1998 Tacoma MT not going into 4x4

Hi all, I tried taking my Tacoma out to some sand down near Bakersfield, and I immediately got stuck in the sand

4x4 system isn’t engaging, and the indicator light on the dash isn’t even coming on. I took the truck to a dealer and paid them 205 for a diagnostic, and they gave the truck back saying they couldn’t figure it out unless I paid them another 410 for two more hours.

they said they tested the vacuum pumps manually and were able to get them both started. What do you guys think? Fuse? Relay? ECU?

 

Did they check the switch that is screwed into the side housing, it's sorta up high and quite a reach, partially hidden, need a good light

Unless your truck has electronic stuff for that

 

they didn’t, but they wrote up a thing saying that’s one of the places I could be having a problem. Is that an easy swap? I plan on swapping out the 20a fuse in the cabin before crawling underneath the truck

 

Welcome to the forum!!

Quite possible none of the techs working at that Toyota Dealer never saw a Tacoma that old up close.

When was the last time you engaged the 4x4?

You Have the ADD system?

J shift transfer case or push button 4 high select ?If not engaged on a regular basis things tend to seize.

The truck has vacuum Switching valves not pumps.

 

I think you’re right about that lol they told me they don’t even have the service manual. They told me I have VSV pumps. I just bought the truck a month ago and made the mistake of not checking the 4x4 when I bought it. So this was my first time trying it.

I have the ADD I think because the hubs don’t have the locker knob. It’s the j shift transfer case

 

So I had the same problem about a month ago. Mine ended up being a disconnected wiring connector that runs to the front diff actuator (I got lucky it was so easy).

But I did a bit of reading to help diagnose before I got under the truck and found the disconnected wiring, and saw several others solve this problem with simple things such as:

- Cleaning gunked up actuators on their front diff or t-case
- Using electrical connector cleaner to clean electrical connectors on the T-case

While you're at it, check the fuse in your interior fuse box (lower left portion of the dash below your headlight stalk).

Good luck.

 

Op has the vacuum style ADD not electric .

I shift into 4 high at least once a month if not more often.

 

Was this your first 4x4 ? Making sure that works should always be part of the test drive.

You might have been able to knock some money off the price.

Check for dry rotted vacuum hoses .

The switch for the 4x4 light is in the Actuator on the front differential .

If the Actuator is seized from not being used the light will not go on.

If you have a hand operated vacuum pump many times you can get things loose if you keep working at it.

Without pulling things apart.

 

What year did that change
I am unclear regarding that

 

After 2000 mine still has the vacuum ADD system.

Not saying the Electric Style could not have been swapped in.

The interesting things one finds on older Tacoma`s

 

So when I had the transmission dropped a couple days ago I found that the wires from a blue connector on the top of the transfer case had snapped. I’m fairly certain this is the 4x4 sensor. Could it be the reason the truck won’t go into 4x4?

or is this sensor just to illuminate the dash? I tried pushing the wires back into the connector and putting some superglue on it, but it had no effect, 4x4 still not engaging, and light still doesn’t illuminate on the dash. Should I just swap out the connecter and wiring? Is that possible without replacing the whole wiring transmission harness? The wiring is all bundled together right now.

 

That's the connector switch that was found sketchy on my rig!
It was the first time truck left me stranded luckily only a few miles from homebase and the frigid icy walk
I was sandwiched in a valley during a blizzard event and it was up in all directions, no use of 4wd, no cluster light
311$ was snatched from my pockets

 

wow your story is way scarier than mine. I only got a couple feet off the road when I got one wheel stuck in the sand

Do you happen to have a part number?

 

I shall hunt it down for ya
Assuming 98 and 97 are near exact parts
Doesn't get to near zero degrees in the bay area I bet lol

 

So this is the part I have that’s still intact, transfer switch. What I need is the bit that clips into this, with the wires attached. I can’t figure out what it’s called.

 

It could be part of the wiring harness

I could not locate the bad switch I kept but it did look like your pic