4WD Not Working (sometimes)

Hey everybody.
Ive searched and searched again, but I just cannot find the answer.
Ok so, here I go.
I have a 2001 Tacoma 4x4 V6 manual.
Manual (ish) transfer case: 4lo-N-H with the 4WD button on the side.

Sometimes 4wd doesn't work. The light comes on (and stays on) but it just doesn't activate. You can hear the 4wd activating, as there is a slight buzz coming from underneath the truck and it sounds like it's activating. But if I slam on the gas, or sadly: get stuck, you can clearly see that the front tires aren't spinning. The manual says if the light doesn't blink, it should work. Well, the light stays on but there's no way that the front tires are spinning. 4 Hi doesn't work and also 4 Lo.
I've tried activating it while stopped in 1st gear, moving in 1st gear, and stopped in neutral. Nothin.
Now, I'm not mechanic, but I can at least try to fix the problem myself.

Its only worked for me once since bought the truck (only had it for a week or so) but since I'm moving to Colorado, it seems like I'll be needing 4wd around the wintertime.

I appreciate any suggestions or any ideas.
Thank you,
-Tristian

 

Could be a lot of things. I would just jack it up and climb under there and look around. I'm not entirely certain how the 4x4 works on Tacomas but there are a handful of universal truths you can use to trouble-shoot. I would just manually spin shafts on either side of everything you can't see inside and make sure there are no broken components.

The most common breakage occurs in the CV joints so I would start there.

 

Another thing to check is if the ADD actuator is working.

Easiest thing to do is to get it up on jacks and see if the driveshafts are turning and follow the torque out to the wheels to see where it isn't getting applied.

 

Here's an update you guys:

Alright so I swapped the battery in it, and now the truck is super torquey in 4lo and crawls awesomely, so I assumed the problem was electrical and 4wd worked. BUT there is absolutely no power to front wheels at all. I learned that from getting stuck in sand. Again.

I can't really jack it up at my house, but I will eventually somewhere else.

 

A little confused, the 4wd works but no power to front wheels ??... & is the blinking light for the 4wd mode? Mine is either on(engaged)
or off (not engaged)...

 

Is the driveshaft going to front diff spining? If so the transfer case actuator is working and your problem is at the add side of things. If its not spinning (when only rear tires are) then its the transfer case actuator

 

Sorry for the confusion. I ASSUMED 4wd worked. But it doesn't.

 

Ok thanks! I'll try to check it out later today.

 

Try watching this women's video... sounds like your issue, just a sensor that screws into side of tranny??

Malfunctioning 4WD Sensor Toyota 4Runner Part 1

 

On a side note if you cant jack up your truck at home then you really need to get a damn jack to change a tire at the least....

Unless you mean you have no where thats flat/level at your house and you do own some sort of jack?

 

Sadly don't own a jack at all

 

Every new truck sold in America came with a jack.
Was yours missing when you bought it?

 

Yep. I bought it used. I asked if the previous owner if the truck came with one, he said yes so I just took his word. Well, found out later he lied.

 

I have said switch sitting here in my office. Brand new. PM me if you need it

 

Fernando, where can you get this part other than the dealer? Would you happen to know the part number?

Having the same issue with my 2003 Taco. Watch the lady's video, cleaning didn't work. Goona try testing Nd replacing the sensor