Diff lock light coming on randomly and staying on?

[SiberianPatrol]

Mates. Last week I drove my last trip back up our winter road which is now thawing and degenerating quickly. Total distance was about 360km of a combo of mud, slush, ice and snow. Thankfully the ground was still frozen, otherwise the going would have been a lot rougher than it was. About half-way back on the road, after going through quite a few large puddles of muddy, icy water my diff-lock light came on on the dash and with it the usual ABS light and warning horn when I accelerated above 20km/h. However, the diff lock was never engaged. I stopped and tested it multiple times and I could hear the vacuum engage and disengage when I toggled the diff-lock switch in the cab. Engaging and disengaging the diff lock, engaging and disengaging the 4wd high and low didn't make any difference, the indicator still stayed on.

I finally just ignored it and drove the rest of the way back and after a while the ABS warning tone went away, but the lights still stayed on. Got back to our home and gave the Patrol a good washing, but haven't been able to get the undercarriage really well yet. Lights are off for the most part now, but they still come back on occasionally.

What could have caused this and what do I need to check for? Does it just need a really good washing or do I need to track down a fault somewhere? I'm at a loss because everything functions as it should, just the indicator lights come on and off at random.

[growler2058]

Have a look here mate. Theres a few posts worth a read
http://www.nissanpatrol.com.au/forums/search.php?searchid=7573441

[SiberianPatrol]

Thanks, Growler. Unfortunately the search function isn't working on forum for me at this time and I can't follow your link or do a search. Will try later. Maybe it will sort itself out.

[jack]

Have a look here mate. Theres a few posts worth a read
http://www.nissanpatrol.com.au/forums/search.php?searchid=7573441

Link doesn't work for me either growler

[SiberianPatrol]

Just to clarify since I forgot to include it in the first post, I have a 1999 GU RD28ETi

[growler2058]

Ahhh bummer now I'm on my phone


Sent from my iPhone using Tapatalk

[SiberianPatrol]

Anyone able to shed some light on this for me?

[Mike02Ti]

From memory when i was mucking around with mine the buzzer itself is built into the switch for the diff lock. There has been issues apparently before where these switches have gone bad. Maybe this is the issue.
Failing that maybe check the wires going into the actuator. Also have you tried the good old disconnect the battery trick?

Sent from my SM-G920I using Tapatalk

[Yendor]

The diff lock solenoid is located on the passenger side firewall. The Blue wire with a White trace should have power when the diff lock switch is on. The Pink wire with a Black trace should have power when the diff lock switch is off.

It could also be a problem with the diff lock engaged switch in the diff. This switch switches an earth when the locker is engaged. You will need to check the operation of this switch and make sure the Green wire with a Red trace that connects to it isn’t shorted to ground.

You could also have a vacuum leak in one of the hoses that run between the solenoid and rear diff. Check both of these.