I have a 2004 Tacoma. The four will drive will not engage. Fuses are good still no light. Transfer case is good. Any answers

There are a few potential issues that could be causing your 2004 GMC Envoy SLT to go into 4-low but not 4-high or 2-wheel drive. Some possible causes include:

1. Transfer case issues: The transfer case is responsible for controlling the engagement of the different drive modes. If the transfer case is damaged or malfunctioning, it may not be able to engage 4-high or 2-wheel drive.
2. Shift motor issues: The shift motor is responsible for controlling the engagement of the transfer case. If the shift motor is damaged or malfunctioning, it may not be able to engage 4-high or 2-wheel drive.
3. Vacuum issues: The vacuum system is responsible for controlling the engagement of the transfer case. If there is a problem with the vacuum system, it may not be able to engage 4-high or 2-wheel drive.
4. Wiring issues: The wiring that controls the transfer case and shift motor can become damaged or corroded over time. This can cause the transfer case to not engage 4-high or 2-wheel drive.
5. Control module issues: The control module that controls the transfer case and shift motor can fail. This can cause the transfer case to not engage 4-high or 2-wheel drive.

It's best to diagnose the issue by a professional mechanic, who can perform a proper diagnosis and repair the issue. They will be able to determine the specific cause of the problem and recommend the appropriate repairs.

Take a look at the wiring to the transfer case and the actuation motor it can also be the control module

Check fuse for transfer case. Check electrical connector to transfer case. Listen for transfer case motor running when switch is activated.

In the transfer case is motor make sure that is working

If the light fashes then stops without shifting I suspect the shift encoder motor. 4 low will only shift in nuetral

check the shift solenoid on the tranfer case also check the voltage going to it! make sure theres 12 volts and check the ground also check the fluid level in the transfer case

Check BJB ( aka Battery Junction Box, Engine Compartment fuse panel ) Fuse #17. This is the power to the Transfer Case shift relay, which powers the Shift motor in the Transfer case and power to the magnetic clutch coil ( via the transfer case relay ).

The other fuse to check is the CJB ( aka Central Junction Box, cab fuse panel ) Fuse #23.

If both fuses check good, time to check for power on the connector for the shift relay and the shift motor. The power from BJB Fuse # 17 is the Dark Green w/ Light Green stripe ( this is hot at all times ).
The old school test is to lightly hit the back of the transfer case, to see if the shift motor is hung up.
Here are the diagrams, so you can see what I am talking about.

Sounds like one of your hubs is sticking and not engaging. You can check them by engaging the hubs and the transfer case and jacking up each front wheel independently if it doesn't spin your good, if it does you found your problem. As far as fixing a hub goes, it may be just dry and need some grease, or there are some very good aftermarket hubs available from Warn.
Hope this helps

look at gear oil levels, make sure you don't have to lock out side tire hubs on font center wheels, Another tip is go to the book and look for a transfer case relay, if you have an electric switch, by pass it, hook both with "U" wire or look for fuses or reboot computer, by disconnecting negative on Battery with ignition key ON and engine NOT RUNNING, good luck

If you have auto locking hubs then you need to see if you are getting good vacuum to the front axel and check for a blown fuse or bad accuater