4wheel drive not engaging 1993 chevy k2500 fuses are good in dash. 4high only rear posi, 4low engages low range still only rear posi. linkage appears to be working properly, eletronic connectors on trany & front diff. look good. what are the 2 wires that go to front diff?

check linkage, out of adjustment, or worn. Interferance between the control lever and the console. play in transfer case mounts. internal wear.

Check the fuses of the lo and hi 4 wheel drive or disconnect the terminals put them together for ten minutes and reconnect and start and see what happens

NO THERE SHOULD NOT BE ANY NOISE WHEN ENGAGING OR DISENGAGING 4LOW OR 4HIGH

does it have auto hubs, if so check the vacuum switch at tranny side

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It is probably the actuator that locks in the hubs.

The posi is lucky if it ever does anything
It won't lock,the clutches almost alway slip when they are suppost to work

Pull the cover and see if you have broken washers on the side spider gears,etc
On a 93 I would pull the carrier out and put in new clutches and inspect for your issues.

Good Evening. 4high is a simple deal to get working. 4low has a few more steps. First of course is starting the truck, shifting down into neutral at a stop then put it in 4low. After doing so then put it down in drive 4low should now be engaged. And to take it back out of 4low simply reverse the operation. Any other questions let me know, becuase if it can do 4high the shifting motor can do 4low.

it might be the actuator located under the battery tray. look at that and see of it is ripped, torn, or the cable might have came loose.

if the truck has a push button system you may have to go underneathe the truck an see if the connection harness has any breakage or if the harness is not tightly plugged in is the first step if that all checks out try the fuse relay center which should be located in the drivers door jam on the side of the dash when door is open make sure the 4x4 disengage and engage fuse is not blown then the third is pull off the face of the dash and make sure the connector is tight and working in order then do a simple test of the switch with a tester.
if you have the floor shifter then go underneath and see if the linkage could have come unhooked or the wire harness may have come undone the same way. Good Luck

it sound like it is going in to 4low rang but it may only be low 2wheel power brake it a little on dirt if the tires sin in the rear it was only low ranged 2 wheel u can get this by putting it in 4low and unlocking the hubs it may be a hub prob as it is common