4WD light not turning on

[4x4mike]

I was messing around the other day on a dirt road and decided to put the 4runner in 4WD. I did and the light did not turn on. I sat at idle for about 30 seconds, went forward and backward and nothing. I then shifted into 4lo and it went in but still no light. Honestly it's been 3-4 months since I last took it out of 2wd but I can't think of anything that could have messed it up. I also am not sure it's just a bulb as the light worked last time and it doesn't get much use.

Is there anything else I could check before I break open the dash? I don't think there is any harm in driving it with a bad bulb, right? Other than accidentially DD in 4wd. The system doesn't require the bulb to be lit, right?

[mastacox]

I then shifted into 4lo and it went in but still no light.

Are you sure you actually shifted into 4wd-lo, or were you just in 2wd-lo? Did you test to see if the front wheels actually had power to them?

If you're not actually shifting into 4wd, you should troubleshoot the vacuum lines in the ADD system. It's possible one of the lines has cracked and is preventing the ADD system from engaging.

[Seanz0rz]

if that was the case wouldnt the light flash?

[mastacox]

I'm not sure if the 4wd light flashes when it's trying to engage, mine is only on or off. But I've never had problems with the ADD system on this 4Runner either.

[L33T35T Tacoma]

Does the light light up when you first turn the key to on? does it normally?

[4x4mike]

To my knowledge the light never turns on when the key in first inserted and the other lights turn on.

I did get stopped up in some rock in 2wd. I shifted to 4hi, went back a little then forward and got out of it. I'm pretty sure that even with a lot of throttle in either direction I wouldn't have been able to get out. I can not verify the same with 4lo and the 2lo comment. I guess I could throw the thing on jack stands and start shifting and gassing it but I'm not sure it would be one of the safeest things I've done.

[Seanz0rz]

while in park, or parking brake set, turn on the truck, shift into 4wd. get under and see if you can turn the dshaft by hand. if you cant that means either the front diff has actuated or the tcase has, or both. now raise the front tires off the ground and see if you can turn one without turning the other. if you cant, that means the whole system is working. if one turns but not the other, it means the front diff is not actuating.

[4x4mike]

Cool, I'll try this when I get home. I did put it in and out at the home depot parking lot and then decided to go in to do my shopping. I went about 200 feet and tried to turn into a parking spot and and I couldn't. The steering was all tight (guess it was still in 4lo) so I stopped (I had already shifted into 2hi), put it in reverse then forward again and was able to park no problem. This makes me believe that the system works but I'll try the driveshaft and lifting the front.

[Seanz0rz]

yeah that would lead me to believe that its working and its simply an indicator problem.

[4x4mike]

That's where I'm at right now but I wanted to make sure that the system would work even if the light was out. Another thing that gets me is why the light is out. It doesn't get a lot of use and I haven't been into the dash to mess it up. If everything works just fine I'll put the light replacement at the bottom of my to do list.


I think Bob has a write up for taking out the instument cluster.