I’ve had some issues in the last couple of months with my tachometer not working correctly. Sometimes it will work, most of the time it is way over or under actual RPMs. I figured it was a bad stepper motor or soldering, and had been wanting to replace the cluster with one with trans temp gauge included. So, I ordered a refurbished one from a reputable company that rebuilds clusters to spec. Anyway, I received the new one and installed it. What do you know, the tach is still not working correctly. It seems to work okay for about two minutes at idle, but as soon as I drive it, the needle drops down to 0 and doesn’t move much. I pulled my fuse block under the hood to see if there was any cuts/cracks in the wires, and I didn’t see anything. I’ve searched the internet for several days looking for anything about this issue, but most of them attribute tachometer issues to the cluster stepper motors, bad car alarm installs, or faulty/tired soldering on cluster circuit board. I’m the second owner (my mother was the first), and I’ve not had any alarm, remote start, or anything else tapping into factory wiring. The car is basically in mint condition. Any suggestions would be very much appreciated! Thanks!
2006 Tahoe New Cluster Tachometer Issues
- Thread starter 06Fathoe
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- gauge cluster pcm tachometer wiring
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Same issue here but it’s the tach and gas gauge. I look at that one a bit more often so I’m following this thread to see if there are any suggestions. My first check will be fuses and then ground connections.
You can compare both the tach speed and the fuel level with a scanner that reads what the sensors are reporting.
Welcome to the forum @Stbatch and I hope you are not a fly by new member like @06Fathoe was. He had a problem and did not ask for more help later or post what the repair was if it got fixed and now is "Gone With The Wind".
Anyway, like @Fless said, the correct scanner can check for you. These rigs are known for ground problems. Care to share what rig info you have? If you want to go with a new dash cluster, and get the trans temp added on, use Digital Dash Solutions and never look back. Whichever way you go/do please post results here.
Anyway, like @Fless said, the correct scanner can check for you. These rigs are known for ground problems. Care to share what rig info you have? If you want to go with a new dash cluster, and get the trans temp added on, use Digital Dash Solutions and never look back. Whichever way you go/do please post results here.
Hey there @Fless and @OR VietVet glad to be here…
I’m in the 04 SLT w/ 4.8L for about a month now. Turns out I need to solve some other issues first before being able to diagnose this issue properly.
Engine light has been on and off (I procrastinate until it hurts). Well it hurt me today because it stalled on the wife and kids while getting on the highway. Started back up and not fuel or air so something electrical. Took it for a scan and there was no power to the scanner. That fuse was already blown (looked rusted actually). Replacement 15A fuse was already used (hmm, seems like not the first time it’s had issues). Will be back for another trip to the scanner with a new fuse and we’ll see…
I’m in the 04 SLT w/ 4.8L for about a month now. Turns out I need to solve some other issues first before being able to diagnose this issue properly.
Engine light has been on and off (I procrastinate until it hurts). Well it hurt me today because it stalled on the wife and kids while getting on the highway. Started back up and not fuel or air so something electrical. Took it for a scan and there was no power to the scanner. That fuse was already blown (looked rusted actually). Replacement 15A fuse was already used (hmm, seems like not the first time it’s had issues). Will be back for another trip to the scanner with a new fuse and we’ll see…
Yea, we need some codes or you have to pull parts off and post pics but I would get a fuel pressure reading. You can rent tools from parts stores or use free with a deposit.
rockola1971
Full Access Member
Cluster is likely a bad solder joint or stepper motor in the cluster. But to be sure I would find someone with a K chassis to stick your cluster in and see if it acts up in their vehicle. If it does then its the cluster with solder or stepper motor problems. If it doesnt then it is something in your electrical wiring of your vehicle.
Yep, two issues…
First is code is P0300 random misfire. Good call on the fuel pressure reading, going to start there since plugs/wires were replaced recently.
From what I can tell, the second issue is either a bad body ground connection or in the cluster like you mentioned @rockola1971. Seems like a common issue with this generation from what all I’m reading. It’s not even consistent where the needles start/stop. I added a pic here - it would be funny if it wasn’t my own, so here you go… gas gauge is now vertical down… looks like this cluster wants to be in an EV .
I may try inspecting/repairing the board/components before replacing the cluster entirely as I work with some folks who used to design those things (but not this GMT800 or else I’d know exactly who to complain to!)
More to come…
First is code is P0300 random misfire. Good call on the fuel pressure reading, going to start there since plugs/wires were replaced recently.
From what I can tell, the second issue is either a bad body ground connection or in the cluster like you mentioned @rockola1971. Seems like a common issue with this generation from what all I’m reading. It’s not even consistent where the needles start/stop. I added a pic here - it would be funny if it wasn’t my own, so here you go… gas gauge is now vertical down… looks like this cluster wants to be in an EV .
I may try inspecting/repairing the board/components before replacing the cluster entirely as I work with some folks who used to design those things (but not this GMT800 or else I’d know exactly who to complain to!)
More to come…
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Electrician
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Not sure if you got it solved or not, but it sounds like a wiring issue. Another random cluster most likely isn't gonna have that exact same problem. Ground connection points on these need to be looked at from time to time. But it may not be a ground wire. Do you live in the city or country area? Do you park outside? I've read stories, seen videos, and found evidence in my old truck of rodents. And one of the preferred spots is right underneath the fusebox by the battery. Look at it next time you pop the hood and tell me a mouse wouldn't like that little stow-a-way spot. Thing is: that area has a main artery of wires running thru it from the main fuse box. And most people don't know that the main substance that's in wire insulation is peanut oil. Rat: keen sense of smell and starving for food, insulation apparently holds em over for a while
