnecting the PCM,TCM, HAVC control panel, overhead display, ABS controller and ORC one at a time and see if the cluster comes alive. They've been known to load the bus and kill it. Besides the cluster connector another hot spot is the HVAC panel connector. It's been known to melt, distort the contacts and open the data bus circuit killing the cluster in the process.

Send me an email address via a private message to keep from broadcasting it and I'll send the diagrams. Same diagram just with the pin numbers.

 

Got the PM. Just sent 2 instrument cluster, 1 computer data and 2 body computer diagrams. Let me know if you need more.

 

Cougar41,

Thank you for the diagrams. Should make things easier with all the connections on the same page and with pin numbers.

Your comment below on the CCD bus - I was under the impression that the panel would run a self test without the CCD connected. Is this incorrect?

Since my scanner connects to the bus with no errors and shows tach, speed, etc. , I was hoping this was a cluster only problem. I know I'm getting the signals to the connector. Not totally sure the connector it making all connections in the socket (next on the list).

I had looked on ebay for the instrument circuit board - these were NOS and expensive. Just looked again for the entire cluster and found 2 within driving distance (head slap).

Thanks again for the help. Will report back if I find the problem.

IM

 

I had similar problems, even the cluster lit up when lights were on, but no gauge movement or signal lights, etc. Had a burnt trace on the circuit board under the Motorola brand chip.

There are some clusters on eBay without the tachometer for under $100. Why need a tach if its an auto?
Has the LCD drive indicator, but make sure the dash connector is the same. Red to red. Black to black. I learned that the hard way, but seller didn't specify.

Like this one.
http://www.ebay.com/itm/A3B1-96-97-9...d7b8c7&vxp=mtr

 

I guess I'm weird but the lack of a tach even with an auto drives me nuts.

 

After receiving Cougar's sage advice on the data buss, I checked the buss voltages at the instrument cluster (pins 9 and 10). No voltage or activity that I could measure.

I then began disconnecting components from the buss (TCM, Radio, Airbag) while watching the data buss voltages. The last one was the ABS controller under the van - BINGO. Corroded connections and a couple of burned pins. Cluster immediately came back to life.

Now I need to figure out how badly I want that ABS controller on line. Likely need to replace the controller and the harness (burned). I'm thinking this just became a non-abs vehicle.

I big thanks to Cougar for the diagrams and advice on the buss loading.