Hi guys!
I have read all I can find regarding 4 wheel drive problems - none covering mine how ever, as far as I can see...
(I will, off course, do all the check ups I´ve read when I find time to do it properly)
I had to jump start the car (Blazer 1999 4wd 4 button panel) last week because whe have full winter, very cold!
It turned out to be the battery and the alternator, both shot - had them replaced and now it´s charging and starts like new.
But - directly after the jump start all lamps on the intrument panel went on incl. the "service 4 wd" for a second or two. All went to normal as it seemed and drove home. After the replacement of the battery and the alternator none of the four 4wd buttons light up!? The car is in two wheel drive only, nothing happens when pushing theese buttons....
Checked the vaccum actuator and the bowden cable today. The actuator seemed OK but the cable was stuck due to battery acid (will replace that as well) - cleaned it and oiled it and finally got it to move a bit and when pulling it I could hear a clicking sound from the front axle.
Everything about the 4wd system worked perfectly before the jump start.
Does anyone have a clue reg. the four push button lights?
Please excuse any flaws in my english, I´m swedish....

 

Check the sensor wire for the front cable it might be that it also went under the battery box and was fouled with battery acid and this corrosion caused the lights to stop...with the extra electricity from the donor car it might have fried the wires from that sensor...

 

Finally I think I´ve solved it Last weekend I went under the Blazer to check the vacum hoses and what not.... - nothing wrong there as far as I could see.
Tried to reset the TCCM three times (!) without result....
Then I went for the fuses, checked ALL of them. One shot!! Turned out to be the ATC fuse (20A) in the fuse box under the hood - replaced it and VOILA the lights came back on the 4 button control box on the dash
Started the engine and tried to put it in AWD - shot the fuse again, replaced it did not put it in AWD only shifted between 2Hi and 4Hi which works. So far so good!
I belive that there is some conflict in the electrical system due to the stuck contol cable causing the fuse to blow? I´ll replace the cable as well and hopefully everything will work after that