Dorman 600-101 4WD Actuator Compatible with Select Models

I have a 1995 Chevy K2500...The thermal actuator went out causing the 4x4 fuse to also blow as a result.After searching through a number of different forums, I found out about the Dorman replacement available here at Amazon.When I ordered the unit, I also purchased the associated wiring harness which is a must have as it also includes a metal spacer that you need to insert into the axle prior to adding the replacement actuator.Removal of the old unit was straight forward, as was installation of the new Dorman unit.The wiring harness plugs right in and there is a single lead that needs to be spliced into a wiring harness running to transfer case.Detailed instructions are provided however when it came to finding the wire/connector that the instructions mention, (4-wire connector C120)it got a little confusing for me as I couldn't locate it on my truck. I went back through the reviews here and found one where the person mentioned that they spliced it into a brown wire that came from the transfer case. I was able to find that wire and spliced into it without any issues, and it provided the power required for the new replacement actuator.The new unit works great, 4x4 is now instantaneous, instead of there being a lag time.Also, it doesn't appear to be effected by temperature at all.And, perhaps the best thing of all, the actuator and the harness cost less then the OEM replacement unit.Win/Win :)Update: 01/10/2023So, almost 10 years to the day this was installed it has failed. Given where we live this isn't a huge surprise, Winter environment where once in 4wd it isn't shifted in or out frequently. I've come to learn through this and other vehicles we own, if you are not activating actuators on a regular basis they just stop working. The fact that this went 10 years (even though the relative miles traveled in that time frame were low) is saying something. I still give it a 5 star review and have reordered.

I ordered this up due to my doubts about the stock thermal actuator on my 94 K1500 Z71.Once it arrived I tested the thermal actuator, and sure enough it was weak!The instalation on this new moterized actuator is pretty simple. Install the spacer that comes in the wiring kit (600-600) and thread/screw in the moterized actuator. Be very careful and sure your threads are lined up as this actuators housing is all plastic.Then just hook up to the wiring connector.Benifits of this moterized actuator over the thermal is, not affected by temps and water, faster, keeps vehicle in 4x4 till you shift out of it (meaning when you turn the truck off you stay in 4x4, where with the thermal when you cut power you go out of 4x4).

The plastic threads are a little hard to deal with, especially when you are installing it in something from the 90s and the linkage it engages with is spring loaded. You have to press down on it firmly and keep it perfectly square to get the threads to engage properly. Other than that, it got the job done right before the bad weather hit. Fits a pretty broad range of GM products

My 1996 Z-71 K1500 would take forever to shift into four-wheel-drive, and if it was cold (i.e. when I needed it in the snow), sometimes it wouldn’t shift at all. The stock thermal actuator is a joke. My truck now shifts in less than one second and stays in four-wheel-drive if I shut it off.I wish this would have been available 19 years ago when I bought the truck for Alaska!The whole job took me about 2 hours and could’ve been less. Would not recommend splicing into the wire as the instructions state. Find a terminal in the convenience center by the emergency brake that has 12 V when the key is on. Mine was the middle pin of the one labeled DRK GRN. Crimped on a red female spade connector and pushed the brown wire onto there. I routed the wire below the oil pan and then up the driver’s side by the brake lines to a hole I already had in the firewall for trailer brakes. Secured everything with zip ties. Super happy now!!

Fits 2006 Silverado Maxx. Works perfect so far. Looks identical to the factory unit i took off. Threads right into the front axle pointing towards the front passenger tire. My truck, for the longest time, would show the service 4x4 message. I could use 4x4 if I immediately engaged once I started the truck, but if it ran for more than 5 minutes then I would get the service 4x4 message. I had an extra selector switch that's on/in the dashboard but wasn't the problem. I changed this part along with the transfer case motor. It was also made by dorman. Now no more error message and my 4x4 option works perfectly. Word is, it's usually the transfer case actuator and not this part, but I've had this truck for years and figured what the heck, might as well do both while I'm down there.

the product worked great and was easy enough to install, much better than the original thermal actuator! the only problem is it failed rather quickly with out any warning, not really what I want if I am stuck somewhere remote in the middle of a Maine winter.