I have a 99 Blazer and have been stuck in 4wheel drive for 2 days. problem solved

Could be a problem with the Transfer case control module, (TCCM) or the encoder motor on the transfer case, or a corroded connection somewhere in the circuits. Two common problems are corrosion at the TCCM connector, or a faulty encoder motor. Best to have it checked professionally. 4WD on these vehicles should not be used on dry roads or damage will ocurr. If the transfer case is in 4WD low range, do not exceed 30mph or engine RPM will be excessive and can damage the engine.

When it stayed in 4WD, was it in low range or high range? If it hung up in high range, it's possible that the mechanism that engages the right front wheel got stuck or bound up not allowing the axle to disengage from the differential. Could even be something as simple as the vacuum switch on the transfer case is leaking, which will suck transfer case fluid into the vacuum system causing the actuator to disengage very slowly...or possibly not at all.

Removing the fuses will not disengage 4WD. When the fuses are in, engine running, can you hear any noise from the transfer case when you change from 4LO to 4 HI?