On my 2000 blazer i replaced the multifunction and ignition switches. I did the PASSLOCK relearn. I still have the problem with the speedo, trip, temp, fuel gauge, and the lights for the gear selector are not working. It also still has the high beam indicator on even when the truck is off (it drains the battery over night) and the low fuel light is on im sure thats because the gauge sits on empty. Could these all be caused by a bad dash cluster? Could my headlight switch be bad? The drls and the auto on function have been disabled too the problem was the same before they were disabled. Also i have to unplug the head light relay to turn the head lights off or they will not turn off even when the switch is off. None of the fuses or relays are bad i've checked them all. Any ideas????

 

Same symptoms as before the multifunction & ignition switch replacement?

Have you tried disconnecting the headlight switch?

 

No i havent checked the head light switch ill get back to you on that. yes these problems were there before i changed both switches. Could the problem be in the headlight relays that are in the dash?

Just wondering I have a 2001 blazer also that im parting out (Thanks to an uninsured driver) will the bcm work on my 2000 i know the bcm on my 01 is good.

 

You have to be very careful with BCMs. You will need to match up the RPO codes between the two trucks. You could end up activating the security system. You could have the BCM reprogrammed at a dealer for your truck.

Here is the headlight schematics:

 

ok i found the relay that controls the head lights with my test light i have found 2 wires in the same terminal both green with black tracers have constant power there is a black wire a yellow wire and lightblue wire they do not have power even when the switch is on hopefully in going inthe right direction. this also looks like a relay junction not the bcm or maybe it is im not sure there is a 7mm bolt that holds it together and 10 relays at the top. sorry never had to chase an issue like this