E-locker actuator troubleshooting

I have my actuator off and opened up. It looks clean and perfectly fine inside. However when I plug it in and press the diff lock button, the electric motor does nothing.

What can I troubleshoot next? Is there a fuse for the actuator? Or is it likely the motor is just bad?

Update: Fixed, see post #9

 

Are you getting voltage at the plug?

 

I don't know. I haven't tried that yet. Should there always be a voltage at the plug, or only for a few seconds after the button is being pressed/unpressed?

 

If you run it outside diff it will stick to 1 extreme. Open it back up and time it with the marks on the case. Use 9volt battery to test outside if diff.
Did it work before?

 

No, it hasn't worked since I've bought the truck. The dashboard light just flashes.

With the actuator off I manually pushed the rack gear inside the diff to the left to engage the locker, and then both wheels turn in the same direction and the dashboard light stopped blinking. So that works.

With the actuator off & opened up, I tried plugging it in and pushing the diff lock button to see if the motor was trying to turn, but nope.

So I'm thinking either the motor in the actuator is bad, or there's an electrical problem elsewhere and the actuator motor is fine. I haven't opened up the motor compartment on the actuator because the screw heads are stripped.

You said to use a 9 volt battery to test the actuator. The plug has 5 pins. Do you know which pins I should use to test it?

 

Bad lock position sensor?

Edit: This doesn't make sense now that I read that the light stops flashing when you lock it manually

 

This might help

 

Update: It's fixed!

The old actuator was not getting continuity between the light-green/red & light-green wires, indicating something wrong with the actuator motor. I bought a new actuator from RockAuto ($400 shipped). However, that did not yet fix my problem...

I was now of course getting continuity on the motor wires at the new actuator (note: the new wires were different colors), but not at the 4WD Control ECU (located at driver's kick panel) harness on pins 2 & 3 (labeled M1 & M2). These wires go from the ECU to a connector under the driver's seat (BN7), then to a connector near the driver's side wheel (BO1), then to the actuator connector which then drive the actuator motor. Long story short, I had to clean the connector that the actuator plugs into and clean the BO1 connector. I also had to slightly bend the BO1 pins (pins 3 & 5) so they would make good contact. That finally got me continuity at the ECU, but it still didn't get the actuator working...

It turns out the 4WD wire in the ECU harness (pin 8, grey wire) would not ground when I shifted into 4-Lo (dunno why). I wanted to do the grey wire mod anyway, so I cut the wire and grounded it to the same bolt that holds up the ECU. Now the diff lock works like a charm.

For future people trying to fix this, use the insp.pdf mechanicjon posted (page SA-199 from the FSM) and the Rear Differential Lock wiring diagram from the FSM. Page SA-200 provides tests to troubleshoot the actuator. Mine failed the first test (continuity between M1 & M2 at the ECU).

 

Attaching wiring diagram from 2003 FSM

 

Thanks, this might've been my issue as well. I'll revisit at another time. For now I have the harness from wheelers, or another company. Can't remember.

 

It's worth a shot. It only takes a few minutes to get the kick panel off, unplug the ECU, and run through the tests with a multimeter. If you don't get M1 & M2 continuity at the ECU but do at the actuator then it's just a dirty plug.

 

I'm posting the old actuator for sale in case anyone wants the internal parts & housing, or perhaps someone can fix the motor.

https://www.tacomaworld.com/threads/e-locker-actuator-with-broken-motor.618779/

 

I was able to fix the actuator motor. I cleaned the copper contacts that the small spring-loaded metal things touch, and I re-greased the ball-bearing on the bottom of the worm gear. It works great now.

I posted it for sale:
https://www.tacomaworld.com/threads/working-e-locker-actuator-for-rear-diff.619510/

For future readers, it's somewhat of a bitch to get those two spring-loaded metal bits in. Try removing the motor housing without pulling the motor & worm gear out with it (there are magnets in the housing that will pull it all out). If you have to remove & re-install the motor/worm gear and thus have to deal with the springs, I used toothpicks to hold them in place then yanked them out once the motor was in.

 

Like what paulwal experienced my #8 wire in the diff lock ECU wasn’t grounding. Like him I went ahead and did the gray wire mod which solved my grounding problem and now my e-locker works! Thanks to @paulwal for his contribution to resolving this issue.

 

Ok im having some issues with my actuator/wiring. So whenevee i tried using locker it would noot lock up and kept blinking. I tried the driving in circles to maybe break it free. Still nothing. So i went ahead and did grey wire mod and still nothing. Just kept flashing. Cleaned out my actuator and nothing. I borrowed a friend's actuator that worked and put it in and still nothing. Ive looked thru my wires and they all seem fine. The rack inside words and then stays solid. Also how do u guys bench test the actuator? 9v battery?