Hello again having just got my 90 back from long term loan, I am trying again to sort out the DL on it. Karl has kindly sorted out a 2nd hand replacement for me and it tested out fine before fitting, however The feed wires are dead at the diff end plug and the DL light is flashing on the dash, Can anyone point me in the right direction please. Cheers Rob
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KDJ95 Diff lock relay
- Thread starter robthebox
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Hello again having just got my 90 back from long term loan, I am trying again to sort out the DL on it. Karl has kindly sorted out a 2nd hand replacement for me and it tested out fine before fitting, however The feed wires are dead at the diff end plug and the DL light is flashing on the dash, Can anyone point me in the right direction please. Cheers Rob
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Hi,
Start by checking the 20A 'Diff' fuse in the small fuse box by the driver's right knee:
After that I'd suggest tracing the wiring from the dash switch, checking continuity as you go.
Also - check that the Detector Switch that sits in the Diff above the Locker is working - mine wasn't and had to be replaced.
You have to be in Low Ratio before the Diff Lock will work. The various ECUs know you are in Low because of a Detector Switch on the top LHS of the gearbox.
It would be worthwhile checking the connections from the gearbox switches as well.
Good luck.
Bob.
Start by checking the 20A 'Diff' fuse in the small fuse box by the driver's right knee:
After that I'd suggest tracing the wiring from the dash switch, checking continuity as you go.
Also - check that the Detector Switch that sits in the Diff above the Locker is working - mine wasn't and had to be replaced.
You have to be in Low Ratio before the Diff Lock will work. The various ECUs know you are in Low because of a Detector Switch on the top LHS of the gearbox.
It would be worthwhile checking the connections from the gearbox switches as well.
Good luck.
Bob.
Thanks Bob I'll let you know how I get on. Cheers Rob
Hi Bob, thanks for your kind help. all was ok and no faults found on plugs, sensor, actuator and fuse. I have got to the point where I am waiting for an auto spark to test the wiring between the switch and the diff. Plus everything in between. At least the spark will have an assistant, hopefully between the pair of us we'll get there.
Cheers and thanks again..... Rob
Cheers and thanks again..... Rob
Hi there all, We are having a bit of a battle trying to sort out the Diff lock on this one. I have a working one off Karl (thanks Karl), and the switch on the diff (or the sensor) is working. We have traced the wiring to a 4x4 control box behind the rear seat above the nearside wheel arch. So went on eBay and got a used one. And hey presto, no change.
Can anyone direct me to a circuit diagram of a manual version 2001 kdj95. I am determined not to let this beat me.
Got my fingers crossed cheers Rob
robthebox, Today at 3:06 PMEditReport
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Can anyone direct me to a circuit diagram of a manual version 2001 kdj95. I am determined not to let this beat me.
Got my fingers crossed cheers Rob
robthebox, Today at 3:06 PMEditReport
#1+ QuoteReply
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Thanks Flint, I'll get it printed up and check it out. Apologies for the slow response.
Ok, happy to say that we finally have a result.
On top of the gearbox behind the gear lever there is a lock out switch, it was faulty and very difficult to get to, so it is now by passed.
The switch function stopped the diff lock being engaged in high ratio.
All working well now. Thanks to Bob for your input including the faulty switch position which, once tested, was easily fixed. Also Karl for sorting out the replacement diff lock and giving a live tutorial on the the wiring up..... and finally thanks to Flint for the Wiring diagram which was crucial in tracking the switch fault.
Nice to have this behind us ..... Thanks guys
On top of the gearbox behind the gear lever there is a lock out switch, it was faulty and very difficult to get to, so it is now by passed.
The switch function stopped the diff lock being engaged in high ratio.
All working well now. Thanks to Bob for your input including the faulty switch position which, once tested, was easily fixed. Also Karl for sorting out the replacement diff lock and giving a live tutorial on the the wiring up..... and finally thanks to Flint for the Wiring diagram which was crucial in tracking the switch fault.
Nice to have this behind us ..... Thanks guys
Last edited:
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JaspaJami
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I hope i can continue to this same topic, because i have kind a same problem
I have RHD automatic KZJ95 Land Cruiser, rear diff is on and i cannot disconnect it. Fuse seems to be ok. So should i try to check those switches at top of diff (if i understanded right) and somewhere in the stick where i put low ratio, or are those switches only meaningful when trying to switch lock on? Where this 4wd ecu is located?
I have RHD automatic KZJ95 Land Cruiser, rear diff is on and i cannot disconnect it. Fuse seems to be ok. So should i try to check those switches at top of diff (if i understanded right) and somewhere in the stick where i put low ratio, or are those switches only meaningful when trying to switch lock on? Where this 4wd ecu is located?
Firewout
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Hi jaspa,
Rob mentioned above where to find the ecu.
Did you try to measure 12v directly near the diff lock motor at the connector?
In my 80, the relay contacts in the ecu were burnt and the electric loom melted away, so there is a lot of stuff that can go wrong with those diffs.
You just have to check it out systematically. Maybe start at the ecu and measure if the signals go in and out and listen for the relay to click when trying to engage/ disengage.
Good luck!
Rob mentioned above where to find the ecu.
Did you try to measure 12v directly near the diff lock motor at the connector?
In my 80, the relay contacts in the ecu were burnt and the electric loom melted away, so there is a lot of stuff that can go wrong with those diffs.
You just have to check it out systematically. Maybe start at the ecu and measure if the signals go in and out and listen for the relay to click when trying to engage/ disengage.
Good luck!
JaspaJami
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We try to get signal from motor connector and only one that we found was signal for the indicator lamp at dash (signal was jumping up and down in same cycles than indicator).
I was thinking that when i found ECU i can make most of the measurments from there.
"4x4 control box behind the rear seat above the nearside wheel arch"
Nearside, so in RHD car leftside? Is it accessible from where and how? I also have third seat row in my car, dont know if they are disturbing accessibility
I was thinking that when i found ECU i can make most of the measurments from there.
"4x4 control box behind the rear seat above the nearside wheel arch"
Nearside, so in RHD car leftside? Is it accessible from where and how? I also have third seat row in my car, dont know if they are disturbing accessibility
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I have this photo from my Right-Hand Drive '95' from when I was modifying the rear lights.
Could that be the control box above the wheel arch ??
I doubt the entire wiring harness is reversed for Left-Hand Drive so you may find it on the Left Side (looking forwards).
Bob.
Could that be the control box above the wheel arch ??
I doubt the entire wiring harness is reversed for Left-Hand Drive so you may find it on the Left Side (looking forwards).
Bob.
JaspaJami
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Found ECU exactly from that location and its looks totally ok. Havent measured yet, but i believe its working ok.
If we check that electric schema that is up the thread. What are those cables that goes from ECU to motor? LR and L are supply to motor itself, but how? Is another one +12 and other one GND, or is motor getting GND only via chassis (that WB cable)? Is it changing direction by swapping polarity of those, or by leading +12v to either one of those?
And what are the other two, from ECU GY and G (G is marked as a lock, GY i cannot read)?
If we check that electric schema that is up the thread. What are those cables that goes from ECU to motor? LR and L are supply to motor itself, but how? Is another one +12 and other one GND, or is motor getting GND only via chassis (that WB cable)? Is it changing direction by swapping polarity of those, or by leading +12v to either one of those?
And what are the other two, from ECU GY and G (G is marked as a lock, GY i cannot read)?
jordan_sorabjee
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Long shot but I want to try revive this thread.
I have had issues with my rear diff lock ever since I owned my 1kz. I eventually found the problem, it was a broken wire to the Rear Diff Lock Position switch. A few months after fixing it the same issue. I traced it to another broken wire, fixed that, but I made the error of connecting the position switch wires the wrong way round. No issue, I swapped them back and it worked. A few weeks later it stopped working again. I have traced all the wires and cant find a break. Unusually this time, I cannot hear the relay making any noise. Could this be the issue? Maybe I caused damaged when I got the wires the wrong way round? Where is the relay switch for the diff lock located.
Alternatively, how do I test the 4WD ECU?
Thanks in advance.
I have had issues with my rear diff lock ever since I owned my 1kz. I eventually found the problem, it was a broken wire to the Rear Diff Lock Position switch. A few months after fixing it the same issue. I traced it to another broken wire, fixed that, but I made the error of connecting the position switch wires the wrong way round. No issue, I swapped them back and it worked. A few weeks later it stopped working again. I have traced all the wires and cant find a break. Unusually this time, I cannot hear the relay making any noise. Could this be the issue? Maybe I caused damaged when I got the wires the wrong way round? Where is the relay switch for the diff lock located.
Alternatively, how do I test the 4WD ECU?
Thanks in advance.
diggerdave
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I can't help with the ECU side of things, but the mechanism of the diff locker does have a limited life particularly if it is unused for a long time so I would also try to rule out a mechanical issue too.
jordan_sorabjee
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Could be but, I have used the diff lock enough to stop it failing. I'm told there is a trick with a 9v battery you can do to test it but not sure how to do it. I'm fairly sure its an electronic issue as I can no longer hear the relay when I turn the switch.
jordan_sorabjee
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Solved. Feel like a bit of a idiot. Went and checked the ECU, everything was fine. Went back and checked all the wires again (using a multi meter this time). Two more wires had broken including the earth to the sensor, hence why I thought that was the problem to begin with. Reconnected and jobs a fish; the diff lock is back in action!
