Toyotadirtdevil

So when I Google search both part numbers, Google gives me a top listing of a back up light switch and when I compare it to the Toyota switch they look the same.
Also, I have a relay clicking noise in my drivers side kick panel and have been told that there is also a relay for the ADD. Has anyone changed the relay along with the switch?


THIS IS THE BEST THREAD AND NEEDS TO BE STICKYED.

fierohink

Dirt Devil, What year and model runner do you have? There were small changes over the years. I have the wiring diagrams for '99 and '01. My '99 does NOT have a relay, are you sure you aren't hearing the actuator on the transfer case coming thru the floor? IIRC, if there was a relay, it was in the passenger kick panel area. Keep in mind there are 5 or 6 position indication sensors, I think 2 pairs are the same part just in different locations. Any or all of them can fail and if the 4wd ECU doesn't get the right "answer" based on the shifter position it will blink the 4wd lights and not function.

Toyotadirtdevil

My 4runner is a 99 limited. I can here the one on the tcase and the one up front, they are both loud.

t4R_my_life

Ok, first of all thanks to everyone who has contributed to this thread. I would say this is the bible for the 4x4 issue and still helping people after years of the initial post.
I have the same issue on my 99 4runner ltd with rear diff, run 150k miles.
Here is a little background
I got this truck a few months back along with the 4x4 issue and it was in 2WD then.
As per the previous owner, he got it checked and it was a bad T-Case actuator motor. When I got it, the 4x4 light on the console does not come on when I press (in/out) the 4WD switch on the T-Case shifter. The truck would not switch between 2H or 4H but it would go into 4L using the J shifter.
I got a used working T-Case actuator motor from eBay which had 190k miles and replaced mine, but still no 4x4 or the lights. After some trouble shooting I figured out that the 4WD fuse were blown. Replacing it, the lights came back and when I pressed the T-Case button, I heard the click and the truck went into 4x4. The 4WD light started flashing when I changed the switch into 2WD mode and it was stuck in 4WD. The light kept on flashing all the time and no 2WD. Later, I changed both the diff oil, the transfer case oil and also checked the sensor on the front diff which had continuity. I tried tapping the front diff and also the T-Case with a hammer when trying to switch between 2WD and 4WD using the T-Case switch. Nothing fixed the issue. I removed the T-Case actuator once again and jumped the pins 2 and 3 using 12volt and it turned once. After reversing the polarity on the pins, it did not turn.
I put everything back and when I drove the truck, it was now in 2WD, probably because the motor turned once when I jumped it. However, this time it got stuck again in 2WD and would not go into 4WD except for 4L.
My questions are
1.When the pins 2 and 3 are jumped using the 12V power, does it turn until the power is removed? Since mine turned only once and did not turn after changing the polarity, does it mean its a bad actuator?
Please suggest the way to go next. I am planning to test the continuity of both the sensors on the T-Case actuator next.
2.Many people have mentioned to jump the pins 2 and 3 when the motor is connected to the T-Case. But I can hardly see the pins when its up there and how can I jump it? Is there an easy way to follow?

t4R_my_life

Finally, I was able to fix it. I had the actuator motor that I swapped on the rig with the one I got from ebay and was playing around with it. Opened it, cleaned it and jumped it with 12v DC power. Figured out that it does not continuously turn until the power is removed. It turns to a point and then stops, once you change the polarity, it starts to turn in the opp dir. Then I swapped this one with the one on the rig and removed the battery negative to reset the ECU. Connected it back, took it for a spin and tested the different options. 2H - 4H works with the button, 4HL works when the shifter is moved down, 4L works too. That means, all the damn options works ��. Had been dying for this very moment.

Jonahrangerboy

fierohink

TheDurk

You don't have to change them willy-nilly. You can pull them and test them for continuity when the tab is depressed. At 25-$30 apiece swapping them all is sort of painful when likely only one is bad.

Someone who really knows what they are doing can test them in place, but it is not something that can be dealt with in an internet forum.

Bh117

Childrenrn

Hi there,
Will you please email me the information you have?
My email is: childrenrn@aol.com
Thanks a mil,
Vicki

Childrenrn

Hi there,
Will you please email me the information you have?
My email is: childrenrn@aol.com
Thanks a mil,
Vicki

mkaye

my manual 1999 SR5 won't engage the front axle - so no dash light
front axle free spinning when I engage the 4WD
checked vacuum to the VSV with my finger & there appears to be vacuum
reversed the hoses to the ADD - front axle didn't lock and continuity didn't change on switch
how can I further troubleshoot the ADD?

mark

mkaye

I connected the VSV vacuum outputs to the vacuum IN line 1 at a time
switch output didn't change - wasn't able to check if the axle was locked

mark

fierohink

Mark if you have ADD then your hubs are engaged all the time. The disconnect is at the differential, hence (A)utomatic (D)isconnecting (D)ifferential. The locking and unlocking occurs within the front differential, not out at the hubs. If you take the actuator off the front diff you should be able to slide the fork manually with a flat screw driver. This will tell you if the differential fork is stuck, then you should also be able to cycle the actuator with vacuum on a bench test.

mkaye

thanks - going to wait until my mechanic has it up on the hoist
then we'll test the ADD

mark

anyone have the part # for the ADD for my 99? 41400-350xx?

TheDurk

41400-35020. I also have a '99 5-speed SR5. If I understand all you have described, then you have (at least) two problems. If the vacuum does not switch sides at the VSV when you engage the J-shift, then you have either a bad VSV, a bad position switch on the TC, or some other problem not involving the front diff. If the diff does not engasge when vacuum is applied to either front diff hose, that's a diff issue. But sometimes, they can just be picky. If not used recently, some like to be driven forward and backward a little to achieve engagement. So I would fix the truckside issue first, and get that VSV switching sides, before I took apart your diff, based on your symptom set.

Otherwise you may be fixing what ain't broke. We know the VSV/TC side is broke. So I would first see if the 12V+ is switching sides at the VSV. If so, bad VSV, If not, then time to test the switches on the TC. If memory serves, it's the one on the passenger side. In any case, it's the one with the blue wire. If it's blue-red, you're on the wrong side.

TheDurk

41400-35020 is the diff actuator. ADD is the whole system. I also have a '99 5-speed SR5. If I understand all you have described, then you have (at least) two problems. If the vacuum does not switch sides at the VSV when you engage the J-shift, then you have either a bad VSV, a bad position switch on the TC, or some other problem not involving the front diff. If the diff does not engasge when vacuum is applied to either front diff hose, that's a diff issue. But sometimes, these vacuum diffs can just be picky. If not used recently, some like to be driven forward and backward a little to achieve engagement. So I would fix the truckside issue first, and get that VSV switching sides, before I took apart your diff, based on your symptom set.

Otherwise you may be fixing what ain't broke. We know the VSV/TC side is broke. So I would first see if the 12V+ is switching sides. If so, bad VSV, If not, then time to test the switches on the TC. If memory serves, it's the one on the passenger side. In any case, it's the one with the blue wire. If it's blue-red, you're on the wrong side. They are up top by the 4wd shifter and a pain to get to, but it has to be done. Should show continuity when the ball is pressed in. 27mm wrench.

mkaye

thanks for the part # (if I have to go that route)
symptom - no 4WD i.e. front diff not locking, but TC is doing it's thing and no dash indicator

I can't tell if the vacuum is switching - I was using the front diff as my indicator - if locked when switching hoses, then VSV problem, if not, then diff actuator not working
I switched hoses and went down the street, still no 4WD
I probably caused this by not engaging the 4WD on a regular basis, probably been over a year since I used it
I am heading canoeing for 10 days on Friday (don't need 4WD)
can't afford to take it apart & back together before then
I have owned this since new in '99
I am back on the 22nd and not heading to my mechanic until the 28th
i'll have a few days to try more troubleshooting

I started with the drivers wheel elevated
switched hoses - front wheel still turning

front end up on ramps, so I can't check if front wheel still spinning

I disconnected both hoses from the VSV and connected one at a time to the vacuum line feeding the VSV's (bypassing the VSV's completely)
I am assuming that vacuum on 1 side and atmosphere on the other should cause the actuator to switch sides
I was underneath checking the output of the switch - no change
I admit, could be bad switch and diff was locked - too much engine noise to tell if actuator worked - very rusty under there - could be hole in diaphragm
Better way to troubleshoot?
I am trying to find one of my friends with a vacuum tester
I am not a car/truck guy, but know my way around logic and a meter

TheDurk

All you need to tell if the vacuum is switching is a Mark I thumb. Remove each hose in turn from diff at VSV and apply thumb. Repeat with 4wd engaged. Should move from one side to the other.

But now it does sound like you have a diff issue.

I don't like your test of bypassing the VSV to manifold output line (can you output vacuum?) because you also bypass the reservoir, and you're not pulling much vacuum at idle. I like to charge up the system by twisting the throttle plate a few times, engage 4wd on the J-shift, ...and then switch the hoses quickly. That allows strong vacuum from the reservoir to flow to the actuator. Then do the drive back and forth thing. You'll feel it if the frot diff engages even if the switch is broken.

Unlike the fancier models, on our rigs the switch on the front diff just lights the light, it's not needed for mechanical engagement.

fierohink