Rear Locker dash light "almost" on

[BMThiker]

So I'm driving home after having dinner with some friends last night and I notice that the red rear locker "engaged" light is barely illuminated on my dash. I get into my parking lot at our loft building and pull into a gravelly section. I put it in neutral and engage 4LO. Then I cycle through all my extras...A-trac on, Atrac-off, Rear Locker-on, Rear Locker-off. All my dash lights come on normal as I engage them. The rear locker light definitely comes on bright (normal) when engaged, but never fully goes out.

This morning I start my commute to work and no rear locker light. But then a couple miles down the road and I notice that again it is dimly lit.

I'm still running a basically stock drive train: auto tranny, t-case, axles, hubs, wheels, sensors, ADD in front, e-locker in rear. The only thing different is the ring and pinion gears (4.56).

What does it mean? faulty/loose connection in the e-locker?

 

[1911]

What does it mean? faulty/loose connection in the e-locker?

That would be my first guess, or a faulty/loose connection in the harness connectors to the transfer case selector switches/sensors, the 4WD ECU, or the ADD. Never seen that one before.

 

[Mtbcoach]

Agree with Lee. Sounds like you are getting some spurious grounding, I'd also inspect the wiring/harness, looking for any abraided/worn sections. It sounds to me like the it's just in the circuit related to the dash light, not the locking assembly since its not trying to engage the locker...

 

[BMThiker]

Need to crawl under and take a look-see. It does not engage the locker, so I would agree that it's probably a worn wiring loom/harness/connector and not the drive motor on the e-locker.

I've had the ADD go out on me and it tends to light up the TRAC/ABS lights, so ruling that one out (for now).

I hate electrical gremlins. It usually means I have to rely on the experts, and I hate not knowing it well enough myself.

 

[Mtbcoach]

Get one of those troubleshooting lights/conductivity checker. They can generate voltage as well as give a visual/audible check the wiring is conducting electricity.

From what I've been told, they FJC wiring is designed such that if a circuit loses ground, it turns the light on so that it alerts the driver of an issue. Start at the furthest away and work toward the light...

 

[BMThiker]

thanks Jerry.

 

[liljlandon]

I see this commonly on tacomas, moisture in the connection was one and the other needed the rear locker sensor replaced, iirc the back up light switch from a 5spd pickup (93ish) should work and is considerably cheaper.

 

[BMThiker]

That's good intel, thanks. You don't suppose it would have anything to do with this...

That weekend has cost me a lot of grief...unit bearings, starter and now, very likely, this.

 

[BMThiker]

Light did not come on over the weekend and all this week. Still haven't traced the source, if it is a grounding issue.

Maybe this is a sign that I haven't engaged 4WD enough this summer

 

[BMThiker]

Finally tracked this issue down. It was the two wire sensor that detects the position of the e-locker. Removing the sensor is really easy. Just need a 27mm socket and about 2 minutes of sliding around on a creeper. To provide a little more headroom, you can jack up the frame so that the rear suspension relaxes - giving you more clearance between the floor of the cargo area and the top of the axle.

Position yourself behind the rear axle and look down on top of the diff housing. There are two wiring harnesses and a breather tube all in the same area. The larger harness is a six or eight pin type, but you don't need to really move it. Remove the two wire harness by squeezing the catch release, then pull up. Now take your 27mm socket and put it over the entire sensor. A 27mm socket is generally big enough that it won't harm the plastic connector on top. Once you break the torque on it, you should be able to remove it by hand fairly easily.

Mine had a broken pin in the connector which was the cause for the ghost light. Turns out this is a common sensor in Toyota drive trains, so I tried a used one out of an 80 series transfer case. It bolted right in, but turned out to have a bad switch in it too. So I ordered a new one earlier this week (eep!! $70)

Part Number PNC 84222E

So the bottom line is that the 6/8pin harness controls the actuator which engages the e-locker, but the 2-wire harness detects engagement. My e-locker was physically engaging when I turned it on, but its possible the ECU didn't know it. The ghost light on the dash was the monitor that was alerting me to the broken pin in the connector - the light sometimes would fade or get brighter, but never came on 100% brightness.

Incidently, the sensor from the 80 t-case did not produce the ghost light, because the pins were still conducting whatever loop signal is being sent to it. But because the 80 sensor was bad internally, it made the locker light flash brightly whenever I tried to engage it.


broken pin on left

dang my camera phone sux
detent type switch

one from my diff and one from 80 series t-case

 

[Mtbcoach]

Wow, amazingly similar, got a similar issue on the rear axle I'm rebuilding for my 80...

 

[BMThiker]

Damn, it came back! Guess I'm going to be inspecting the wiring further upstream from the diff sensor.

 

[Mtbcoach]

Dang Rick, sorry to hear that. Nothing worse than chasing an electrical demon, good luck...

 

[BMThiker]

So that diff light issue eventually went away. I'm guessing water in the harness or something.


But, this morning on my way into work, it was raining and a few hard drops hit the roof...but then I felt this familiar pang in my gut. That wasn't just rain drops I was hearing/feeling. As I was rolling to a stop at a light the rear diff gave a couple of very light jolts. I turned off the radio and started off again...hmm nothing. Maybe I'm dreaming still. Next light I come to, I roll into a slow stop. Again, tick-tick-tickety-tick. FML!

I'm pretty sure its the ring gear/pinion. Going to pull the 3rd tomorrow morning and take a look-see. Already went over to ECGS.com and looked at the options. May be a heckuva lot easier to just buy one set up for $665(net, minus core charge) and return my core. Other option is to buy a whole rebuild kit for $465 and pay someone (ACC) to set it up. But since ECGS probably has this on the shelf I figure it will happen faster if I just buy the reman.

I've got a March 13th deadline (the Round Up).

 

[Mtbcoach]

Dude, you have had the worst luck with your rear R&P, crazy.

If Chase doesn't have one on the shelf, he'll do it in a day. He has had 24 hr turnaround for many of us dropping things off locally. The nice thing is that you just drop it in and go.

Sorry to hear this (again) Rick, I think you have the record for anyone I know...

 

[BMThiker]

Ok, may have over reacted...seems it was likely a u-joint on the rear driveshaft that was a little sloppy. It really wasn't as bad as others I've swapped out before, but we will see how it goes this week. *crossing fingers*