Power Windows & Locks

[zarc529]

I need help with my windows and locks in my 94 Q45. Firstly, if i press the lock switch on the panel on my drivers side, it only locks my driver side door. None of the other doors lock at all. I have no idea what could have caused this.
On top of that, I can only raise or lower my drivers side window! The switches in the center console don't do anything, nor do the switches on the doors themselves! It's a really weird problem and kind of have a suspicion its the LCU's in the door panels but I may be wrong. Any help?

[goody90q45]

Unless the windows and locks have been failing one at a time over the past few months I would suspect that the main LCU in the driver's front door has failed. Before you go buy a new one (at least $120) try opening it up and see if there are any melted solder joints, usually found at one of the connector pins. The ground circuits on many of the sensors in the Q45 tend to melt so you may find it to be an easy fix, as simple as melting the solder at the joint and adding a drop more for good measure.

[zarc529]

Ok. so the Lcu in the drivers door is what controls everything else? Ill try to look into it thanks.

[goody90q45]

Yes. If it was just the controls in one door having issues then you'd suspect the LCU in that door but since it's all doors and all windows it's likely the main LCU in the driver's front door.

[zarc529]

Hey, I really appreciate your help! I just had one more quick question. Does the LCU have anything to do with the courtesy lights in the car. Just like the other two problems, the courtesy light only works on the drivers side door and the other 3 doors dont light up at all when opened. Could this be connected to the problem too?

[Q451990]

The LCUs do control the "step lamps" as Nissan calls them, so I'd say there's a good chance that the problem is related. Check out the FSM (factory service manual) available at www.nicoclub.com/FSM/ and look on page EL-201. The actual discussion of the LAN system starts on EL-61, and has a good bit of diagnostic stuff you can do with a multi-meter.

Heath