Sasq40

Trying to get my rear locker working on my 2010 jk and can't seem to get the rear locker to engage with the factory switch. Opened up the diff and got the locker working by applying 12v to it. Tried checking the plug for power and not getting 12v there. Checked the fuse and it's good and therea power going to the relays, even tried other relays. Wheres the next place I should be check

Sixty4x4

Probably the open air wiring from the chassis/body to the diff has broken core. Best way to check is to do all the engaging, turn on the locker in your drive and get the stabbing probes for a multimeter that will penetrate the insulation once you expose the conductors out of that plastic conduit. They are syringe sharp. After you have finished place a small dab of silicone over where the stab hole was to prevent moisture from oxidizing the copper conductor. That procedure would start where the wiring leaves the body heading to the diff, check there for voltage then go to the first attachment on the diff. See how that goes.

Mr.T

Just in case, the Tcase must be in 4LO for the axle-lock to work. Another troubleshooting method is to use OBD2 to read the switch command input and also actuate the output. I haven't looked for those particular inputs/outputs, but Appcar DiagFCA has most everything like this, and Jscan and AlfaOBD probably have similar. There's a link to OBD scanner software in my sig below.

Junkyard junkie

I would check the voltage just above the body side connector, In case the connector is bad and then at the output of the relay. If the relay is good and has power going out, then I would just run a another double strand wire in a loom to the locker and solder in the plug to it. You can just secure this to the harness already there. Might save you a whole lot of work.

Junkyard junkie

If it is a bad wire as mentioned above, here's a replacement.

https://www.ebay.com/itm/Jeep-Wrangl...MAAOSwDFBaAibm

Or just the pigtail, if the connector is bad.

https://www.ebay.com/itm/Jeep-Wrangl...EAAOSweTlbqXjH