SOLVED 2000 limited stuck in awd/4wd, multi mode issues. Blinking 4wd lights

[Tinigunner11]

ISSUE IS FIXED!! SEE THE POSTS #5 & #7 BELOW
Hello everyone, I know there are a million and half threads about this topic and I’ve read through all of them. Most of them have dead photo links due to photobucket and the others just dead links in general.

I just picked up a 2000 limited and it ran great minus the trans sounding like it was crushing popcans when in gear, has the multi mode j shift transfer case and it all worked awd, 4hi, and 4lo no problems. That is until I swapped in a new trans... I bought just a transmission out of a 99 and installed it and then put my transfercase onto it. The trans shifts great but as soon as I started the truck the 4x4 lights started flashing and the truck is stuck in awd/4wd. I have the front driveshaft disconnected so I don’t think it has to do with the front diff actuator, but I’ve been wrong before. Any guesses on why it would be stuck all the sudden? And does anyone have access to pictures of how to jumper the actuator with 12v?

I apologize for starting a new thread about this, I’m an engine guy and a total noob when it comes to transmissions and transfer cases.

Edit: I updated to show that this issue has been resolved. I also changed the title so it would come up easier in a google search for future people with a similar issue.

 

[TheDurk]

Here you go...2000 FSM

 

[gmcmanus663]

Not sure if the 00' used the same front actuator as the electric 01'-02's did, but here's a page that helps diagnosing them. My 02' had a 4WD issue and the front actuator ended up being the issue but like I said this is an electric one not vacuum operated like earlier 3rd gens

 

[Tinigunner11]

Here you go...2000 FSM

Thank you so much dirk! I could find that for the 01-02 multi modes but couldn’t for the 99-00. Thank you so much. I’ll update this thread with what I find.

 

[Tinigunner11]

Just wanted to update this thread. I got the chance to dig around in the truck some more. I'm not sure if this was the official issue or if I did it when I unplugged the harness this time but I did find that this plug had a broken wire and it pulled out of its pin in the connector. Anyone know how to repin a plug?? Here are the pictures to follow.

Untitled by austin jenkins, on Flickr
Untitled by austin jenkins, on Flickr
Untitled by austin jenkins, on Flickr
Untitled by austin jenkins, on Flickr

 

[BrianSD_42]

You could just use a crimp and spades to splice the wire for testing purposes. That connector is fairly common and likely at the dealership.

 

[Tinigunner11]

Issue fixed!!

Since so many of these 4wd issue threads don't have a solution posted I would like to update this with my solution. My issue was exactly what is posted above. The wiring harness broke inside of that connector. My guess is that it happened when I did the trans swap, 20 year old wires got brittle. I just pulled the pin out of the connector and soldered it back together. Then when I plugged in everything back in it popped out of 4wd and my lights stopped blinking!

My issue was that the wiring broke inside the plug, I only found it because I noticed that the rubber insert was slightly coming out. If anyone has a similar problem to this in the future be sure and check all of you wiring very throughly. Also please don't do what I did and start replacing parts before troubleshooting and diagnosing. I bought a new transfer case and 4wd Ecu for $300 trying to fix a problem that I ended up fixing for free. I know have a pretty good knowledge of the multi-mode system and lots of wiring diagrams and FSM info on it if anyone is looking. Feel free to PM me and I can send anyone any info I have.

Here are the pictures of where the wiring broke. It would have been almost impossible to see. As you can see this terminal is crimped with a the broken wire inside of it, but it broke clean that you literally cannot see it. Be very thorough it could save you hundreds if not thousands of dollars in the long run.
Untitled by austin jenkins, on Flickr
Untitled by austin jenkins, on Flickr

 

[4thgen619]

Since so many of these 4wd issue threads don't have a solution posted I would like to update this with my solution. My issue was exactly what is posted above. The wiring harness broke inside of that connector. My guess is that it happened when I did the trans swap, 20 year old wires got brittle. I just pulled the pin out of the connector and soldered it back together. Then when I plugged in everything back in it popped out of 4wd and my lights stopped blinking!

My issue was that the wiring broke inside the plug, I only found it because I noticed that the rubber insert was slightly coming out. If anyone has a similar problem to this in the future be sure and check all of you wiring very throughly. Also please don't do what I did and start replacing parts before troubleshooting and diagnosing. I bought a new transfer case and 4wd Ecu for $300 trying to fix a problem that I ended up fixing for free. I know have a pretty good knowledge of the multi-mode system and lots of wiring diagrams and FSM info on it if anyone is looking. Feel free to PM me and I can send anyone any info I have.

Here are the pictures of where the wiring broke. It would have been almost impossible to see. As you can see this terminal is crimped with a the broken wire inside of it, but it broke clean that you literally cannot see it. Be very thorough it could save you hundreds if not thousands of dollars in the long run.
Untitled by austin jenkins, on Flickr
Untitled by austin jenkins, on Flickr

Im having the same issue as you I bought transfer case all the switches new vsv new ecu and still same issue I can now manually put it in 2wd but when I press button n for 4wd it goes straight to 4 locked and it won’t go back to 2wd will check connections.

 

[cyoung13]

This may have just saved me a lot of time. Having the same issue, but it's only happening when it gets down to 30ish degrees, so I assumed it was a bad connection somewhere. Thanks for the info and photos, hopefully this is my issue as well.