Various electrical issues...

[sidewayz2013]

Hello peeps. I been lurking NICOclub back when I had my old B14 and now I got me another Nissan (sort of) and like most used cars it has problems. So I decided to finally make a profile lol

I have a 1994 Q45A, but it does not have Active Suspension or HICAS (thank goodness). Electrical problems are limited to non-essentials, but much like I've gotten my Civic to do, I want everything to work in it. I bought this car as somewhat of a learning tool, in respect to electricals.

Problems:

1. The LF, LR, and RF windows all work individually, but not from the center console switches. RR doesn't work at all. I've pushed the lock switch to both positions with the same result. The center console switches do illuminate with the dash lights.

2. The "one-touch/auto" LF window feature does not work, but it rolls down when i have my finger on the switch constantly.

3. The RF and LR door locks do not work when I push the LF door switch one way or the other, but the LF and RR does. I think it's the lock motors.

4. The button/latch for the Fuel Door and Trunk release both do not work. I've put the trunk switch that's in the glove box to both positions with the same result.

5. The Auto climate control stays cold no matter what I set the temperature to. All the fan speeds work though, woo!

6. My memory seat does not memorize. All the seat/steering motors work except Lumbar Support.


Solutions I've tried:

1. Tried to find voltage source at the center console switches using a test light (currently all I have), by clamping the ground to a body ground (duh lol) and touching the tip to each pin of both connectors. The test light did not illuminate. When I looked in the FSM, each window switch appeared to be a simple rocker switch, but outputs go to the BCM. I need to learn more about the BCM and how it functions in relation to the car's accessories.

2. and 3. Ain't tried s*** for these lol

4. I tried to find voltage at the switch connector with my test light and nothing worked here.

5. Haven't tried anything but I think it's my blend door actuator.

6. I followed the FSM diag procedure and the LEDs blinked 9 times. The FSM only describes up to 7 blinks. So I dunno.


Tools available: 1992 Q45 hard copy FSM (came with the car when i bought it), 1994 Q45 FSM downloaded from Nico (thanks for that lol), a test light, and a Harbor freight voltmeter i got because it was cheap and I needed one... spare wire and a battery in case I need to isolate a circuit, and basic hand tools/ratchet and socket set. Have more at work, but that's what i actually own.

[sidewayz2013]

bump

[sidewayz2013]

bump...

[3Q Jay]

you said you need to learn about the BCM.
so.
What have you learned?

[EdBwoy]

...
Problems:
1. The LF, LR, and RF windows all work individually, but not from the center console switches. RR doesn't work at all. I've pushed the lock switch to both positions with the same result. The center console switches do illuminate with the dash lights.
Tried to find voltage source at the center console switches using a test light (currently all I have), by clamping the ground to a body ground (duh lol) and touching the tip to each pin of both connectors. The test light did not illuminate. When I looked in the FSM, each window switch appeared to be a simple rocker switch, but outputs go to the BCM. I need to learn more about the BCM and how it functions in relation to the car's accessories.
2. The "one-touch/auto" LF window feature does not work, but it rolls down when i have my finger on the switch constantly.
Ain't tried s***
3. The RF and LR door locks do not work when I push the LF door switch one way or the other, but the LF and RR does. I think it's the lock motors.
Ain't tried s***
4. The button/latch for the Fuel Door and Trunk release both do not work. I've put the trunk switch that's in the glove box to both positions with the same result.
I tried to find voltage at the switch connector with my test light and nothing worked here.
5. The Auto climate control stays cold no matter what I set the temperature to. All the fan speeds work though, woo!
Haven't tried anything but I think it's my blend door actuator.
6. My memory seat does not memorize. All the seat/steering motors work except Lumbar Support.
I followed the FSM diag procedure and the LEDs blinked 9 times. The FSM only describes up to 7 blinks. So I dunno.
...

Never owned a 1st gen, and neither have I read the FSM. These are my general guesses from experience.
1. At first glance I would guess the center stack is dead, but it seems you're on the right track with the BCM. How about a junkyard replacement?
Try jumping the RR window motor as well, to see if that isn't the problem because I feel that even if the motor was fine, the center stack wouldn't activate it with your current issues, but at least the door switch should - unless that is dead too.
2. Sometimes the switch will physically break and doesn't engage the one touch mini-switch, so to say. Does it feel loose, or even click?
3. Do these doors lock centrally or do they never lock at all? Assuming twisting the key twice would lock/unlock all doors in 94. That will tell you if the mechanism is jammed and in need of some lubrication. This is one of the most-neglected maintenance points on a car.
Or do you mean, they only work when you don't mess with the LF switch?
4. Remove the door panel and make sure the harness on this combo-switch is connected. If it is, then remove it and jump the terminals to see if your issues are further down the line. If my understanding of Nissans is still relevant, at the time these functions didn't go back to the BCM and should be fairly quick to diagnose/replace.
5. Short of checking the HVAC module, I am curious if you in-cabin sensor is blocked/ hanging in the wrong area to make it read hot all the time.
6. Didn't think lumbar support was memory recordable in any of the vehicles I've owned, maybe a G50 owner can confirm that.

[elwesso]

The stuff with the door windows/locks not working sounds like the LCU's in the doors. Those are a somewhat common failure point, I would not suspect that the center console window switches are bad.

Assuming with the trunk/fuel door release you don't hear the actuators working? That would also be supported by a door LCU, I believe.

Auto climate control is probably one of the blend door arms is broken. You can search around on the forum here to find out info on that.