Hello guys, I have a 2-door 4wd 97 Tahoe with 180,000miles on a rebuilt engine. When i start my car early in the morning i get a check gauges light while idling. None of the gauges seems to fluctuate erratically. It seems to go away briefly when shifting from P,R,N..etc. I've noticed that it only happens when idling in park, at traffic stops and driving at low speeds(begins flashing until i hit 15mph+). I also have no back up light. Im really stumped on this one

What are all of your gauges showing when you first start up? Especially oil pressure.

Also, do you have a seperate light to indicate charging issues? This could be another cause on top of oil pressure like Mike mentioned.

Started her up this morning and the Oil pressure is at 60, voltage is slightly above 14. my temperature gauge when warmed up is 2 ticks below 210. Tac is showing 650 rpm. I recently swapped out a bad alternator since it wasn't charging my battery. The check gauges light stays on for about 5 minutes while idling. It then begins to flicker as if it was shorting out.

This happen after alternator was replaced, or also before?