[OldTime]

As long as your actuator has 5 pins do the test and see what happens.

 

[USE257@antelope]

Nothing happened - no movement of the actuator. Bad actuator I presume. Now when time permits, probably next week, I'll put a test bulb to connector on end of leads to the front axle actuator to see it it's getting power when commanded. I hope that will suffice as a test procedure

 

[OldTime]

This must be driving you nuts. I reread reply #13 and you stated you had 4 wheel drive which would have been impossible to have without the actuator working no? All I can think of now is to connect the actuator to its harness,while not installed in axle, and observe for movement as an assistant pushes the 4High button - CAREFULL. If no movement then test for power at the harness leads, if power at leads , likely a new actuator is needed. No power would indicate a problem in wiring. Post back your findings when you can.

 

[USE257@antelope]

Already tested. No movement when actuator was removerd and 4wd drive button pushed. Now, just as we both surmise, check for power in the connector at the end of the leads to front axle just to make sure. Right, a couple of weeks ago I did have it in 4WD as described in #13. Another extenuation circumstance, both axles are showing a bit of bearing wear, even some seal seepage/leaking attests to that as does a little visual play. Worse on left than right. Even so, the control system still ought to do what it should. i think I may be chasing an elusive intermittent problem. Hate those!

 

[USE257@antelope]

So I bought a new front axle actuator. Unfortunately I'm working alone again today so have no assistant to push the 4WD Hi button while I watch the new actuator, uninstalled but plugged in. After I push the 4WD Hi button it keeps blinking and went I look under the truck I see that the new actuator is not extended. i'm wondering, is it supposed to remain extended while in 4WD or is it's plunger extended only momentarily?

 

[USE257@antelope]

This must be driving you nuts. I reread reply #13 and you stated you had 4 wheel drive which would have been impossible to have without the actuator working no? All I can think of now is to connect the actuator to its harness,while not installed in axle, and observe for movement as an assistant pushes the 4High button - CAREFULL. If no movement then test for power at the harness leads, if power at leads , likely a new actuator is needed. No power would indicate a problem in wiring. Post back your findings when you can.

Just posting here so you'll get an alert to see what I posted below.

 

[OldTime]

It would be nice if you could get a person to help with testing as you wanted . If that new actuator works in that test you could eliminate it as the problem and that the power to it is working. If you can complete that test and no movement you maybe looking at it not getting power. You need to do some electrical testing before buying another part or two. Check out these two videos from YouTube on the procedures .
GM 4 X4 FRONT ACTUATOR DEMO / MACANIC 21.
CHEVROLET SILVERADO 2500 HD PUSH BUTTON 4 X 4 FIX /DAN SMITH.

One more point. The Colorado is know to have issues with the ground / splice pack connections becoming corroded and causing electrical issues. There are one above each inner fender , look for the black box with a wad of wires going into it.

 

[USE257@antelope]

Thanks for getting back to me. I'm well aware of the Colorado ground problem and worked over the two ground locations you mention right after getting the machine, maybe 18 months ago. Having the blower motor connection burned up when I got it led me to familiarity with the ground problem. I wouldn't have bought the new actuator without more diagnosis pointing to it but I found it on e-bay, new, for about $100 less than a new GM/AC Delco branded part. I just checked out the video you recommended. Good stuff. It's still a mystery why the actuator did nothing when I connected it directly to battery. I still have to try that with the new actuator.

 

[USE257@antelope]

Wish I has a step-by-step diagnosis procedure for testing. I finally got a helper the other day so I could watch my test as the 4X4 buttons on the dash were pushed. No response at the front controller wire end terminals. My old electronic diagnostic code reader shows no codes. I wonder if the newer, more sophisticated and pricy ones might detect the problem.

 

[OldTime]

What your talking about is a pro scan tool , very costly , and it certainly would find your issue. Hopefully you get this solved or you may need to visit a shop to have them diagnose this ordeal.
In the mean time have you ever established having 12 volts at the connector end of the harness to the actuator ? If you do have 12 volts that new actuator would activate. If no volts what supplies power to that harness end ? It may be the 2/4 switch I suspected at first or is it the TCCM ? On the Colorado Fans forum a guy had a similar 4x4 issue and after he followed my tip about the 2/4 switch he had a friend test the switch finding it bad. He is up and running in 4x4 mode now after replacement of that switch. I asked him to post back how that switch was tested but he never replied, which sucks when people don't post resolutions to their problems. I bet this friend access to a pro scan tool. Let us know if you have the 12 volts for sure and look at the TCCM under the seat for obvious signs of corrosion or damage.

 

[USE257@antelope]

I was under there two days ago, while I had an assistant, trying to get the connector off the actuator at the transfer case hoping to do the very thing you're suggesting. I hate those Delphi connectors. Seems like the combination key to unlocking and disconnecting is different on every one. I pulled out the little grey lock out OK, the one that locks the latch, or at lest another stage of the latch. But there was some further secret to unlocking & disconnecting. I didn't have time that day to figure it out. Remember any secrets to unlocking that one?

 

[OldTime]

Save yourself the aggravation and test for voltage at the connection that plugs into the actuator. I don't know how that connector unlocks , sorry. I never had to get in to it to the degree that you have to fix 4x4 operation on my truck. I know I must frustrate the hell out of you but go back and reread post # 18 and try that again.
After reading every post on this forum that described a similar issue that is what I did . It got my truck into 4x4 H with the light still flashing. At that point I was fairly certain that the 2/4 switch was bad but still not 100% sure. I spoke with a buddy of mine that has worked at the same Chevy dealership for over 45 years [ parts dept.] to get his input . After I finished speaking he flat out said it's the switch. Not uncommon he said.
Now , as stated before,I am not a pro but my 2008 is on its 3rd 2/4 switch and you have described , dare I say , an identical problem.
If my truck had that flashing 4x4 light and I tested it as in post #18 and it went into 4x4H I would not hesitate to replace that switch. I say test it again , it's free and simple before you buy testing equipment or parts.

 

[OldTime]

You ever get anywhere with this ?

 

[USE257@antelope]

Thanks for asking. Not yet. As the front axles are: right seeping left leaking with what to seems to be too much radial play, I'm taking it in to my mechanic tomorrow for his check of front axle bearings and seals, replacing as needed. Shocks too, while in there. He's a wrench, hammer. grease. oil/filter, screwdriver guy kind of guy, not electrical. Really he bills himself as transmission service. Unless that miraculously fixes the non-engagement of the front axle, but since the actuator doesn't seem to be responding I don't expect it will, then my next move is going to be to set all 4 corners on blocks and see if the front driveshaft is turning when in both Hi & Lo 4wd, and go from there.

 

[USE257@antelope]

So I had my '04 Colorado into my independent mechanic for front shocks, a tie rod end, replace front axle seals and check those bearings. He reported bearings are good. I mentioned the 4WD front axle engagement problem I'm having but didn't specifically ask him to spend time on it unless he saw something obvious. He said he remembered a Chevy service bulletin from way back that added a spacer to the front axle actuator. He found something like the spacer as he remembered it, put it in, now the front 4WD axle seems to engage OK, but in limited trials yesterday, I had to go F/R a few times to get it to disengage. The 4WD button on the dash stayed blinking even though the axle was engaged.

 

[OldTime]

So the saga continues , sorry about that. At this point I see two options. Change the 2/4 switch , which is pretty easy to do , or have a shop or dealership use a pro scan tool to diagnose . The pro scan tool will 100% diagnose the issue and then you can decide from their findings if you can do the repair or have it done for you. I know , pretty easy for me to spend your money but I'm out of ideas and it must frustrate the hell out of you by now.

 

[USE257@antelope]

I finally found some time and put all 4 corners up on blocks. When I started work, all about the 4wd worked as it should, except the 4Hi and 4Lo button never went to light solid on, they kept blinking. With all 4 off the ground, there was not the problem of disengaging as was experienced with all four on the ground. I thought perhaps the spacer the mechanic put in was too thick, hampering disengagement. He had simply put in a standard #2, 7/16" hex nut, standing vertical on one of the hex sides, between the actuator and the shifter fork plunger. I was surprised to learn that with only 1/4" movement of the shifter fork plunger, engagement begins, and it's fully engaged with another 1/8" movement. When I pushed the 4Hi button with the actuator out of the axle, just hanging on the connector, I never saw the actuator extend. Of course I was working alone and wouldn't have seen if it extended momentarily, but I'm thinking that if all were working as intended, the actuator should have stayed fully extended so long as the 4Hi button was depressed. Right? I even tried this with a new actor. It behaved the same.
There must be an intermittent disconnection somewhere. I checked the ground and cleaned ground points 101 & 103 ar the lower, left rear of the engine block. They looked good, but I cleaned them and applied dielectric grease anyway. A meter shows good continuity from actuator connecter ground terminal to engine block. I attached a thinner spacer to the business end of the actuator and put the thing back together. I get no 4WD engagement at all. Oh, I should mention that the front axle driveshaft was responding as it should, depending on the 4WD button pushed, so the switch at the transfer case must be good. I wiggled an jiggled the leads going to the actuator. Nothing different. I'm thinking it's now time to replace the control button module on the dash.

 

[USE257@antelope]

Found a bit more time. Put in new 4WD dash control switch and another new (twisted the last new on off) front axle actuator, no spacer this time. Nothing but clicking at the transfer case and blinking 4wd hi blinking switch light. It being intermittent, it now seems to be in the middle of one of it's "I ain't gonna work" modes. I guess as winter approaches and this gets to be higher priority, I'll take to to some shop that has one of the high $, hi-tech code readers and see what I can learn.

 

[Lombardoziii]

I don't think it's the actuator, which is the first thing most people seem to blame. Strange that I don't recall anyone posting back that after replacing the actuator the problem was fixed.Your issue sounds like a failed 2/4 transfer case switch.

I bought a new transfer case motor that didn’t work I bought the transfer case 2/4 shift sensor thing part # 98181804 didn’t work I’ve checked the tccm looks good no indication of it wet or burned out. The only things that I can think of now is the actuator on front left axle and the other sensor on t case that connects on top I believe it’s the neutral position one. Fuses are good and checked any ideas?

 

[USE257@antelope]

I've about run out of ideas. As stated above, I guess as winter approaches and this gets to be higher priority, I'll take to to some shop that has one of the high $, hi-tech code readers and see what I can learn.