My 4wd switch worked fine. Right now it is stuck on 4lo ans when I try to switch it to 2hi it just blinks and stays on 4lo with a solid ligbht

In the instrument panel fuse box fuse # 8 CTSY LP 10A ,that's for the dome lights, fuse panel is left side of IP. What are you talking about 4 who drive won't light up or work ? 4 wheel drive ? Do you have two speed automatic or two speed selectable ?
Switch Indicator Lamps Do Not Light - One or More ? Check fuse #15 IP fuse box 10A 4WD . This is for two speed auto !

Circuit Description

The indicator lamps circuits consist of 5 individual lamps contained inside the mode/range switch assembly, they are AUTO, 4WD, 2HI, 4HI, 4LO and NEUTRAL. The AUTO, 4WD, 2HI, 4HI, and 4LO lamps are contained inside their respective range button. When the ignition is ON, the transfer case shift control module illuminates the indicator lamp that corresponds to the current ATC gear position by providing a ground through a current limiting driver.
The transfer case shift control module flashes each indicator lamp after a shift has been requested and will continue to flash until the transfer case shift control module can complete the shift. After a shift to AUTO, 4WD, 2HI, 4HI, or 4LO is made, the transfer case shift control module will flash that indicator lamp until the transfer case shift control module receives a high voltage signal on CKT 1695 from the front axle switch.
A solid state circuit located inside the switch supplies ignition voltage to the lamps. The solid state circuit also receives voltage whenever the headlamp switch is in park or headlamp position. When the solid state circuit receives voltage from the headlamp switch it will reduce the voltage that it supplies to the indicator lamps, dimming the lamps when the headlamps are ON.

THE TRANSFER CASE MOTOR IS ONLY FOR 4WD LOW. That would have never been the problem as soon as you confirmed it shifted into 4wd Low. 2wd and 4 Hi work off of vacuum. You may have one or two issues. A vacuum leak up by the front axle that engages the 4wd HI or the sensors on the transfer case.

Try shifting the transmission into neutral, then transfer case to 2wd.

have you checked if the vacuum actuator is working? this actuator would be found underneath your battery. you will have to take of the battery tray to get to the actuator. if you can find a way to connect the battery, once you've taken off the battery tray and start the vehicle to test the functions on the 4WD switch that would be very helpful. PLEASE BE VERY CAREFUL AND MAKE SURE THAT THERE IS NO WAY THE BATTERY WILL TOUCH THE FAN OR BELT WHEN DOING THIS!! Once you've engaged the 4HI or 4LO, the actuator should be sucked in. when you've set the 2HI, the actuator should be out, to the normal position. Also check to see if the vacuum line is good, most wear with time and tear in other places. hope this helped you. Is your 4WD switch blinking or does it stay on when you change the settings? NOTE that the pic shows the actuator in the normal (out) 2HI position. see pic below to see what the actuator looks like :

check the solenoid on the front differential. i had a similar problem. when i would start to engage 4wd low/high and it would blow the fuse. i replaced the front solenoid and fixed my problem.

the solenoid can be found in the right side of the front differential. costs about $100 at local part store and takes 5-10 to changeout with an adjustable wrench.

Change shift solenoid

I dont know how familar you are with 4wd but have you tried to put it in 2wh and put the truck in reverse for about 15 to 25 feet?Try that and let me know what happens and sounds you hear.Ill also need to know if you have push button or on the floor.

Most common problem is the vacuum diaphragm that is so inconviently mounted UNDER the battery tray.The cable that locks in the front diff is attached to it and vacuum pulls it in/out.

it is either the control switch or the actuator. look if light is flashing on push button switch. if so it is stuck. you can check actuator on front axle, to watch and see if it is moving.

Make sure that all 4 tires have the same tread on them, if one or more of them are different, then the 4wd may not engage. I had the same problem with my blazer, I changed only 2 tires at a time. The front tires would rotate faster than the rear ones, the gears in the transfer case won't line up right.