How to replace ignition key in 1997 gmc sierra 2500,,tack and speedo don't work but all other gauges work

First have the computer scanned for trouble codes and as for the gauges first check the fuses and relays then if they are good then you will have to replace the instrument cluster because they are well known for being faulty.

If you are at or near the 100,000 mile mark then your fuel pump may have failed. If you remove the fuel filler cap and listen carefully at the filler neck while someone turns the ignition key to "run" [don't actually crank the engine] you should be able to hear the fuel pump buzz for about a second and a half as the key is turned On. If you don't hear the pump buzz then odds are your pump is dead. Your pump may have actually failed making it appear as though you ran out of fuel. Not to uncommon. Hope this helps and good luck!

depending on what brand and style of gauges you use, you might want power with the key in the start position. I have Autometer electric gagues in my Ford diesel and the power is "on" anytime the key is on or in the start position. If you don't need power during the cranking cycle, then I would probably use the radio fuse.

Your problem is a bad fuel level sensor.The only bad thing is the fuel tank has to come out to replace the sensor.Best time to do this is when the fuel level is low if you have been keeping track of the fuel.Hope this helps.Good luck.

1997 GMC Subburban 1500 loses Tach Speedo and Trans sticks in High Gear. I changed the ignition Starter switch which I read was the problem but problem is intermittant and still exist? AMMCO told me to try changing the Neutral Saftey switch first, but didn't say why?

Hi, your speedometer gauge motor needs replaced, it is wearing out which is very common on these trucks.

I'm a specialist in sierra speedometer repair and can help you out, check out my site at www.DrSpeedometer.com

Have the speed sensor checked on the transmission. I believe that truck has a 4L60E transmission in it. If so, the sensor is on the left rear of the case.

try replacement of the brake light switch

That sounds to me very much like your theft deterrant system has disabled your fuel pump.
On a GM vehicle that is usually brought on by putting anything into the ignition switch other than the correct key. If you are actually using the correct key, then it means that at some other time then something else other than your key was inserted into the switch.

Try disconnecting the battery for a minimum of 30 minutes.

It could be the harness and it could be the ignition key switch.