I'm looking for the pinout for the wiring harness for a 1992 Town and Country digital dash. It's a grey rectangle, with 6 pins along the top row (3 on each side with a gap in the middle) and 7 pins along the bottom row.

My gauges have been out since February, but two days ago, for one teasingly brief moment, they came back to life.

I'd like to see if the proper signals are actually making it to the dash before I go and get a replacement.

Once I have a pinout, what exactly do I need to check? Going to have to get myself a multimeter.

Are there any relays or anything I could check without having the pinout? Currently, I know there is a fuse in the fuse box near the emergency brake for the gauges, and it is good. If I pull it, I get a repeating triple bing, presumably meaning the dash is not getting power.

 

Ok, the connector is a 14 pin connector, 7 on top, 7 on the bottom. Looking at the terminal end of the connector with the lock on the bottom, the connector numbers 1-7 on the bottom row from right to left and 8-14 on the top from right to left. Pin 1 is unused, pin 2 is pink / Battery feed. Pin 3 is a decode wire. Pin 4 is unused. Pin 5 is another decode wire. Pin 6 is illumination. Pin 7 is ground. Pin 8 is oil pressure switch. Pin 9 is the CCD bus - wire. Pin 10 is the CCD bus + wire. Pin 11 is key on power. Pin 12 and 13 are unused. Pin 14 is illumination ground.

There is a cluste self test. Hold down the trip and trip reset buttons at the same time and turn the key on. the odometer should read CHEC. When it does, press the US/MET button and if there are issues, it should display "CODE" and then flash 3 numbers. Depending on the number is the issue. Try it and let me know if you get anything.

 

I guess I need to clarify a little. I can't actually run the test at the moment because the gauges do not light, so even if the test works, I can't see it. I'd like to actually test the illumination pins to see if they're getting signal.

What voltages should I be checking for, so I don't inadvertently fry anything in the process? Or alternately, could I rig something up to feed the proper voltage to the illumination pins if I remove the instrument cluster to see if it'll light by itself?

Interestingly, the gauges lit up for a second or so on my way to work today, making that two times in the past week they have seen a tiny spark of life after several months of complete deadness.

Just to clarify, you mean the end with the wires that plugs in to the cluster and not the socket on the cluster itself, correct? Again, don't want to fry something by mistake (or on purpose either!).

 

The connector is the part that plugs into the cluster. You want to look at the side of the connector that plugs into the cluster, not the side the wires come out of. the illumination pin is for the back lighting. Has nothing to do with the gauges themselves lighting up. If you do the self test and nothing lights up, Check pin 2 for 12 volts and and pin 11 for 12 volts with the key on. Make sure the ground on pin 7 is good and if so, your cluster is junk. Pretty easy.

 

Dang. 12.2V on both 12V pins, connected to ground. The trip, rest, and US/M buttons do light up, so power is going through the cluster at some point, but the gear shift doesn't light and nothing out of the digital gauges.

All the resistors and diodes tested out okay as far as I could tell. I'd have it fixed if it didn't cost 5 times as much as a used one. Looks like I'll have to order one from a junkyard.

 

Check on ebay for cluster repair. I had my Tahoe cluster repair for less then $100.00 including S&H.

 

Sadly, no eBay repair for my particular cluster. Found a few places that will do it, but the prices are about five times what a used one costs.

That being said, I ordered one from a junk yard. Popped it in today and it works... for now. It seems to randomly make an electrical whine when the van is off, which means it has a part that's probably ill. I'll have to check it in the dark tonight to see if it has the tell-tale red horizontal lines.

On the plus side, I tested my old cluster parts with the "new" cluster parts. My old front circuit board (the part with the display readout) works just fine, so something on the rear circuit board is what crapped out. That makes it easier to track down the problem if I need to somewhere down the road (car pun!). The rear board is mainly resistors, capacitors, diodes, and transistors. The logic chips are mostly (all?) located on the front board.

Unfortunately, the rear board in the "new" one is also the one where the whine comes from.

 

I tried this with the new one just for fun. I pressed the button when it said "code" and it said "999". Is that a problem code or does it mean it's all good? It ran through all the other checks after that just fine.

EDIT: Just found my own answer:

Instrument Cluster Diagnostic Codes
• Code 110-Memory Fault In Cluster
• Code 111-Calibration Fault In Cluster
• Code 905-No CCD BUS Messages From Transmission Control Module (TCM)
• Code 920-No CCD Messages From Body Control Module (BCM)
• Code 921-Odometer Fault From BCM
• Code 940-No CCD BUS Messages From Powertrain Control Module (PCM)
• Code 999-End Of Codes