Problem with a 93 80-series, thanks in advance.

[BIGdaddy]

my dad just picked up a 93 80series with the locker option. it has ABS and does not have the "CDL" button stock

it does, however, have the CDL switch the previous owner installed. The previous owner said, "it already had the wiring there, i just plugged it in"

well, my dad cycled it in and out of CDL and awd a few times in a dirt lot.

The last time he did it, it went in, but did not come out of 4wd-hi...

he also has pulled off the switch to see if he could get the tcase to shift back into AWD mode via the low range lever.

its at ventura 4x4 being looked at, but if they don't have any ideas, what should his next step be?

he's tried the usual reverse, forward, donuts, up on jacks, etc. all while poking at the CDL switch, and is preparing himself to have to put in a new cdl actuator or solonoid (whatever you call whats on the t-case).

 

[adventureduo]

Is it staying locked even in High Range?

If it was my rig... i would go underneath and pull the center diff actuator at the harness plug. Sounds like it might be sticking. Its a ball switch on the front of the t-case.

 

[MoGas]

Check the fuse marked "DIFF" in the fuse panel at the driver's left knee. It should be a 30A at the bottom of the inboard column. If the fuse is blown while in the locked position, the actuator won't actuate but the Center Diff light and ABS light (if equipped) will stay on.

Dave

 

[Mike S]

this is likely an electrics issue, not a part failure.

If you have a Field Service Manual for your Dad's truck, you will have a better life. Trust me. So get the manual and a multimetter, and a test light. Take it one step at a time.

Mike S

 

[BIGdaddy]

good stuff, thanks for the input.

sorry about the poorly worded, and spelled post above, i've edited it a bit to make it a bit more clear.

I sounded like an ESL student in the first iteration..lol.

 

[Brian894x4]

Go to this page:

http://sleeoffroad.com/products/products_switches.htm

At the top, where it lists "Toyota OEM Center Diff Lock Switch", just below the picture is a link to a PDF instructions.

These are the instructions for if you were to swap in a switch for a vehicle that didn't have it, which is what happened your rig before you bought it.

Now...

Notice how the plug normally has a jumper wire, when there's no switch installed? The resolution of the picture is not that great, but what I would do is remove the switch and reinstall that jumper wire in the correct terminal and see if that unlocks the diff. I'm betting the switch itself might be bad.

Plan B....

Most people who do this mod, do what's called a "Pin 7 mod". See here for explaination...

http://sleeoffroad.com/technical/tz_cdl_pin7mod.htm

The idea of this mod is that even if you shift into low range, the center diff lock will not lock up until you push the button.

If this mod is done, moving the shift level back and forth should have no affect on the center diff lock, only what gear range the tranny is in. More than likely the prior owner did this mod as well.

What I would do is reinstall that wire into the plug (hopefully it was just pulled out and set aside, maybe taped up, instead of cut) and then try reshifting the tranny lever and forth to get it to unlock. This assumes that the mechanism is just sticky or there's a problem other than the dash switch itself.

It could also be that the above wire might have shorted out or that you don't have the right diff lock plug, or that a fuse was blown.

One more thing, I'd verify that the center diff was actually locked and that its not just the dash light that is stuck on. This is pretty easy to find out, because as you turn, the running gear will start to bind up. If it still drives normally, especially on pavement and when making sharp turns, than the diff is most likely unlocked and it's an issue with the signal wire to the dash light or something related.

Hope this helps, good luck.

 

[BIGdaddy]

thought i would conclude this thread on a happy note.

all electrics were checked by ventura 4x4, and a few loose wires were resoldered to 100% condition. the actuator was determined to have power and a good ground through the two relays that lead to it.

problem not solved.

as such, all arrows pointed to the actuator.

the mechanic then dropped the tcase to pull the 4wd actuator and sure enought the actuator was covered in crud, which made the electrical contacts inside useless.

The unit's surfaces and interior were cleaned, polished, buffed and waxed(hehe just kidding on the wax part) and it was reassembled and reinstalled.

problem fixed. :REOutArchery02:

the shop cycled the unit 10 or so times and called it good to go.

my dad has taken it on a trip since, and has cycled it himself about 25-30 times.

no problems at all, and it works WAY better than before according to him. (faster to engage/disengage, smoother, quieter, etc.)

there you have it. thanks for all the suggestions, all of them were relayed and checked by our mechanic one by one. (most of which i he was aware of and were on his "to do" list)

only ended up costing a couple hundred bucks in labor, too. nice!

 

[Hltoppr]

Quite a few of these issues occur in the 80 series, especially if the PO never engaged the CDL or axle lockers....they kinda tend to stick....

-H-

 

[BIGdaddy]

Quite a few of these issues occur in the 80 series, especially if the PO never engaged the CDL or axle lockers....they kinda tend to stick....

-H-

that turns out to be exactly the case. this was a DD for the previous owner, not an offroad rig.

mechanic asked that very question before he started, "was this used offroad much?...doesn't look like it..."