1987 Digital Dash Question

[jasel]

This posting is in the "Non Specific" forum because I'm sure this is a valid question for makes and years surrounding my 1987 DeVille.

The speedometer flashes at 85 and above. Does anyone know how to disable this "feature?" I am 99.5% positive the "problem" lies with the electronics that drive the dash cluster and not with the BCM. Reason being, I had to replace the BCM a few years back and did so with a junk-yard-special out of an '87 DeVille with an analog cluster instead of digital. Yes, I took the chance, but that assured me the BCMs were the same as I noticed no problems and everything works fine.

The flash-at-85 feature existed with the original BCM as well.

I'm just wondering if anyone knows exactly how to do this, but I'm also open to acute suggestions. I'm sure I could figure it out myself, however, this is my primary vehicle and I can't be driving around without an instrument cluster while the electronics sit in pieces on my workbench hooked up to scopes. I don't even want to THINK what a junk-yard would charge for the entire digital cluster out of another vehicle just so I could use it as a lab rat.

Help would be greatly appreciated.