I have a 2001 blazer with the mode overhead console. A few weeks ago, mine was flickering on and off, and finally it just wouldn't go on anymore. I figured it was the unit, so I grabbed 2 of the same units off of junk vehicles at a junkyard but either one doesn't work. Now I know there is a chance it could be all 3 units that are bad, but I just want to check on here for some ideas.I checked the at the harness, and the orange is geting 12v constant, yellow shows no voltage (data wire), 2 dimmer wires show good voltage and dimming when lightsare on, ground works, VSS shows voltage changes when driving, accessory gets power when key is in, temp doesn't show any voltage, and the RAT wire shows 2.5 volts when the key is out before the door is open.

So could it be 3 bad units, or maybe something else causing this?

 

I have a problem similar to that on my 97 that I'm wondering about, It still comes on but there is no more information the MPG Range, Range, Avrg Speed, ect are just a dash now, this happened out of the blew. The compass isn't working either, any info on that? maybe just a bad console? are they easy to replace?