SOLVED - Help troubleshooting 4WD issue for '00 with j-shifter

[Bad Luck]

So, if I do decide to replace the faulty ADD Position Switch, I think I’d need Toyota PN 8422235110

Can anyone confirm the part number and also which switch it is on the photo below? (I'm assuming the ADD Position Switch in on the transfer case, correct me if I'm wrong. If the body was still off the frame, I'd be able to just following the wires...)

The ADD position switch is on the front axle housing by the ADD vacuum actuator if I remember correctly. Let me see if I can find a better picture and part number...

EDIT: Here's the 2000 FSM I reference: Update your browser to use Google Drive, Docs, Sheets, Sites, Slides, and Forms - Google Drive Help Click on section 29 and then SA-26. The ADD switch is in the upper right corner of SA-27

 

[phattyduck]

The 'click' you are/were hearing when you shifted into 4WD is likely the relay that is in the passenger footwell that sends power to the ADD VSV's.

There is a chance that a previous owner shorted out the front ADD switch (there is a factory part that does this on the manual hub Tacomas!).

That would explain everything you experienced.

The ADD position switch is located just to the right of the front diff flange in this picture, gray with two pins. It doesn't have any wiring on it since I hadn't wired up my 4WD swap yet.

From there, there is a short harness that runs up to where the vacuum hard lines mount on the top of the front diff (just below the oil filter in this pic), then a plug that runs to the main engine harness. Check in those areas for shorts or damage. If it is shorted to ground, it would act like the ADD is always engaged.

-Charlie

 

[Bad Luck]

The 'click' you are/were hearing when you shifted into 4WD is likely the relay that is in the passenger footwell that sends power to the ADD VSV's.

There is a chance that a previous owner shorted out the front ADD switch (there is a factory part that does this on the manual hub Tacomas!).

That would explain everything you experienced.

The ADD position switch is located just to the right of the front diff flange in this picture, gray with two pins. It doesn't have any wiring on it since I hadn't wired up my 4WD swap yet.

From there, there is a short harness that runs up to where the vacuum hard lines mount on the top of the front diff (just below the oil filter in this pic), then a plug that runs to the main engine harness. Check in those areas for shorts or damage. If it is shorted to ground, it would act like the ADD is always engaged.

-Charlie

I disagree. If the add switch wiring was shorted to ground then the 4wd light would always be on. The ground path for the 4wd indicator light goes from the indicator to the add position switch to the 4wd position switch to ground.

 

[phattyduck]

I disagree. If the add switch wiring was shorted to ground then the 4wd light would always be on. The ground path for the 4wd indicator light goes from the indicator to the add position switch to the 4wd position switch to ground.

You are right. I was going off of memory...

-Charlie

 

[cl4Rk]

The ADD position switch is on the front axle housing by the ADD vacuum actuator if I remember correctly. Let me see if I can find a better picture and part number...

EDIT: Here's the 2000 FSM I reference: Update your browser to use Google Drive, Docs, Sheets, Sites, Slides, and Forms - Google Drive Help Click on section 29 and then SA-26. The ADD switch is in the upper right corner of SA-27

Perfect!! Thank you

 

[cl4Rk]

Just so there's no confusion down the road for people looking at this thread. The switches numbered in this photo are:

1. Transfer L4 Position Switch
2. Transfer Neutral Position Switch
3. Transfer 4WD Position Switch

(VF2A transfer case)

All three of these switches in the photo seem to work fine for me.

Below is the diagram of the front diff with the ADD Position Switch at the top right of page two as [MENTION=319302]Bad Luck[/MENTION] pointed out. Looks like I'll need a new ADD Position Switch and a gasket (still looking for part numbers)

 

[Bad Luck]

Below is the diagram of the front diff with the ADD Position Switch at the top right of page two as [MENTION=319302]Bad Luck[/MENTION] pointed out. Looks like I'll need a new ADD Position Switch and a gasket (still looking for part numbers)

I had a problem with my ADD position switch when I first bought my 4Runner. I removed the switch and cleaned it out with electronics/contact cleaner while depressing the "button" (it's more of a ball) and was able to get good continuity when depressed and no continuity when released. Might be worth a try if you haven't ordered parts yet and have a multimeter.

 

[JustTroItIn]

Makes sense that the ADD switch in the diff was bad and the click was the relay. Please let us know if you find the front switch was indeed bad when you get around to it.

 

[cl4Rk]

I had a problem with my ADD position switch when I first bought my 4Runner. I removed the switch and cleaned it out with electronics/contact cleaner while depressing the "button" (it's more of a ball) and was able to get good continuity when depressed and no continuity when released. Might be worth a try if you haven't ordered parts yet and have a multimeter.

Great suggestion. I have the tools and supplies, so I’ll try cleaning the switch before replacing.

 

[phattyduck]

Great suggestion. I have the tools and supplies, so I’ll try cleaning the switch before replacing.

That can/does work for the transfer case switches too. And the reverse switch on many manual transmissions...

-Charlie

 

[Romeo1]

I’ve had luck cleaning switches like that in the past also. Just ohm it out to make sure your continuity is still intact.

 

[cl4Rk]

I had a problem with my ADD position switch when I first bought my 4Runner. I removed the switch and cleaned it out with electronics/contact cleaner while depressing the "button" (it's more of a ball) and was able to get good continuity when depressed and no continuity when released. Might be worth a try if you haven't ordered parts yet and have a multimeter.

When you removed your ADD Switch for cleaning:

1. Did you need to replace the gasket? If so, do you happen to have the part number?

2. Did any gear oil drain out, so you had to top it off with a little new oil?


Just wanted to check on these things before removing the switch so I know if I need to get any parts/supplies.

Thanks!

 

[Bad Luck]

When you removed your ADD Switch for cleaning:

1. Did you need to replace the gasket? If so, do you happen to have the part number?

2. Did any gear oil drain out, so you had to top it off with a little new oil?


Just wanted to check on these things before removing the switch so I know if I need to get any parts/supplies.

Thanks!

I didn't replace the gasket and I didn't have any fluid come out when I removed them for cleaning. I did have to remove the transmission crossmember so I could sag the transfer case/transmission down enough to get to one of the position sensors on the transfer case.

 

[cl4Rk]

I just removed the ADD Switch, cleaned it with CRC electronics cleaner, tested it for continuity, and replaced it. I reused the gasket.

Unfortunately I forgot to test it BEFORE cleaning it, so I’ll never know if it was malfunctioning before I cleaned it. But it tested perfectly after I cleaned it. No continuity when the ball was extended/untouched, continuity as soon as I depressed the ball.

I had to remove the rear skid plate to access the switch with an adjustable wrench. Not sure what size the nut is since I didn’t have a socket that fit and there wasn’t really room for a ratchet up in there anyway.

I also cleaned the connector housing.