i just bought a 1999 4x4 lsblazer and i went to put it in 4 wheel and no matter what setting all the little light does is blink. i did what the owners manual said and the yellow light still keeps blinking any ideas

 

Check all the vacuum tubes that are connected between the transfer case, the thing that engages the front axle (it is located under the battery, and all the tubes that are close to the brake booster/cylinder. Just check for any cracks or if one might of fell off. Good luck!

 

Do you have the Auto4wd option on the dash? If not, please check the DIY article on the OBD2 Non-Automatic Transfer Case Diagnosis...

 

yup i have the auto 4wd me and my dad are going to check all the things your said to check this saterday. and ill let you all no. today i got the inside taken care off it was smoked in and just nasty so now it looks alot better and smells alot better to

 

i started working on the truck today i pulled the battery out and the tray. in the motor bay thers this little thing just kind of chilling not conected to anything. theres a pipe missing off it to. would that be why my 4 wheel drive isint working? heres a pic also you can see in the pic they took the pipes off my heater core so i have a new one and i will be buting that in tomorrow.anyidea how much of the dash needs to come out?

 

I was told there is a diode in the switch unit on the dash. If your service 4 wheel drive light comes on 5 minutes after start-up, there is a voltage problem which one of the diodes is bad change the switch unit out and it should work.

 

that light isint on but the service engine soon one is

 

Hmm... I'm not sure what that vacuum solenoid is for... But I do know that you probably have a bad heater core! Atleast there must have been some reason for disconnecting the heater hoses...

 

I noticed on my '99 the same vacuum solenoid you showed in your picture. Mine has both lines connected. One goes towards the drivers side and ends at a "T" which in turn "T"s off another, larger hose which goes presumeably to the intake manifold. The other goes into a protective sleeve and heads under the truck. It was getting dark so I could not follow it but this could go down to the transfer case to engage the 4 wheel drive. Check to see which hose is still connected as in the pic and then try to find the missing hose.

 

update

my heater core is all done and the inside is all put back together and even with 2 new front speakers and a new headunit.

the 4x4 still isint working. i went and bought new vacuum lines that where bad get everything set up right but it still isint working. there is vacume going to the vacuum solenoid. from there to the thing under the battery it works then from the thing under the battery to the bottom of the truck it wont work. my dad said he saw a little motor that goes to the meatball and theres a wire to that that moved to ingage the 4x4 and its not moveing. he tryed to pull it and it still didnt move any ideas?