Diff Lock lights blink but no ABS light comes on

Joined
Oct 20, 2021
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Minneapolis
I've been researching this site and others trying to figure out my locker issue. I have a 1997, 80 series Cruiser that I bought last year. I've been fixing things here and there as I get time.

When I engage the differential in Low, no lights come on the dash. I try to engage the lockers and the differential lights on the dash flash and I do not hear any clicks or motor noise trying to engage the lockers. If I put it in Low and drive then turn the wheels left and right, the lockers still do not engage. I've pulled the front and rear sensor from the lockers and tested them with an ohmmeter and they both tested fine.

I was looking at this and it says that the ABS light and the Center Diff light should come on after engaging the differential in Low.
Another IH8Mud.com link about the lights

I pulled the dash apart looking for burned bulbs but I don't know if there is a Center Diff light or not with a triple lock cruiser. I do know the ABS light works when you first turn on the key.

Should I have the ABS light and Center Diff light come on when engaging it into Low? If so, what is the cause of that, the sensor or the CDL? I have looked for a replacement sensor and couldn't find one that looked like the right part.
 
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Dec 10, 2007
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The ABS and Diff Lock lights should come on, left lower side of the instrument cluster, when the Center Differential is locked ie: you shift the transfer case lever
into LO. If not there are a few reason, maybe first check the fuse in the fuse box, lower right, but often the issue is due to the switch on the top of the transfer case. Pulling that switch and working it aggressively and cleaning the contacts with contact cleaner and reinstalling might be worth a try.

Try a search for previous discussions.
 
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In a standard non-molested configuration, the front and rear differential lockers will not lock until the center diff is locked.
You must fix the issue with the CDL first. The Toyota factory service manual (FSM) and electronic wiring diagram (EWD) are good places to start. Both can be downloaded from the resources section and give you step by step diagnostics.
 
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Should I have the ABS light and Center Diff light come on when engaging it into Low? If so, what is the cause of that, the sensor or the CDL?

The sensor controls the lights. I verified this last night in a parking lot. My sensor is currently not working, so neither my CDL nor my ABS light come on, even though my CDL is functioning.
 
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Below is the best write up I’ve seen, and I used this and the FSM thoroughly to troubleshoot my 80. The write up is for the FJ80 so some things are different from the FZJ80 but overall it helped me tremendously.


Check to see if CDL is locked by turning a tight circle on dirt, CDL locked will give resistance and drag tires, unlocked will turn smooth.

I had this issue on my ‘96 FZJ80, I tested in a dirt lot by engaging Low Range, and definitely had the CDL engaged, but the indicator light would stay blinking. My CDL would engage but the L4 and or the 4wd indicator switch (located on top of transfer case) was malfunctioning and would not send the “closed” signal to the relay. I believe the L4 switch tells the actuator to close and the 4wd indicator switch sends a solid signal to the indicator light when it is actually closed. The FSM outlines how to test, I tested both and if memory serves me I did not get conclusive results and chose to change them both, it worked.

Hope this helps, Cheers
 
Joined
Oct 20, 2021
Messages
12
Location
Minneapolis
Below is the best write up I’ve seen, and I used this and the FSM thoroughly to troubleshoot my 80. The write up is for the FJ80 so some things are different from the FZJ80 but overall it helped me tremendously.


Check to see if CDL is locked by turning a tight circle on dirt, CDL locked will give resistance and drag tires, unlocked will turn smooth.

I had this issue on my ‘96 FZJ80, I tested in a dirt lot by engaging Low Range, and definitely had the CDL engaged, but the indicator light would stay blinking. My CDL would engage but the L4 and or the 4wd indicator switch (located on top of transfer case) was malfunctioning and would not send the “closed” signal to the relay. I believe the L4 switch tells the actuator to close and the 4wd indicator switch sends a solid signal to the indicator light when it is actually closed. The FSM outlines how to test, I tested both and if memory serves me I did not get conclusive results and chose to change them both, it worked.

Hope this helps, Cheers
Thanks for that link. It is a great write up and I found that my CDL switch was bad and a new one should be here tomorrow. Thanks again.
 
Joined
Oct 20, 2021
Messages
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Location
Minneapolis
Below is the best write up I’ve seen, and I used this and the FSM thoroughly to troubleshoot my 80. The write up is for the FJ80 so some things are different from the FZJ80 but overall it helped me tremendously.


Check to see if CDL is locked by turning a tight circle on dirt, CDL locked will give resistance and drag tires, unlocked will turn smooth.

I had this issue on my ‘96 FZJ80, I tested in a dirt lot by engaging Low Range, and definitely had the CDL engaged, but the indicator light would stay blinking. My CDL would engage but the L4 and or the 4wd indicator switch (located on top of transfer case) was malfunctioning and would not send the “closed” signal to the relay. I believe the L4 switch tells the actuator to close and the 4wd indicator switch sends a solid signal to the indicator light when it is actually closed. The FSM outlines how to test, I tested both and if memory serves me I did not get conclusive results and chose to change them both, it worked.

Hope this helps, Cheers
Thanks again for the article and for the other users help too.

I found that there are 3 sensors on the transfer case, 2 were bad and 1 wasn't great. After following up with another thread, I read that the Beck Arnley 201-1788 Back Up Lamp Switch works for almost all of the sensors including the lockers.

I changed out the 2 of this style on the transfer case because they were bad and replaced the one on the very top with a Toyota OEM # 84222-60081 Transfer Indicator Switch. This one has a different end on it and a slightly larger opening on the electric connection.

Once I had all of the switches/sensors in, I could get the ABS light and Center Diff light to light up on the dash when I dropped in in Low. I tried to get the rear locker engaged but couldn't get that to work on my driveway but the front locker engaged after some turning and reversing.

I'll look into the rear but wanted to say thanks for the help from everyone. I was afraid that I was going to have to spend $1,000 to buy new front and rear lockers.
 
Joined
Oct 20, 2021
Messages
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Location
Minneapolis
Update on the diff lock situation and need help.

I ordered all new switches for the transfer case (all were dead). Took it out and was able to get the front to engage but the back didn't.

I ohm'd the rear switch and it didn't come out with great numbers so I ordered a new Beck Arneley switch. After adding that in it still didn't work.

I pulled the locker and put a 9volt battery to the terminals and it did nothing. I watched a YouTube video of a locker rebuild and he said not to put anything more than 9 volts to it.

Unfortunately, I ordered a new diff lock because the motor wouldn't turn (with 9 volts) and I couldn't take it apart due to corrosion. I should have tested it with a power probe the first time.

After adding in the new locker and switch, I found that I am not getting 12 volts to the motor when I turn on the switch. I validated with a Power Probe that when I put 12 volts to the motor it works and when I unlock the plug near the rear of the truck (by the jack) and I add 12 volts, the motor works.

I know that I am missing power from the switch to the rear of the truck. Does someone have a wiring diagram for this or steps/wires to check? I searched for a wiring diagram and didn't find anything on here.
 
Joined
Oct 20, 2021
Messages
12
Location
Minneapolis
I think it is the 4Wheel drive control (Diff ECU) that is the problem. I checked out the wire leading in and that is coming in with 12 volts. No power is coming out of the ECU however.

Does anyone know if these are programmed for the VIN? Also, can I find a used one that didn't come with lockers that would work?

20220510_105552.jpg
 

lp2k

Had a couple of drinks.. saw a couple of things
Joined
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Unlocked trucks don’t have that locker module

I’d test to see if you are getting power out of that locker ecu module. If you are then you prob have a wire cut somewhere under the truck or along the driver side main harness

Oh yea, if that locker ecu is toast, you will have to rebuild it. It’s been long gone and no longer being made.
 

lp2k

Had a couple of drinks.. saw a couple of things
Joined
Mar 31, 2012
Messages
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Location
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side note- some of those modules have gone bad due to moisture accumulating in that area. May have had some blockage in the passenger footwell at some point. If that area does get wet (even moisture), it will corrode and kill the little capacitors inside. Someone here was able to rebuild those modules with a solder gun and whatever. If you are by the beach with salt in the air, that will speed this up I am sure.
 
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