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2005 FX45 120K miles
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More speculation and theory: Why can I open an lock all the doors the first time? And why when it is hot outside my fob doesn't seem to lock/lock the passenger doors, but reliably locks and unlocks the drivers door?

Well... To state what I can confirm on my car: My new to me 2004 FX45 driver's door lock works fine and is reliable. However, the passenger front door and the passenger side rear door locks are weak and I sometime have to lock my doors twice to fully lock the latch with moves 1/2 way with every button push on the door console or with the fob. Note: Unlocking seems to be fine, but locking seems to be a problem.

I also have reviewed listed in the above post and I'm convinced the repair should not be done as shown using a hard washer. Instead you should use a bi-metal, PTC-R device, which is commonly used by refrigeration motors to "close" the circuit with 4 ohms resistance, and which acts to "open the circuit" when the PTC-R exceeds 1000 ohms. I.e., this is normally closed resistor that "opens" when the PTC-R heats up to 1000 Ohms with tanks only split seconds. ...And this what you want to protect the circuit I'm guessing is controlled by the BCM. ...Which means this door actuator motor with a PTC-R inside works like a resetable fuse that protects the BCM!!! ...So don't short the motor contacts using a simple lock washer as shown in the video. ...But other than this I learned something watching the video.

What I recommend is to NOT use a metal washer, but instead order some PTC-R on Amazon. And this is what a PTC-R looks like after you remove it from your refrigeration device (housing you don't need). It's that "wafer" the size of a nickel.
Automotive lighting Rectangle Font Auto part Technology


So when faced with repairing your old motor, I think you can do so by removing the PTC-R from this home refrigeration device you can order on Amazon for less than $12 and when you take the PTC-R out and put it into your Infiniti door actuator motor... assuming the PTCR will fit... your motor should start working strong again. Note: It does not matter if the PTC-R is round or square. But it has to fit so the motor can be reassembled.


Alternatively, you might try this, now that you know where the problem lies. ...Try taking out the old PTC-R from your old door actuator motor -- and just clean the contact points and reinstall.

So long as you don't break the brittle wafer when you pull it out you may find all you needed to do was clean the build up of corrosion. I would also try to reposition the PTC-R so you new contact points!

Note: These PTC-R devices are bi-metal semiconductor, normally closed, switches that "opens the circuit" when it gets hot and then resets to "close" the circuit when it cools down.

Or you can buy the whole motor on Ebay for ~$13ea and that's a better bet if you ask me:


CONCLUSIONS:

I think the reason ALL THE PASSENGER doors are affected, are because every time you unlock and lock the passenger doors with 2 clicks on the fob, all these actuator motors get worn out the same. So that sort of dispels the idea one bad motor affects the other.

And I would say the reason why my driver's door works fine is because I bet the previous owner already replaced the driver's side actuator assembly at the dealer, because otherwise the driver's side door would go out first since it gets the most use with just 1 fob button push.

So more than any other fix as mentioned above, I suppose replacing the Master Window & Door Lock Switch panel in the driver's door might help, but everyone says it's the motor inside the door lock actuator(s) that is causing this intermittent lock and unlock problem that does seem to be temperature dependent, because that what a PTC-R does; I.e., it heats up and then opens the circuit... rendering the motor inoperative.

CONCERNS: I have read that when the door motors fail completely, you can't open the door manually or with a fob and you get locked in or locked out. ...And then you have to open your door by taking off the inside door panels WITH THE DOOR CLOSED and that does not look like fun according to this video:

 

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Today I replaced my 2004 FX45 windows and lock switch Part#: 25401-7Y000.

What I learned is that my Infiniti group of switches is compatible 2004-2008 NISSAN MAXIMA 80961-7Y000. And then I learned Nissan Part# 80961-7Y001 supersedes Part #: 254017Y000, 25401ZK30B, 80961-7Y000. (Only $20 on Ebay with free delivery.)

However, in my case, I'm going to conclude there is nothing wrong with my set of master windows and door lock switches, because there was NO CHANGE when I removed my old Infiniti FX45 switch box and replaced it with the Nissan Maxima group of switches.

Therefore, this means I'm going to have to fix this partial door locking problem (which occurs after the 2nd or 3rd button push) by replacing the motor inside each door actuator. And when I do, I will report back. For now, I would say, if your group of driver's side master switches functions, even just a little, then I would say you should not bother changing out your windows master set of switches in the driver's door.
 

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As slight correction to my previous posts, when it comes to fixing the door closing in the wind, I would take apart the door hinge and add #8 washers to both side of the rubber pieces to shim it tighter. And the picture I posted only shows I put the shims on one side. That worked, but it will work better if you shim both sides.
 

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Here's a summary on how to fix your door lock-unlock problem on hot days.

There is a door mortor located inside the door actuator plastic casing. To fix this problem, you can buy an expensive door actuator or you can buy much cheaper door lock-unlock motors on ebay to fix your lock problem following these tips:

1) Watch this videos to learnen how to access the door actuator but don't use a washer to replace the PTCR. Instead replace the whole motor:


What's involved with removing the door lock actuator:

2) When you replace the motor you are also replacing the PTCR (as discussed in previous threads) which is located inside the motor. And it is this PTCR that's failing and/or the motor is producing more resistance (heat that opens the PTCR circuit) when you try to unlock and/or lock the door.

3) Pulling out the door actuator is a tricky; and you should lable your cables before you disconnect them. Also, this is a Pain In The Ass repair. (PITA)

4) Splitting the door actuator case is also hard to do the first time, because you maybe afraid you will break it, but don't worry about that. After you bust the tabs and split the case, you then will be able to replace the motor inside pretty easily. Then you can then glue the case-halves back together and use some duct tape to hold everything in place.

5) The rear door actuators work in a similiar manner as the front doors, but accessing the door actuator is more obstructed by the door frame and is a bigger PITA.

Note: I conclude the PTCR is the problem. Therefore, it's unlikely your master switch panel is the problem if you experience door lock-unlock problems on hotter days.
 
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