My 92 gmc jimmy 4x4 doesn't work. the light turns on indicating that its on but it stays in two wheel drive i also here a clicking noise but nothing happens

Sorry would need a play and a drive so ask a local mechanic to have a look for you ,could be simple or a complicated thing like a drive shaft broke

4X4

On these issue, there are few solved help links for troubleshooting the issue easily.-------

Click the link below: ---

No 4x4 light on dash?

http://repairhelpcenter.blogspot.com/2011/12/no-4x4-light-on-dash.html

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4X4 Truck makes roaring noise in the front end?

http://schematicsdiagram.blogspot.com/2012/01/4x4-truck-makes-roaring-noise-in-front.html

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Car will not go into 4WD high or 4WD low?

http://schematicsdiagram.blogspot.com/2011/12/car-will-not-go-into-4wd-high-or-4wd.html

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No 4x4 light on dash?

http://repairhelpcenter.blogspot.com/2011/12/no-4x4-light-on-dash.html

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4 wheel drive system will not disengage?

http://technoanswers.blogspot.com/2012/01/4-wheel-drive-system-will-not-disengage.html

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4WD light is flashing and beeping? NO 4WD high?

http://schematicsdiagram.blogspot.in/2012/02/4wd-light-is-flashing-and-beeping-no.html

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2002 Jeep Wrangler: 4WD Idiot Light is ON?

http://technoanswers.blogspot.in/2012/06/2002-jeep-wrangler-4wd-idiot-light-is.html

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Traction control switch will not engage on 4WD High or Low

http://whoisbyme.blogspot.com/2012/10/traction-control-switch-will-not-engage.html

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4WD light flashing and 4WD will engage after few minutes

http://repairhelpcenter.blogspot.com/2012/10/4wd-light-flashing-and-4wd-will-engage.html

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2008 Toyota Tundra: 4x4 Wheel Drive Light is Flashing?

http://technoanswers.blogspot.in/2012/05/2008-toyota-tundra-4x4-wheel-drive.html

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4x4 front differential will not engage the axle on ford?

http://technoanswers.blogspot.in/2012/02/4x4-front-differential-will-not-engage.html

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4x4 will not engage on Ford F150?

http://technoanswers.blogspot.in/2012/02/4x4-will-not-engage-on-ford-f150.html

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Dodge Ram 4x4 light keeps flashing

4X4 LOW LIGHT IS FLASHING ON DASH

http://technoanswers.blogspot.in/2012/09/dodge-ram-4x4-light-keeps-flashing.html

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Ford 4x4 front wheels will not engage?

http://technoanswers.blogspot.in/2012/02/ford-4x4-front-wheels-will-not-engage.html

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These details will help.

Thanks.

check fuse and relay to switch if power to switch retest switch new doesnt mean not defective if no power check connections and wiring for damage or breaks

I own a Jimmy and have done quite a bit of 4 wheel drive repair on it.
The first thing i would check is the 4x4 selector switch. I know for a fact that these will throw a service 4x4 code if they are unplugged or shorted. They sell for 50-60$ or you may find one at a local salvage yard for cheaper. Taking this out and checking it only takes a few seconds, just simply pop the switch out of the dash with the edge of your pocket knife. After you get it out theres a few more tabs surrounding the back plate, and this is where the circuit board is located. I would inspect it visually to make sure nothing looks corroded and also take a sniff of it to insure there isn't a burnt smell. If it were the 4x4 actuator the lights would still illuminate on the selector switch, it just wouldn't engage the 4x4. You'r problem is all electrical trust me .

If this vehicle has a smog air pump, it could be the gulp valve. It is likely to make noise on deceleration because it is vacuum controlled. But, can make noise other times also.

I had the same problem with my 99 Jimmy. try to disconnect your battery for about 5 minutes and see what happen. it fixed mine by doing it.

I had a similar problem, only it would not engage. I had my mechanic look at it. He said that there is a pin that when a lever is moved the pin engages the 4x4. My pin sheared off. He replaced it and now it works great.

BAD IGNITION SWITCH

change the selector switch first it is by far the cheapest

Check the vacume line to the accuator for the cable, mine was rotted and busted. Replaced it . it goes under the battery. Problem solved