Power door locks not working at all

I tried to search the forums but I couldn't find anything like my problem.

I am new to the forums because I recently bought a 2005 double cab but the power door locks do not work. They do not work with either the key fob or the lock switch on the front doors. I have to go manually unlock all the doors from the inside. I just checked all the fuses and they are all good. If anyone had any solutions, ideas, or could point me in the right direction for troubleshooting that would be greatly appreciated.

TIA

 

What method did you use to check the fuses?
Eyes, replaced with known good fuses, Multimeter ohm reading?

 

Are you getting power to the fuse(s)?
There is also a 7.5A ECU-B under the hood to check.
If so, go to the switch(es) and see if you have power to them.
If so, check your grounds.

It is highly unlikely the switch(es) would all go bad at once.

 

@Muddinfun

 

Maybe this will help a bit.

 

Hey Jimmy. In the above posted. I stated to “check power to the switch”
But if I’m reading it right, it looks like the switches just send a Ground to the Body ECU.
If so, I need to “correct myself” as there wouldn’t be power to to switch?

 

The switches just supply a ground to the Body ECU correct. The body ECU does all the actual power work internally so to speak.

It is what is called a Sinking Circuit as opposed to a Sourcing Circuit. If you want to read more about it:

https://instrumentationtools.com/difference-between-the-sinking-and-sourcing/

https://startingelectronics.org/articles/current-sourcing-sinking/

Basically are you switching the ground leg ( sinking ) or the power leg ( sourcing ) to energize a load.

 

Yes. Thanks.
I’ll will read about. I like to learn this stuff.

 

I checked all the fuses using a multimeter ohm reading/continuity test.

I double-checked the ECU-B fuse and it is good. I went to go check the power to the lock switch on the driver side but there is a ton of wires there so I did not know which one(s) to test. Electricity and power are not really my strong suit.

 

To check the switches just read across them with the connector unplugged using the resistance setting. Look at the schematic I posted above for the terminals to check.

Considering that all switches and fob are not working you need to concentrate on the common things between all.

Check the grounds continuity on the drivers switch, then all the other switches. Ground connection is the White wire with Black stripe.

 

Ok, I'll give that a shot tomorrow and will keep you updated. Do you have any tips on how to read the schematic that you posted? I barely know how to read/understand it. Thank you

 

Sorry I kept forgetting to make this post. But I checked the plug with a continuity test and there was no continuity. Any on what I should do next?

 

If the switch don't have continuity then it must be replaced.

 

It will only have continuity when the switch is pushed.

 

Do you think if the switches are bad it would cause the remote to stop working?

 

Is there a way I can test it when the switch is being pressed?

 

Yes but it may take two people.

With the switch unplugged connect the meter set to resistance across the contacts it should read OL ( Open Circuit ) and press the switch. It should go from OL to near zero Ohms. Same for both lock and unlock contacts.

 

I read above where you stated that electrical and power wasn't your strong suit. Do you know anyone that you could get to assist you in your area that does know about electrical?

 

Roll your windows down for these tests.


According to the diagram previously posted the lock wire at the switch is colored Light blue with a White trace. The unlock wire is GRay. You will also see a White wire with a Black trace and that wire is ground. With a multimeter put one lead of the multimeter in the plug while it's still connected to the switch on the Light blue/White wire and the second lead of the multimeter on the White/Black wire, set the meter to ohms, hit the lock button on the door lock switch and the ohms should go close to zero - if it doesn't then it's a bad switch. Same test for the unlock side of the switch, leave one lead on the White/Black wire and put the other lead of the multimeter on the GRay wire, hit the unlock button the the door switch and the meter should go close to 0 ohms. It's ok to hold the button down for a couple of seconds but once you see the change on the meter let go of the switch.

You can also use a test light. If you put the test lights clamp on a positive 12 volt lead (like the battery post) you can put the light on the Light blue/White wire to check the lock side of the switch, the test light should light up when the lock button on the door is pushed. Same for unlock side of the switch.

Once you've verified the switch is working properly you can use the same test light to check your power door lock circuit. Put the clamp of the test light on a clean metal surface, that silver U bolt that's in the door jam for the door latch works great, then put the test light on the Blue/White wire and the doors should lock without ever touching the door lock switch, just put the light on there long enough for the doors to lock. Then do the same with the unlock side of the switch.

Let me know how it goes and we'll continue once I know the results.

 

No. Think of the switch(s) as an attached "remote"...