Toyota Repair: front automatic locking hubs/95 4 runner, side kick panel, automatic locking hubs

Question
QUESTION: I have a 1993 Toyota 4 runner and the ac bottom stopped working and also the fan will not come on for the ac or heater. the book i have shows that there is 3 different fuses boxes....I cant find any fuse marked ac or heater?can you tell me where to look for the fix to this problem?

ANSWER: There is a "heater" fuse below the right side kick panel,it's on a small relay block with the heater relay.

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QUESTION: I have a new problem....it seens that the front is locked in .The truck is in 2 wheel hi and the front drive shaft is turning all the time...I conpared it with my 93 and they don`t turn unless it is shifted into 4w low or hi.....it looks like the shifting is done with vacumn and also ele plug down there also....can you tell me what to look far as to fixing this problem...I removed the drive shaft for now. It also has bad u joints and was out of blance...........my main concern is the front wheels being locked up and turning all the time when it shows to be in 2 w drive............help Elvin  thanks for the help with the a/c the relay was bad and blowed the fuse also.......

Answer
It uses the ADD (auto disconnect differential) system, the front driveshaft and the axles turn all the time, the front diff is engaged internally by a vacuum actuator which engages a splined shaft providing front wheel drive, when 4x4 is engaged the 4x4 indicator light on the dash should be on, the problem may be the actuator, it can be removed and checked to see if it's working by applying vacuum to the ports.