No 4WD Indicator Light

No 4WD indicator on my 1999 Tacoma 2.7L with manual hubs and J shift TC. I pulled the cluster and replaced the bulb and it still hasn't came on. I'm also sure that 4WD is working correctly as it should. Not a huge deal but it would really give me peace of mind at night having the light function correctly. Any thoughts on getting this one resolved?

 

Does your truck have a transfer position indicator switch on the transfer case? If so, and if it's bad, it won't relay to your 4wd ECU that you're in 4WD (even when you are), and therefore the light won't illuminate.

Pulling the transfer position indicator switch from the case is real easy and it should have no continuity when fully released but have continuity when the end of the switch is depressed.

Edit: found a pic of the testing procedure

 

This is very helpful. Is this my switch?

 

I don't think so. Pretty certain that's the actual 4wd actuator. Should be on the driver's side of the Tcase, up high IIRC.

 

do manual hubs have actuators? i thought only ADD had them. I will keep looking on the drivers side

 

The front diff does not (on a manual hub truck), but the Tcase still does. ADD trucks have both a Tcase and diff actuator

 

No, that is the VSS. It's the sensor that tells your speedo how fast you're going.

You need to check your transfer case switches. On top of the transfer case.




Use the info in Jerad's post above to test -
https://www.tacomaworld.com/threads/no-4wd-indicator-light.827378/#post-29660663

 

So what pulled this one from the drivers side and the continuity test was good. Is there multiple ones?

 

There are 3. 2 on the driver side, 1 on the passenger side. I would test the passenger side and the forward switch on the driver side.

 

looks like from the diagram the additional 2, for 4 LO and N, are only on the automatic transmissions

 

yep, my bad.

 

Your "J-shift" case does not have an actuator.
The case has multiple switch locations for various setups/systems.


That being said, the same type of switch is used in many spots from rear locker to front diff. I have seen them test good "on the bench" yet still not work installed. I attribute this to some range of motion difference between pushing the plunger by hand vs what happens when installed.
I have also seen one test bad then good after smacking the plunger a few times.

On another occasion a reverse light switch was testing good on the bench but not when installed. I installed it without the crush washer and this provided a little more "push" on the plunger. It worked fine for a few more years before finally giving it up.

Just something to keep in mind.

 

ahhh. i see now. im an idiot, i had taken out a switch on transmission. I see the 4wd plug now, i only have one on the passenger side. kind of in a bad spot to remove so i put a meter on the ends and it only has continuity in between 2H and 4H. pretty tell tale sign its bad i would assume. now i just got to try to get it out to put a new one in

 

I have determined the switch is bad, but not completly the issue. I put a jumper wire on the ECM connector to "simulate" a closed circuit and still no light. At this point im trying to chase down a wiring diagram for my model, but everyone i see has the ADD and not manual hubs. Anyone know where what circuit this ties to in the ecm so i can check downstream?

 

Did you get this fixed?

I am currently T/S an engagement issue on my 95. I can play with the J shifter and can hear the ECU switching and then 4wd works in 4hi. I believe it's gotta be the switch on the passenger side. I believe it would act up in 4lo also. I am curious if the switch on the passenger side just does all 4WD activity. Is there a light for 4lo and that is where the switch in front on the drivers side is utilized for?

The signal to the ECU I believe sends a signal to swap the vacuum solenoids for the ADD to engage and there is a switch on that actuator also to show it is slid over to lock the axles to the differential.