speedo quits and air bag light comes on with bells

I need some professional help here fellas if anyone can help. I am a big ram fan with a couple of half million kilo wreckers in my fleet with no signs of slowing down. I do all of the maint. myself except
injector pump work (their only weakness). Anyway for the last month the speedo on my 99 4x4 cummins has been quiting but at the same moment the air bag light comes on. It is not affected by bumps on the road. As I accelerate it comes and goes even on smooth pavement. I am pretty sure it does not use the rear axle sensor but a front abs pickup since the rear has been broken off for a long time. I though perhaps the dash panel or plugs on the back so I replaced it with no improvement. Actually it is worse now. checked all fuses, unplugged and plugged lots of stuff, scratched my head a lot. It's hard to bill customers when odo no go. Dealer just shakes his head and says I can drop with a million dollar deposit. Has anyone ever heard of such a problem. Or know where I can get access to troubleshooting literature that will actually help. I'm sure theres a connection between the speedo and the bags. When it first started happening I was afraid she was gonna go off in my face but now I'm used to it. Thanks for any help I can get, brian from canada
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snipped-for-privacy@hotmail.com wrote:

Not clear if you tried this yet, but it works on my son's Jeep Cherokee with the same symptoms: Next time it happens push on the upper and lower corners (opposite sides) of the instrument cluster, torquing it slightly. On the Jeep the instrument cluster connectors wear over time and that seems to reseat it.
Jack
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