FZJ80 CDL Problem

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Dec 16, 2011
CDL Madness

CDL Sensor Switch (4wd Indicator Switch) on the transfer case - On my 80, I removed the switch (wasn't working) from the Tcase and cleaned it, with both 18v battery power and some contact cleaner. It tests nicely for continuity when pressed and also resistance. I can hook it into the harness connector and manually cycle the switch to activate the CDL light on the dash AND engage the RR&FF diff locks. The paperclip jumper test does the same. Problem is, it doesn't work when I install it back into the transfer case. The switch from my LX performs exactly the same when swapped into the 80.

What the hell am I overlooking on the 80? IE, why does the switch NOT function when installed? Both trucks have the Pin-7 Mod and CDL switch on the dash. I've swapped the Sensor Switches around 3 times and each truck/switch combo always get the same results outlined above.

IDIOT NOTE: I'll be jacking up the saggy-spring LX next time I have to crawl under it 100 times. I cursed it each time, and even more when I slid comfortably under the lifted 80.
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For reference for others needing to remove the CDL Sensor Switch...27mm is the wrench size, but you'll likely need a small adjustable wrench to get to it up in the tight spot where it lives. 1-1/16" is the SAE equivalent.


Cleaning the switch with current.
So when pushed in the TC it doesn't engage the CDL at all? No sound from the motor or just no light on the Dash?

Does the CDL come on when shifted into 4Lo?
Problem solved. I guess I needed to drive the 80 around more than I did last night. Symptoms this afternoon were the same as posted above. It started working just dandy after a few trips up and down the driveway, plus rowing the shifters a bunch more. CDL light activates and both diff locks engage.

@lt1fire - There was no light, and the only thing I could hear was the relay in the kick panel.
Sometimes the actuators just get sticky.... that was what was wrong with my 100.
From the description you give it sounds like the indicator switch is fine and the CD is not locking. Next step is to remove the diff lock actuator and see if you can get it to cycle. If not, first suspicion would be the rotary contacts inside the actuator. When pushing the CDL switch does the diff lock motor come on?
When pushing the CDL switch does the diff lock motor come on?
It does now, but your post just made me view the locking process in a new light for some reason. I'm actually kind of glad I didn't pull the actuator last night. That would have been an unnecessary major pain on this rusty truck.
If you need to remove or replace, not that hard (with a flat driveway) , see below starting on post 223. Mine starting acting up and eventually stopped working.

Izzy's amateur hour

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