99 blazer STUCK IN 4LO

99 blazer lt, has auto4wd 2hi 4hi 4lo button on the dash.


What happen was... I drove down the street in 2hi, everything normal, I stopped to test the 4wd put it in 4hi, drove down the street, everything normal, I stopped put it in nutrel put it in 4lo, drove down the street, everything normal. Went to take it out of 4lo and its stuck.

I've tried letting it roll and switching. I disconnected the battery . I tried running it threw the gears and switching to knock it loose. I replaced the vacuum actuator under the battery tray.

When I start the truck all the lights come on, on the 4wd buttons for a sec then the 4lo blinks 3-5 times then stays solid. When I hit the 4hi or 2hi (in Nuertal} I hear clicking near the tccm area, I hear the front axel accuator and I hear somthing near the tcase, all while the light 4hi or 2hi light blink but after a few seconds the noices stop it continues in 4lo.

Service 4wd light in not on.

Any ideas what's wrong?

check the electrical connections. i don't know much about 4 wheel, but i seem to recall some people having some corroded connectors, that once cleaned, fixed the problem.

When the 4WD lights blink, they are displaying a trouble code. Watch closely, how many times do they blink?