Dead gauge cluster - 92 Daytona

[bananacharger]

Hi all-- I've a 92 Daytona IROC R/T that has a dead gauge cluster. I've an extra cluster out of another Daytona that I swapped in and it made no difference. The tachometer was dead but now seems to have come back to life, but the speedometer and the fuel, oil, volt and temp gauges are consistently out.
I thought perhaps that the body controller might be at fault; however, my Daytona has had a 2 button Traveler installed and its trip odometer goes up as I drive the car. I thought that they used the same signal; if so, that would seem to mean that the controller and VSS are good-- or am I wrong in that regard? The "check gauges" light doesn't come on; in fact, the only only lights that do come on are ABS and fasten belts symbol. Right now I'm thinking that there's a loose/bad ground somewhere.
Might I be on the right track, or is there something else I should check first? Also, if it's likely a bad ground, is there a common problem area to check before I rip through the whole car? Thanks very much for any advice and suggestions.

[supercrackerbox]

Have you checked your fuses?

[bananacharger]

Hi-- thanks for replying. Yup, the fuse for the cluster is good. I'm going to pull the cluster again and trace the ground-- I suspect that may be where the problem lies.

[bananacharger]

I did find an issue that may have been part of it: the wiring harness that crosses the firewall from the connector and then runs across the passenger side strut tower had come loose from the tower and was rubbing against the power steering pump pulley. It wore through two wires: one red that has 12V all the time and a blue with orange trace wire (this one was held together by single strand). I thought for sure I'd found the problem but after repairing the wires the cluster is still dead, except for the tachometer. I added a pigtail off of the cluster connection ground wire and ran it to a metal frame brace and verified that there was 0 ohms from pin 14 to the frame-- still no difference. The voltage at pin 9 is 11.5V (same as the battery; it hasn't been driven much of late)-- is that too low to make the gauges work? According to the service manual, is the voltage and ground check out OK and the gauges don't work, then the PCB is bad. I haven't checked the connections at the firewall, although it seems unlikely that all the gauge input wires went bad at once.
Question: Is the PCB the entire board that the gauges connect to, or is it the smaller green board with resistors, a few transistors and an IC chip? I've checked continuity from the pins to the traces on the board and they seem to be OK. If the PCB is likely bad (fried by the engine compartment wiring damage?), is there anyone who can repair the thing, or should I try the old re-solder all the connections to see if that would help? Bear in mind that I've two clusters, both worked OK until just recently. Any advice would be appreciated. Thanks again for the help.

[bananacharger]

I got the ground repaired at the connector but the gauges were still inop. This evening I pulled the gauges out of the cluster and checked the voltage and resistance at the pins-- resistance to ground was high so I removed the PCB and re-soldered all the connections, sprayed contact cleaner in the plugs and tried it again. The gauges now work, and the speedometer came back to life after driving a few miles.
Thanks for the suggestions.
Two somewhat related questions for the experts, though: I've got a 140 MPH installed temporarily while the 160 MPH Nippondenso unit is sent out to have its stepping motor-driven odometer repaired. I bought a cluster used for the temporary use of its speedometer, but it had the usual cracked odometer gear. I replaced the gear a while back, but the odometer doesn't work. Any ideas as to why that might be: working speedometer, good odometer gears but no odometer function?
The 2nd issue is that a 2 button Traveler had been installed by a previous owner and spliced into the body controller wiring. When instant MPG is selected, the mileage is "opposite" of what it should be; that is, when decelerating the mileage shows very low (single digits), but when accelerating the display shows very high. In looking at the wiring, it looks like there's just a data bus + and - for inputs. The trip odometer, DTE, ET and other functions seem OK. Any idea as to what might be the issue?
Again, thanks for the help.