I have a 2000 ford f-150 4 wheel drive that will not disengage , I am down here in south fla where and don't put it in 4 wheel drive much , but yesterday I put in 4 wheel drive and I heard the click click and it engaged I put it in drive and drove it about 5-10 miles parked it and turned the switch to 2 wheel high and got out , got back in the truck turn her back on and the 4 by 4 lamp came one went off then came back on and stayed on and it still in 4 wheel drive and wont disengage , HELP ,and I did search the form

 

two things happen when you put it in 4 x 4.. Electric motor on the transfer case engages the front drive shaft toward the axle... and a vacuum cylinder on the front axle engages the differential internal to the drive shaft. That drives the half shafts to each wheel. If the light stays on, then the electic motor might have stuck / failed/ wire came off. THe vacuum cylinder should have pulled the front differential out of lockup. You should have 2 lights... one HO_LO and the other 4 x 4... Is one light off ? Are you sure its stuck in 4 x 4 or just the light is on ? Jack up one front tire and try to turn it. If axle is engaged it will not turn.

 

you might crawl under the front end and look at the vacuum cylinder on the differential. It can get rusty / dirty / sticky.. maybe it needs sprayed with penetrant and smacked with a hammer or pry bar..... it is behind the sheetmetal cover.

 

the light is on and its 4x4 I smacked the elec motor on the transfer case I looked under the front and found the vacuum engage and the rod is all the way extended out and the light is still on

 

Just to help out here, you have to listen to how the system works.
Hitting the case motor does not fix anything even if it did cause the motor to reverse for some reason you would still have the possibility of it sticking again..
Nothing will disengage until the case motor returns back to normal.
This motor is a 12 volt DC motor therefore needs 'reverse polarity' applied from a control relay via the GEM module to make it turn in reverse.
First thing is to remove the connector and re inset it to be sure contacts are made in the connector are not corroded.
Next is to take the motor down and see if it is stuck mechanically in the first position.
The motor rotates a shaft to engage the transfer case to drive the front shaft as well as move rotating contacts on a circuit board that control the fire wall relays.
At this time you can turn the rod back to normal, re align the motor to it's rest position and remount to get use of the truck again.
Doing this will drop out the front drive hardware or it should assuming no other issues when the motor is started to generate vacuum to pull the front actuator out of engagement..
Then begin to trouble shoot when you can spend the time, now knowing how it works and how to get out of a lockup condition.
There is no quick fixes on an involved system operation..

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