Have the Service 4wd light on, I'm stuck in 4HI. When I turn the ignition to ON (not running) I can hear the shift motor going, and it'll switch to 2wd then back to 4HI immediately. I can see the lights on the shifter **** illuminate as it does this (4HI to 2HI back to 4HI)

Based on my searching, Service 4wd light usually means the FCM has some corrosion or the wiring is wrecked. Any opinions/things I can test before I replace my FCM (fusebox)? My code reader is pulling no codes at all

Connector pin-outs are on pg 1168-1170 for the transfer case in the service manual (Should be the same 02-05)
Any ideas on how I could use the pinouts to test the switches/connectors at the transfercase?

 

Update - Overnight I left the switch on 2wd and it switched back to 2wd. Problem is, we had a blizzard last night. Gonna try my best to keep it in 2wd till I can get fixed! lol

 

Update - Used the 4wd switch once and it did work, but I've also lost cruise control, so I'm thinking it's the FCM. FCM is the fusebox correct? Not the main computer (PCM?)

 

This is correct. It could be corroded underneath. You may also have a bad left front hub sensor. I had a new hub installed under warranty and the sensor that came with the new Mopar hub was bad. My cruise light wouldn't even come on. They replaced it again and I got my cruise back.