Hi Gene, A bad 4WD actuator will prevent your vehicle from switching from two-wheel to four-wheel drive. In most cases, the PCM will detect the problem and log a diagnostic trouble code. We highly recommend having the vehicle diagnosed by a certified mechanic to determine what part needs replacement.

Do a bench test. Google GM 4x4 front axle actuator demo. There is a video stating which prong is positive, negative, and ground to activate.

Check the ground wires connected to the frame straight down by drivers front door. If those are clean and tight, you probably have a bad actuator. Can test with an expensive analyzer, but part is cheap and easy to install (30 mins.)

Unplug it screw it out I’ll get back and hit the switch see if it works you will see it go in and out if I don’t move it’s junk

Hi Johnnie, I'm glad to assist you. This is underneath right next to the differential. I hope this helps, and if you're interested in this actuator, you can click on the link below for direct ordering to take advantage of our ongoing sale and limited stocks. Happy shopping. https://www.carparts.com/4wd-actuator/replacement/rc32400001?can=CPAE1047_CSQA_20220930

Front axle assembly

Hi Joseph, The puck is a related part of this 4WD actuator. it depends if the old one is still usable or you need to have it replaced also.

Compare the length of your old one to the length of your new one from just under the head at the top of the threads, the flat surface it tightens down against. If the new one is shorter you will need to add a spacer or puck. Usually if yours has a the puck it will not fall out of the housing when you take the old one out and they are normaley allways reusable. Also be carefull not to over torque them, they will crack. This direct acting electric actuator will replace the older slow acting thermo actuators, however you will need an added wire kit. Dorman makes a wiring kit. These type are a nice improvement over those old ones; Dennis

I read online that the actuator was usually the problem in getting the 4 wheel drive to work so I ordered one and installed it in my 2010 GMC. seemed like a cheap fix, sadly it did not get my 4WD to work. No the fault of the actuator. My lack of computer knowledge is the problem. Truck runs well with the 4WD.

Hi Carl, I'm pleased to assist you. Upon checking, this is sold as it is. If interested, click on the link below to order at 31% off the regular price while supplies last. I hope this helps. Enjoy shopping at Carparts.com! https://www.carparts.com/4wd-actuator/replacement/rc32400001?can=CPGG4850

I’m not sure what you mean by puck but the actuator is a complete unit that presses on the fork

Hi, Joe. Thank you for reaching out. No, the harness is not sold together with the sensor. You can use the link below to order the sensor while it is on clearance sale. Thank you for choosing CarParts.com. Happy shopping. https://www.carparts.com/4wd-actuator/replacement/rc32400001?can=cpab2020

No it doesn't.