Rear Locker Doesn't Engage? (1 Viewer)

[aljogav]

When I turn on rear locker switch on my 98 LC red dash indicator light just keeps blinking on high or low (did the pin 7 mod). Could this be a simple fuse or relay issue? Just hope it's not the e-locker itself going bad.

 

[SmoothLC]

You typically have to drive it a little to get it to engage. And turn some figure 8s.

 

[aljogav]

Did drive it forward, backward, slow speed, but not figure 8's. Will try that tomorrow before I start looking into fuses and relays. Thanks.

 

[bmw635]

Make sure to do it on dirt, gravel, not concrete or paved.

 

[White Stripe]

First u gotta be in 4 low. If the 4low engagement switch is bad then the ecm won't know 4low is engaged. If the locker switch on the diff is bad, the locker may work but the ecm won't know it and the light will also just blink. All those switches on the tcase and diff have a tendency to stick and not work because they haven been used in years. Center diff lock has one also. Good news: they are cheap.

 

[spressomon]

To verify whether the locker is working: Raise & properly support the rear wheels so both can be turned freely (block one or both front wheels). With the key in the ACC position (don't start the engine). Transmission in neutral or drive. Engage the locker switch then rotate, by hand, the rear driver's wheel. If the locker is functioning properly you will see both rear wheels turn together in the same direction.

 

[aljogav]

Thank you for your responses. I was able to confirm the rear rear locker is not engaging. Where can I find the fuse and relay that activates it? I looked under the hood on the fuse box right behind the battery and there's not one labeled rear locker. Would appreciate if someone can point me to the process of identifying which part is defective. Thanks much guys.

 

[spressomon]

^ did you have a close look at the wiring loom where it enters the locker/rear diff? If not then you'll need to peel back the electrical tape and plastic surround. Years ago I found, on mine, one of the two wires broken ...

 

[ted4whlz]

Also, maybe double check your pin 7 mod. I saw on here a while back that someone had taken out the blue wire with a black stripe instead of the black wire with a blue stripe, just FYI...

 

[marcfj60]

When is the last time you engaged the locker? When I bought my '99 in '09, the PO had never turned the switch. I was probably the first person to operate it since it left the factory. It took a while of forward and backward motions on dirt, then laying under the truck, smacking the actuator until it finally clicked. I suspect 10 years of grease that wasn't moved around had caused it to hang up a little.

 

[aljogav]

Finally worked after driving forward, backward a few times. After I turned it off and turned it on again to see if it'll work, it won't engage again! Looks like I need to take this thing apart, clean and lube it. I hope that's all it needs or perhaps a new locker switch at the diff is going bad.

 

[landylover21]

Glad you got it working again; as with anything, a good bit of exercise once in awhile will work wonders!

Just for future readers, the PIN 7 mod only prevents the center differential from locking automatically when shifting into low range on the earlier 100s and nothing to do with the rear.

I had a similar hang up a few years ago but I finally got mine to engage after driving around in a field with it turned on. I was so paranoid that it'd be stuck in the locked position but it locked and unlocked just fine after driving around in circles of varying diameter. I also did a mod where the rear can be locked in high range with a rocker switch above the rear diff lock switch as well but don't ask how I did it, I found it on a thread here and that was years ago. This mod also changes the shift timing so it shifts like it does when in low range and locks out overdrive. When it stopped working suddenly a few months ago I took a look underneath and it turns out the aftermarket exhaust I had installed melted the wiring harness

 

[SmoothLC]

Personally, I found that if I regularly use it every few weeks, it's good to go. In the past, when I haven't used it, it seems to "stick". Keep in mind I had to replace it a number of years ago.