Technical help needed. 93 center diff lock issue.

[zolo]

Truck is a 1993 FZJ with factory diff lockers, and has NO CDL switch mod or 7 pin mod.

I have searched for a few days trying to find answers to my questions. I understand the system pretty well but I still am having trouble getting this 80 out center of diff lock.
To start it has no lights proving on the dash. The center diff, nor front or rear diff lights will prove out at any time. ABS light works but it does not orrespond as it should with low lock.

Fuse for the center diff is good. When I shift from hi low nothing happens at all no lights and it stays locked wether in high or low. I read to test the dash light I need to jumper the switch on the tcase to test the lights. All the articles I have read state its a simple 2 wire switch. However this switch has 3 wires. Not sure how this is different from other trucks.

Any suggestions or help would be appreiated.

 

[toyotaspeed90]

There should be 2 switches in the transfercase... one that is a 4L indicator, and one that is a CDL locked indicator. Both are 2 wire switches, simple on/off.

They should look like this:

I know one of them (I think the CDL indicator) is on the passenger side and relatively easily accessible....

 

[zolo]

Yeah there are two switches but the front one which is the lock/unlock I assume is a 3 wire on this truck. Hence my confusion.
Not sure if this truck is some how different but its a plan ole 93 FZJ as far as I can tell all stock.

 

[zolo]

Nevermind scratch all that. Two wires..

 

[FZJ80 in KC]

Check this thread too. Nearly identical issue resolved.

CDL + ABS Lights Do Not Illuminate

 

[zolo]

Copy thank you,
I figired out the electrical issue but the truck still drives like the CD is locked. I can feel the viscous coupler slipping when the truck is in nuetral and I operate the CDL motor to lock and unlock. When unlocked I can feel the VC slipping when locked it can tell it is locked hard. If the fluid is low can it cause the VC to operate weird or act like its locked amd not slip as it should?

 

[FZJ80 in KC]

Light on should indicate locked when you shift into low. If no lights coming on when shifting from high to low, that should indicating the center diff is not locking up at all, unless your indicator light is out.

 

[zolo]

Yeah the CD lock switch is bad. I applied power to the lock actuator motor and was able to confirm locked and unlocked. After that I was abke to jump the CDL switch and then the diff lockers worked. So all the actuators work but the switchs for the CD and rear locker are bad. Now in unlocked the viscous coupler is acting liked its locked or binding. The front locker wiring harness is missing completely so I have to track that down. Might have to temove the VC all together.

 

[FZJ80 in KC]

Okay gotcha. Sounds like you are making progress. Quite a few threads from well known mudders saying they just toss the viscous coupler if they go bad, not replace, so probably not a bad idea.

 

[zolo]

One more question. Does this CDL system have a switch to go into lock and a seperate switch to come out of lock? I was able to get the actuator motor unlocked and the truck drove great with the VC working well. Then I cycled Tcase into low and it locked back up and would not come back out. After that I tried to jump the motor again and get it unlocked but the lock actuator motor took a s*** on me right then. Not im back where I started.

So does it have two switches for lock and then unlock??

 

[Brimley]

One more question. Does this CDL system have a switch to go into lock and a seperate switch to come out of lock? I was able to get the actuator motor unlocked and the truck drove great with the VC working well. Then I cycled Tcase into low and it locked back up and would not come back out. After that I tried to jump the motor again and get it unlocked but the lock actuator motor took a s*** on me right then. Not im back where I started.

So does it have two switches for lock and then unlock??

As pointed out above it has a "switch," really a position sensor, to tell it is in 4low with then sends a signal to lock the center diff. The second position sensor lets the system know the center diff is locked which shows on the dash light as locked and then lets the system lock the diffs. Sounds like both could use a cleaning and/or replacement. Search there is a thread with a part-number for beck-arnold unit that is way less than oem.