None of the instruments in the cluster work (Gas gauge, speedomot

fuel pump needs replaced

I know that you can't trust the Trailblazer instrument cluster at all. Our 2007 was the biggest mess, but it's the gauge clusters and not the sending units that are defective. There are Good Folks making a Living doing nothing more than rebuilding Trailblazer Instrument Clusters and you can google that. The only way to know for sure is to verify with other means. For example, For MPH on the speedometer simply drive an indicated 60 mph on any Interstate Hwy that has Mile markers and time how long in seconds it takes to get from one marker to the next. 60 seconds means the speedometer is perfect. A temperature gun can tell you if the temp gauge is working right or not. Is your mileage changing or are the gauges giving you bad info? My advice is start at the gauges because they will drive you nuts. I hope that helps you!

Faulty instrument cluster.

Bulbs burnt out behind the instrument cluster.

bad ground some where start by checking and cleaning the battery post

ignition switch

Yes, the gas gauge works with the digital gas information on the cluster. So if your gauge is malfunctioning, your gas info in the digital cluster will be a misreading.

The problem is blown resistors on the instrument panal circut board. the dash needs to be removed and instrument cluster. Resistors are on the circut board. between six and ten..

i had this problem, you have to bring the gas tank down, change the sensor (little black piece) mechanic should know what im talking about and put everything back, my mechanic took 75$ labour for half hour so try to get it for 50

4 resistors on the back of cluster bad get them at radio shack.