… door locks gone crazy

I think there is a relay that sends 12v to your lock relays. Worth a check.

Shubbydog said:

Have you checked your relays for the power locks? After all the steps you took already and no luck…. Sounds like a suspect relay or bcm freak out.

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Appreciate the input. Definitely crossed my mind that BCM has fried/glitched out somehow. But hopefully not *crossing fingers* .. but in regards to the relays.. Happen to know location & relay#(s)?

My truck didn’t come with an owners manual so i am stuck resorting to google. Google search pulled up this info:





Which is weird as hell.. because i scanned every block and there is only a vague entry for “left doors” .. but there is no entry anywhere for “right doors”.. actually there is no other entry anywhere for ANY other doors.. so the left doors are controlled by fuses/relays but the right doors are not.. lol wtf .. that does not seem right.

Plus #43 under the dash looks like a small fuse from the diagram, def not a relay. There’s a crap ton of relays on the engine fuse block that are either unused or don’t have info available on what they are

It’s possible I’m overlooking. Getting late and tired right now.. but when i looked on another website pretty much the same info came up.

you might want to check the x1 connector passenger side and see if there is corrosion or maybe bad connection in there.
all the pins to door locks on are that connector

So i checked that harness and it’s impeccable. I wanted to test each relevant pin with the multimeter but apparently i don’t have a setting low enough to get a proper measurement, or i just don’t know wtf I’m doing (or both) electronics is not my strong point

But to the feel test the pins are secure and tight and so clean looks like it just rolled off the assembly line.. wouldn’t you all agree ??










I also looked at fuse#43 on the driver’s side.. looked OK to me


I am starting to think BCM, or pinched wire somewhere in any of the harnesses..

Orrrr…. What? Other than the current possibilities of:

-Pinched/corroded wire hidden somewhere either in wiring harnesses or battery cables
-BCM issue

What else could it be?

PPV_2018 said:

So i checked that harness and it’s impeccable. I wanted to test each relevant pin with the multimeter but apparently i don’t have a setting low enough to get a proper measurement, or i just don’t know wtf I’m doing (or both) electronics is not my strong point

But to the feel test the pins are secure and tight and so clean looks like it just rolled off the assembly line.. wouldn’t you all agree ??

View attachment 447962

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I also looked at fuse#43 on the driver’s side.. looked OK to me


I am starting to think BCM, or pinched wire somewhere in any of the harnesses..

Orrrr…. What? Other than the current possibilities of:

-Pinched/corroded wire hidden somewhere either in wiring harnesses or battery cables
-BCM issue

What else could it be?

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Ya, looks clean, figured it might be worth a shot to take a look at anyway.
it looks like its going to take a deeper look, maybe you can take a meter and probe those pins/wires and see if one is guilty
I have no idea what they should ohm out at, maybe @mikez71 has that data or @swathdiver
I would suspect one of them is possibly the cause or will lead you to the cause.

#44 in the passenger side fuse box is door window motor. I think that relay is for right side doors and windows. If there is a bad or corroded connection, or bad relay you would get strange issues that happen intermittently. Could even be stuck and when it shakes you get connection in the relay. It would be cheap and easy to replace both side relays and see what happens. Good luck.

Shubbydog said:

#44 in the passenger side fuse box is door window motor. I think that relay is for right side doors and windows. If there is a bad or corroded connection, or bad relay you would get strange issues that happen intermittently. Could even be stuck and when it shakes you get connection in the relay. It would be cheap and easy to replace both side relays and see what happens. Good luck.

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It is indeed interesting you say that, because remember in post #24 just above when i said i checked fuse #43 ?



As i had posted previously, online search showed that fuse as left doors. Looking through the upfitter guide that @Doubeleive provided, i now see that it’s just as @Shubbydog mentioned but for the driver’s (left) side window..:


(Left side)


(Right side)

I pulled #43 to inspect it, but i couldn’t see a broken contact so i figured it looks fine.

Got in the truck an hour ago to go up the street and I’m greeted with this message:



wtf it just gets weirder. Guessing that has to do with me pulling #43 earlier.

For clarity: is #43L & #44R a fuse or a relay? Anyways, it’s a weird looking fuse(relay?).. I’ll pull #44 passenger side tomorrow and check it out. If not maybe source two of those and replace them.

Bad driver door module? (switches)

curious to see where this ends up in case the same thing ever happens to mine or the wifes

Doubeleive said:

curious to see where this ends up in case the same thing ever happens to mine or the wifes

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One thing’s for sure when we get it solved for real it will provide easier troubleshooting & save the next Tahoe/yukon owner a lot of head and heartache . . .

mikez71 said:

Bad driver door module? (switches)

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more specifically driver door module meaning the door lock actuator or the actual switch you press to lock & unlock?

When i think about it, if the switch on the side of the door is faulty it could definitely explain all of this foolishness.