I have a 2004 Chev Trailblazer and the instrument cluster the back lights work but the instruments don't, the fuses are good, sometimes after driving it for 15 or 20 minutes and shutting it off and restarting it the instruments start working again, when you intially start it the only test light that comes on is the engine light all the other lights don't come on but the back lights work.

Seems that the IPC/BFC ACC fuse is responsible for the instrument gauges not working on your 2004 Pontiac Grand Am 3.8 Liter1. It is possible that the fuse is faulty and needs to be replaced. However, if the fuse is in good condition, there might be an issue with the wiring or the instrument cluster itself. Check the inputs (powers and grounds) going into the cluster with the key on using a voltmeter. Fix/repair wiring as needed or replace the instrument cluster as needed. A qualified mechanic might diagnose this --and a scan tool.

i have the same problem on instrument cluster sometimes its working very well and sometime not. i try different thins i clean the terminals adding more ground and power but the problems always come back. so i change the whole instrument cluster.i recomend to change your instrument cluster

You will have to have the cluster repaired. If you are handy, you can take the cluster out yourself. There a number of vendors on Ebay who repair clusters.

Unfortunately, GM really screwed up the 2003-2006 instrument panels and there have been thousands of problems but not recalls so far. You might want to consider a complete rebuild of your instrument cluster. There are multiple on-line places that you can send your instrument panel into and they will completely rebuild your instrument cluster and replace the dashboard lighting also. Most of them charge in the $200.00 range for this service.

http://gmgaugerepair.com/vehicles/ is just one of the many rebuild services available

General instructions on how to remove your instrument panel - http://circuitboardmedics.com/files/instructional/instrumentclusters/general.pdf

Hello,

This is a very common problem with 03-06 Trailblazer instrument clusters and it is repairable without having to replace the entire cluster.

Check this page for more on the issue and how to get it repaired - Trailblazer Cluster Repair

Thanks,
-Dr

The problem is a bad stepper motor in the instrument cluster, these motors drive all the gauges in the cluster and are none to fail. There are repair services on Ebay that repair the clusters.

Pretty common problem with these. Here's a guide to learn how to fix GM instrument clusters yourself, I used it to fix mine and it worked great.How to guide for Trailblazer instrument cluster repair

There's 9 screws in the plastic piece that surrounds the instrument cluster and the lower knee guard, remove those screws and pull the plastic trim away from the dash, disconnect the switches on the left side as you pull outward. Then there's 4 screws that hold the actual instrument cluster in place, remove those and pull the cluster out, unplug the grey plug in the back of the instrument cluster and your done. You may need to set your parking brake and put your transmission in 1st gear of you have a column shifter model.

For more information on Trailblazer instrument cluster problems visit this page - Trailblazer speedometer fix

First call your dealer. There is a free instrument cluster replacement recall, which may apply for your problem.

Is it the entire instrument cluster or only some of the gauges? Check this page for more about Trailblazer instrument cluster problems - Trailblazer instrument cluster fix