The four wheel drive says its engauge but dont work it a 1985 k5 blazer

Video
https://www.carcarekiosk.com/video/1995_Chevrolet_Blazer_LT_4.3L_V6_(4_Door)/fuse_interior/replace

What fuse does what?

Chevy K5 Blazer & GMC Jimmy (1982-1991) Fuse Box Diagram

https://knigaproavto.ru > shemy > 833-1982-1991-chev...

Fuse Panel Diagram Chevrolet Blazer and GMC Jimmy (K5, K10 & V10; 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991)

ther will probably be a vacuum operated actuator on the shaft to engage the transfer case. Check to see if it has vacuum and is actually working because without it there will be no front wheel drive

does your four wheel light come on if not bad accuator

check all ground leads first ke ep us posted

I would remove and clean the internal parts. They tend to get filled with all kinds of road debry from age and will hang up inside till cleaned and regreased

check your front axle shift motor probably bad.

could be the switch very common problem on those

You have to stop the truck and put it in natural. It should go into 2 wheel drive then. If you have lock outs make sure that they are unlocked.

humming noise come from wheel bearing normally when you go in straith line and you turn just abit on one sid or the other if the noise louder on one side thats a bearing thanks pierre

well. your idle is just high. you can get a screw driver and find the idle screw on the throttle body. . and jsut adjust there , , that is if there are no problems.

now it also maybe a leaky intake. . . . but i think its jsut more of a small adjsutment. . 8)