I have a 2000 Blazer, 4.3, and the instrument cluster lights up like the tree on Christmas morning. Performance is not an issue but I've replaced the PCM and the cluster on the advice my mechanic...to no avail. What do I do besides replace my mechanic? Any suggestions?

 

When you say lit up like a christmas tree, what do you mean exactally. Do they flash/blink? Is it when you do specific things?
I had a weird problem with my 94, after I put in a new tail light, a piece of metal broke off the old one, and it shorted out the socket, so every time I turned on my drivers side blinker ALL my outside lights minuse the headlights would flash, and the dash lights would flash like crazy. I just took the bulb out, found the metal connecting the positive and ground, and put the bulb back in and everything was back to normal.

 

When I start the car, the instrument cluster lights stay on. It's the security light, the ABS light, the gas gauge doesn't function BUT the tack and the speedo do function! I don't understand it and obviously, neither does my mechanic!

 

I would say the gas gauge is unrelated. Most likely your fuel level sender is bad. Unfortunately you need to drop the tank to replace it.

Does your ABS kick on at low speeds? Any drivability issues? ABS light staying on could be a bad wheel speed sensor located in the front hub bearing assembly. A good mechanic will have the appropriate diagnostic tools to tell you which sensor is not getting the right voltage, if that's what the problem is.

Security light is most commonly related to the passlock system, but could also have another cause. Do you have any issues with it not starting?

 

Starts fine...drives fine...no braking or other issues. All of the info I've checked states that it's not the VSS because the speedo and the tach both work.

 

I would check the physical wires of the sensors for broken wires, frayed wires, etc.

If nothing comes up then you need to get it scanned with a scan tool capable of reading ABS codes - usually dealer/garage only.

I would also take a look at Kyle's (swartlkk) post on the multi-faceted issues with the ignition switch. A search with the keywords "faulty+ignition+switch" with swartlkk as the author should get you there.