4wd Not Working on 98 Limited

[jranger35]

Hello all. My 98 limited refuses to engage the 4wd when the button is pushed. The light doesn't go on, and the 4wd does not engage (in either 4hi or 4low, moving, stopped, reverse, nothing works). Here are the symptoms, I appreciate any help!

1. When the button is pushed the 4wd actuator on the transfer case engages (clunks) and the front driveshaft is locked.

2. With the vehicle on jackstands, the front wheels still rotate independently of each other (the a.d.d. does not engage).

3. I vacuum tested the a.d.d. last night, and could make it engage by switiching the engage/disengage vacuum lines (wheels spinned in opposite directions when rotated, all four wheels rotated forward when in drive) but the 4wd indicator light refused to come on.

4. I switched the vacuum lines back to normal, and I now believe the problem is electrical, not vacuum-related. Some electrical sensor is not telling the a.d.d. engagement solenoid to send a vacuum to the a.d.d. when the button is pushed--I already replaced the a.d.d. solenoids with ones acquired from the local salvage yard.

5. Does anybody have any idea what electrical component might be failing? Or, what is the most common electrical failure in the 4runner's 4wd system and where is it located on the chassis?

Thanks!

 

[4RUNN!N]

Your 4WD Selector Sensor could be dirty or bad. If you have a Haynes repair manual it'll show you how to repair it in Ch. 7C.

 

[RockyMtRunner]

Check this thread

You might check out a recent thread on this problem:

http://www.toyota-4runner.org/showthread.php?s=&threadid=14641

 

[jranger35]

Yeah, I found the problem last night. I don't know what it's called (4wd position switch?) but I'll just briefly state where it is and how to test it for others that might have the same problem in the future.

It's on the 4wd actuator mechanism. Follow the wiring harness from the actuator to the next pigtail you come across. Disconnect the pigtail, use a 1 1/16" boxhead wrench (works even though it's a metric size) to loosen and remove. Some gear oil might leak out, so be prepared. It looks like a spark plug, with a spring actuated plunger on one end.

Use a multimeter to test for continuity (this is described in Haynes manual chapter 8 for the a.d.d. switch--it appears to be the exact same part). When depressed, there should be continuity, when not depressed, there should be none. My switch had no continuity in either setting. I'll grab a new (used) one from the salvage yard next time I'm out, and I'll be wheelin' in this snow in no time!

Thanks for the posts!

 

[984runner808]

Hey sorry new to this forum, but i have a 98 4runner n my wheel drive is also not engaging i did a air test threw the vaccum line and found out tht air is leaking all over the place through the actuator... But before tht happened my indicator light was not turning on.. Other than having to replace my actuator what else would i have to change?