Where is shift actuator located on 1999 Jimmy 1999

DOES THE CAR START AND RUN ARE THERE BLOWN FUSES MAYBE WHAT ABOUT THE 4X4 CONNECTOR IS IT CLEAN ARE THE LINES HOOKED UP TO THE ACTUATORS HERE'S SOME PHOTO'S OF WHAT IS INVOLVED THERES A ACTUATOR VALVE THAT I CAN'T GET A PHOTO

4X4 shift actuator cable connected to vacuum diaphragm under battery

Well from experience 99%. Of the time its not the actuator if it shifts into 4 lo and back to 4 hi. The book really sucks at this diagnosis. And if lights on buttons blink for 2 hi for a bit then stay in 4wd then u have to listen very carefully. When shifting from 4 hi. To 4 low the whine or growling noise from motor is heard. If, when shifting from 4 hi to 2wd this motor noise is heard, then actoator or wiring is the issue. If the time while 2wd light is blinking, ie: its trying to shift, no noise from motor or actuator is heard, then shift module has a burnt output. Now. Before replacing any of the components, if you have a schematic of this system, you would be confused on how any of it elworks even if you are a seasoned professional. I wouldn\'t bother 2 much with it as long as you theory inspect Evey millimeter of all the wires from actuator connector (on transfercase) to where it goes through metal and enters occupant compartment. If all wires look good. Lights in all 3, or 4 if u were lucky in neutral which means error, of the lights work, and if requested position is depressed on switch and motor tries to turn or does and clynks are heard , then actuator position switch is stuck and actuator is needing replaced, as not a serviceable assesembly, and I haven\'t had the ability to tear one apart. But if all lights work and when the selected switch button , example 4 WD, 2 WD or 4 lo, and no motor noise like heard when other shift works, them module is to blame. Now, I am a master mechanic with most experience at a gm dealership, I have fought with this system multiple times, and once I employed this diagnosis it has never failed me again. And the stack of 4wd shift modules in my bottom toolbox dawyer. Most times if won\'t shit at all night be actuator but not likely, 95% of the time when this issue rolled through dealership, it took a module to fix it.

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Check all your vacuum lines. The smaller vacuum hoses tend to get really soft and gummy. They will collapse when vacuum is present. Look for disconnected hoses and T-fittings. The one that causes the most problems is a large diameter hose that attaches to the vacuum actuator which controls the front differential engagement. The actuator is located underneath the battery tray. You will have to remove the battery and the battery tray to gain access to it. I would recommend that you replace all the vacuum hoses with new ones, even if the old ones seem to be ok. I am assuming the blinking light is for the 4hi and not the 4lo.

you might have an actuator out, some of those have a shifter, but a solenoid still has to be actuated

replace the actuater 59.00 at auto zone

hi how are you doing? just had same problem with by gmc i replaced the transfurcase motor and it works fine. the electric motor moves the shifter in your transfurcase from 4hi to 4lo and 2hi.there is only 3 things that operate your 4x4 the switch the motor and the control modgual.

Your transfer case could be locked up. Try pulling the shifter motor (servo) off of the transfer case and manually shifting the vehicle into 4x4. Make sure to block the wheels as it will roll if you shift into neutral. If you cant shift it, you need to have a professional look at the insides of your transfer case.

do the lights work on selector buttons if so check actuator on transfer case may be bad or replace selector switch i just did and my four wheel drive works sometimes

You need to see if the transfer case engagement motor is defective.