04 trailblazer speedometer not working occasionally

04 trailblazer 4.2 w/ 42000 miles..shortly after i bought it i noticed the tack didnt always work right, no big deal... but the other day i was going down the highway and looked down and the speedometer was at 40mph(i had been going 70) .i pulled over and shut off engine,and the needle when way below 0.. i started back up and it still didnt work right. i eventually stopped and parked for about 10 minutes,then it started working right again. i have noticed the radio is very hot to the touch also....ANY THOUGHTS, THANKS WOW NOW THIS IS UNREAL. This morning at about 8:25 I faxed the TSB that you are seein below to a friend of mine. About an hour ago he called me to come over to his house and help him fix the same problem you are talkin about because he spent the entire day tryin to figure out the TSB and he couldn’t. I just finished the repair and all is well. I decided to log onto the forum from his house to see what was goin on and I saw your question.

Look man this TSB is real easy. It’s simple and straight forward as a TSB might go but you gotta be familiar with TSB’s and you gotta be patient and know how to follow a TSB step by step. If you’re not used to workin with a TSB then you shouldn’t try to tackle this repair on your own. Goin to a dealer is one option but you gotta understand that a dealer is gonna rape you and then on top of the rape he could end up keepin up your truck for a week or more.

Try to figure out and work with the TSB on your own. It’s not as bad as it looks and it really just looks harder than it actually is. Just go slow and take it step by step. If you got any questions then you can rest assured that you can come back to us 24/7 to get answers. If necessary one of us here will walk you through the entire TSB step by step. The last option you should use is to take your truck to a dealer to have the TSB done.

Good Luck Man
Vito


TSB # 04-08-49-015A: Noise Coming From Instrument Panel Cluster (Replace Instrument Panel Cluster (IPC)) - (Nov 6, 2006)


Subject: Noise Coming From Instrument Panel Cluster (Replace Instrument Panel Cluster (IPC))


Models: 2003-2005 Buick LeSabre

2003-2007 Buick Rendezvous

2004-2005 Buick Rainier

2003-2006 Cadillac Escalade, Escalade ESV, Escalade EXT

2003-2005 Chevrolet Cavalier, Impala, Monte Carlo

2003-2006 Chevrolet Avalanche, Suburban, Tahoe, TrailBlazer EXT

2003-2007 Chevrolet Silverado Classic, TrailBlazer

2003-2007 Chevrolet Kodiak Models

2004-2006 Chevrolet SSR

2003-2006 GMC Envoy XL, Yukon, Yukon XL

2004-2005 GMC Envoy XUV

2004-2007 GMC Envoy

2003-2007 GMC Sierra Classic

2003-2004 Oldsmobile Bravada

2003-2005 Pontiac Aztek, Bonneville, Sunfire

2003-2005 HUMMER H2


Attention: Appropriate repair is based on vehicle build date. Use GMVIS to determine the vehicle build date.

Condition:

Some customers may comment on a noise coming from the instrument panel cluster (IPC) while driving or on initial start-up. Instrument clusters may contain stepper motor gauge. that can make noise during the following conditions:

• Initial startup Car Repair Talk's forum.