Blinking Rear Diff Light in 2WD

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Nailhead
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Blinking Rear Diff Light in 2WD

Post by Nailhead » Tue Sep 18, 2018 3:48 pm

About a week ago, I noticed the rear differential indicator light blinking as I’m driving down the highway. The truck was in 2WD, the diff lock selector was in “unlock” position.

Anyone have any idea what this might mean?


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Retired BLM Rig
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Re: Blinking Rear Diff Light in 2WD

Post by Retired BLM Rig » Tue Sep 18, 2018 4:58 pm

The flashing light is telling you that the final drive control module/smart bar sees a problem in the rear locker system. Check out this thread for more information. viewtopic.php?f=2&t=5132

Also, try cleaning and tightening all of your connections at the Smart bar and the rear locker connectors. Look for any damaged wires or pins and apply dielectric grease to the connections. You can also remove the rear cover to clean the sensor magnet and check the air gap between the magnet and the sensor. If all of that fails you’ll probably be looking at replacing the actuator in the rear axle.

I was able to fix mine by tightening the pin connections at the rear axle connector.

Good luck! :patriot:

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Re: Blinking Rear Diff Light in 2WD

Post by Nailhead » Wed Sep 19, 2018 4:52 pm

Retired BLM Rig wrote:The flashing light is telling you that the final drive control module/smart bar sees a problem in the rear locker system. Check out this thread for more information. viewtopic.php?f=2&t=5132

Also, try cleaning and tightening all of your connections at the Smart bar and the rear locker connectors. Look for any damaged wires or pins and apply dielectric grease to the connections. You can also remove the rear cover to clean the sensor magnet and check the air gap between the magnet and the sensor. If all of that fails you’ll probably be looking at replacing the actuator in the rear axle.

I was able to fix mine by tightening the pin connections at the rear axle connector.

Good luck! :patriot:
Cool— thank you very much.

What do you mean by “tightening” pin connections? Bending the contacts on the female side of the plug?


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RustyPW
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Re: Blinking Rear Diff Light in 2WD

Post by RustyPW » Wed Sep 19, 2018 7:48 pm

I posted this in another thread.

I'm starting to think about my locker issue I had this summer. I have a Rock Crusher diff covers on both front and rear. But they are almost the same shape as the stock covers. The only real difference is that the fill plugs are higher on the Rock Crushers. The issue I was having. On my trip out west. My rear locker light would flash after about a 100 miles of steady state driving at 70 mph, and would stay flashing. The next morning. The same thing. Would have to drive about a hundred miles before it would flash. Haven't done a thing to the diffs since that trip, and my locker light no longer flashes. Haven't driven over 50 miles per trip since then. Everything with them is ok. Everything works as it should. The only thing I did before the trip, was to change the lube in them. Mobil 1 75w90, 3 quarts in the front and 6 quarts in the rear. The same as I first installed the diff covers. Wondering now if my level is too high and causing too much heat. Affecting the locker sensor? Or my rotted tail pipe blowing exhaust on the right side axle tube. Which is fixed now.
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Re: Blinking Rear Diff Light in 2WD

Post by Retired BLM Rig » Thu Sep 20, 2018 9:42 am

Nailhead wrote:
Wed Sep 19, 2018 4:52 pm

What do you mean by “tightening” pin connections? Bending the contacts on the female side of the plug?
Yes.

IMG_1533.JPG
I used a dental pick tool.
IMG_1534.JPG
Inserted in the small hole behind the terminal to tweak in on the wall of the terminal.
IMG_1536.JPG
To do an even better job, you can remove the white terminal cover by releasing the tabs on both sides.
IMG_1537.JPG
The white cover separates the teminals and holds them in the proper position. There's also release tabs down inside the black plastic part to fully remove the terminals from the housing.
IMG_1535.JPG
Then you can you can remove the terminal and tweak the spring loaded tab inside the female terminal through the little access hole on the side.

:patriot:

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Re: Blinking Rear Diff Light in 2WD

Post by Bill2014 » Thu Sep 20, 2018 10:29 am

A set of Dentistry Tools comes in handy! :idea:
2014 Power Wagon Laramie
Titan V5 2.5" Receiver Pintle Hook
Warn wireless winch controller
.188" DOM White Knuckle Rock Sliders
Locker Bypass & Nanny Kill Switch

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Re: Blinking Rear Diff Light in 2WD

Post by Nailhead » Thu Sep 20, 2018 4:53 pm

Retired BLM Rig wrote:
Nailhead wrote:
Wed Sep 19, 2018 4:52 pm

What do you mean by “tightening” pin connections? Bending the contacts on the female side of the plug?
Yes.

IMG_1533.JPG
IMG_1534.JPG
IMG_1536.JPG
IMG_1537.JPG
IMG_1535.JPG

:patriot:
Got it— thank you. That oughta be fun while lying underneath the truck.


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