That plug you show in the pictures looks like the interlock solenoid on the 04 linkage setup. If you are keeping your OEM Transfer Case mounted interlock solenoid then you need to remove it from the 04 linkage. It appears you already have the CDL interlock switch on the Transfer Case and it's plugged in from what I can tell in the pic.

I'd honestly grab an 03/04 SLABS unit (cheap on Ebay) or grab one from Abran, Paul, or Will. Just check the date code on the SLABS unit to make sure you get an 03/04 unit. Then your CDL Light will work like an 04 setup.

The Interlock Solenoid on the 04 linkage setup is held in place with a large C-Clip, remove it, cut the wiring harness, and the Interlock Solenoid can completely be removed from the 04 linkage setup. Then you'll be just like your 99-03 linkage setup with the Interlock Solenoid on the Transfer Case.

 

I have a 2001 SE that was built in Dec 2000 and the CDL was a plug and play. Meaning, I didn't have to mess with the electrical stuff.

Once I installed the shifter, the dash light came on when locked.

 

Mine is a 2000 ( no CDL linkage) and when I crawl under the truck and engage the CDL manually with a 10mm wrench the CDL light on the dash turns on. I don’t think your plug is the problem.

 

 

I agree with Best and with Frank.

I installed an '04 shifter in my '99 DII and removed the interlock switch from the shifter before installing it. Pre-facelift DIIs have the interlock switch mounted in the t-case. The instrument panel CDL indicator operates independently of the interlock switch.

 

 

I made a hybrid 99-03 4hi/N/4lo shifter out of my 04 that I installed on my 99 D2. I completely removed the interlock from the 04 setup, and it looks more like a 99-03 setup with the added CDL linkage.

I've never installed an 04 linkage setup on a 99-02 D2 that didn't require the SLABS to be swapped out for an 03/04 unit. I tried it before I swapped em out and it never activated the CDL Light on the dash. I was lucky to find my first junk yard SLABS for 20.00 and it was dated 06 so it was indeed a rare one. Slapped it into my Kalahari (already had it on hand), and bingo CDL lights up and the dash warning speaker beeps when engaged/disengaged. I later grabbed yet another junk yard SLABS for 20.00 out of an 04 with an 04 date code and I eventually installed it into my 99 D2 when I grabbed an entire 04 linkage setup for 18.00 at a junk yard.

02 Kalahari = I deleted my TC mounted interlock as it failed, and I installed a blank metal plate over the hole and sealed it up (I custom made it to fit exactly like the OEM housing). Then I just simply connected the 04's interlock and called it a day.

99 D2 = TC mounted interlock worked fine so I just removed it from the 04 linkage setup. I also DID NOT re-use rivets to install the shifter plates on either one of my D2's. I used #14 half inch screws so that any future repairs/work are a snap vs drilling out those stupid rivets.