It's hard to know how fast you're going if you speedometer doesn't work, right? Same goes for engine temperature if your temp gauge is out, fuel status is the fuel gauge is out...you get the idea. So it goes without saying that repairing or replacing a bad instrument cluster is kind of a big deal.
If you've already determined that the cluster is bad, this article will walk you thru the process of replacing the whole thing.
Replacing a Bad Cluster
Tools You'll Need
- Masking tape and a pen/marker
- Needle removal tool
- Pry tools
- Replacement stepper motors
- Solder iron (not a soldering gun; it is too hot)
- De-soldering bulb
- Replacement bulbs, if you have bulbs out
- Pop off the trim bezel. There should be no need for tools since most models do not have any screws holding them in place.
- The instrument cluster is held in place with ¼-inch screws. Remove the screws and angle the cluster out. Move the steering wheel or the shifter down if you need room.
- The electrical plug can be disconnected by squeezing the tabs and wiggling the assembly.
- Take the clear plastic lens off the cluster. Use a small tool to pry out the tabs as you pull the lens upward. It is helpful to place something like a pencil between the lens and the cluster as you work around the tabs.
- Rotate the needles counterclockwise until they stop. They should stop at the zero mark or just below it. Put a piece of masking tape on the cluster and use your pen or marker to make a mark just below the top of the needle on the tape. If you do not do this, you will not be able to put the cluster back together because you cannot calibrate it.
- After you have marked all the needles, rotate the needle a few inches further counterclockwise. It will resist the move, so keep your fingers near the base of the needle to avoid damaging the needle.
- Use a needle removal tool or a fork to pry the needle up. Pull straight up and not at an angle. It will come off the motor shaft. Take all the needles off the same way.
- Turn the case over and pry outwards on the tabs. This allows you to lift out the circuit board. You will be able to replace the stepper motors with the board out.
- Take the de-soldering bulb and the solder iron and remove the old solder on the four pins that hold the motor in place. Do NOT overheat, or you will damage the circuit board. When you have the old solder removed, you can pop the motors off the front.
- Put the new stepper motors in place. They only install one way, so you cannot get them mixed up or put them in wrong.
- Solder them in place by putting a little solder on each pin using your soldering iron. It should be a smooth, shiny finish.
- Replace the circuit board into the housing on the cluster and snap it into place.
- Replace the needles onto the motor shaft. Put them on straight down in approximately the 12:00 position.
- Rotate the needles counterclockwise until the needle tip points to the marks you made on the tape. If you miss the marks and it is not noticed until you start up the vehicle, you will need to take the dash apart and start over.
- Replace the clear lens and make sure that the odometer stalk is lined up.
- Reinstall it into the dash by reversing the steps used for removal.
When you replace the motors in the cluster, you may want to check your lightbulbs as well. You can solder new ones in place while you have the cluster apart.
This should fix any problems you are having with your instrument panel, but if you still have trouble, you may need to take the vehicle to the nearest GMC dealership for assistance. Problems like a motor not working after you have installed one can be due to an overheated circuit board and will need professional assistance.