I just purchased a 1999 blazer 4X4 today, and it has a few issues i am trying to work out.
First of all the truck has only 78 000 km(about 48 000 miles) on it and the motor runs beautifully.

First problem, the 4X4 lights flash when pushed( it has the 4 button system)
Second problem The heater blows good heat, but it will not move from the dash position, so i can get no heat on the windshield.

third problem. The brake pedal is really spongy, and the parking brake light stays on.

fourth problem, the power mirror switch doesnt seem to move the mirrors.

Any help would be greatly appreciated. I bought this truck cheap as a second driver, and hopefully can get everything worked out within the next week.

 

The first/second problem is most likely a vacuum line leak.Vacuum not only controls the AC/heat doors but also activates the 4wd.

 

well i went out this morning and found the vacuum leak, i am not sure where it is suppose to plug into but there was an unplugged vacuum line up by the brake booster, so i temporarily plugged it with a bolt to check if it made a difference, and now the 4X4 works, and the heater controls work properly now.

While i was out there i found another problem, its not a biggie to me, but the gear selector on the dash doesnt show what gear you are in.


Thanks for the help so far, i am on my way to check the front brake right now.

 

3rd: your brakes probably need to be bled out. you got air in the lines if you have a spongy brake pedal. on the parking brake the cable is probably rusted and will not disengage all the way, you're going to have to pull the tires and rotors on the back. and lube up the parking brake mechanism, if that doesnt work just disengage it with a screw driver. and from now on out dont use your parking brake. also before you do that check your brake fluid resivoir. its suppose to trip a light if the resivoir is low. if its low you got a leak somewhere.

4th: these are common, the contacts in the switch get corroded. you can either replace the switch. or take it apart and clean the contacts.

 

Before you take the switch apart make sure the MIR/LCK fuse in the underhood fuseblock isn't blown.

 

glad to see you got the heat & 4WD working again.

it's really strange that it wouldn't hit the windshield, since it's supposed to default there if the system loses vacuum, kinda safety issue thing (better to see in the Winter, than have warm toes).

you mentioned your mileage in kilometers, where are you from? (kinda nice if everyone posted they're location info in their bio @ top right corner).

i think Dorman makes aftermarket switches for the 2nd gen's (not sure if the mirror is one of them). got a leaky window? (usually the cause).

 

i am from ingersoll ontario(about 2 hrs from toronto to the west) lol, i will get my location posted up there right away.

Well the fuse was okay so i pulled the switch, and took it apart and cleaned it. half of the switch works now, the other half is dead( i cleaned it twice) so i guess i am in the market for another switch. I took a front tire off as well, the front brakes look just about new, there is no fluid in the front part of the brake fluid resevoir though, so i am thinking i have a leak some place. The back discs i didnt dig into yet because it is so cold outside right now, but they look like they havent been working in quite some time

 

is your rotor nice and shiny or is it rusted

 

they are quite rusty, they dont look grooved or anything, just lots of rust on them.

 

have a buddy push on the brake pedal while you watch the caliper. can you see the piston pushing the pads together and releasing? and on the back are they disc also or drum