Cluster problems when i was driving i noticed the instrument cluster wasn't working. the rpm's speedometer, gas gauge, oil gauge , mileage etc.. were all off and not moving and just blacked out. however the aig lights and check engines lights and stuff like that worked fine. headlights and taillights outside of the car were good as well. does anyone know the issue ?

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!

This is one guy's advice: Replace the speedo head, that should take care of the problem."

This site is also interesting because the guy said
General Motors cars had instrument cluster problems from 2003 through 2006. When I researched instrument cluster problems on the Internet what I found raised concerns in me. Many of those vehicles had problems that began with the instrument cluster, but eventually led to the engine refusing to start.
(an electronic instrument cluster, digital instrument panel or digital dash for short, is a set of instrumentation, including the speedometer, that is displayed with a digital readout rather than with the traditional analog gauges. Many refer to it simply as a digital speedometer.)

http://www.instructables.com/id/Erratic-Instrument-Panel-on-GM-Cars/

I didn't see an s15 in that model year, in my database?
If the speedometer works but the tach doesn't, I think something is wrong with instrument cluster?
GM has had a problem with fuel gage sending units. The sending units are not hard wired to instrument cluster, they send signal to pcm, the pcm sends serial data to instrument cluster, telling the cluster the gage settings.
It may be possible to use different size resistors in place of the fuel level sending unit, to see if fuel gage reacts properly to different resistors, if the gage reacts properly, then I think the problem is the fuel gage sending unit.

Check fuses first. Also check all pcm harness connections

I suspect that your sender is malfunctioning. Todays speedometers and RPM is sent from a sensor/sender near the drive shaft. A magnet on the drive shaft is sensed and the revolutions are converted to RPM and speed.

For information see:

http://wiki.answers.com/Q/Speedometer_on_2003_Yukon_XL_doesn%27t_work_most_of_the_time_is_this_a_common_problem_how_much_to_fix_it

this is a common issue. the internals of the instrument panel clusters become defective, and is a sealed unit - the entire cluster must be replaced. this must be performed at the dealer because they need to reprogram the mileage into the new cluster with the GM scantool. you should call your local dealer with your VIN#, some models are covered by a secret / extended / goodwill warranty. if the dealer says no, request the 1800 number to contact gm. good luck!

My gas guage, speed odometer and tempiture does not work
The speed odometre is reading 9999999 what should i do

Hi, this is a pretty common problem on these Silverado instrument clusters. We can help you out with that! Click here to learn more about these Silverado instrument cluster problems: Dr Speedometer Instrument Cluster Repair Speedometer Repair Guage...

Have the computer checked

On the 03-05 Cavalier instrument clusters this is a common problem, it's caused by failing stepper motors on the cluster's circuit board. It can be repaired though, check out this site for more on how to get it fixed - Cavalier instrument cluster repair