Please HELP with this weird electrical problem

[acharania]

I have a 2016 Nissan Rogue SV and both the side view mirrors (door mirrors) are not working. On the left, the turn signal light works but on the right, the turn signal light is also not working. I have done the following troubleshooting:

Already replaced the remote switch with brand new one.
Thinking that the mirror assembly/motor was bad, I replaced it with a working one but no change.
Checked all fuses in the driver side and find that three switches are not getting power at all. These are fuse numbers 19, 20 and 21. As per service manual Mirrors.pdf, it is fuse number 20 that powers the door mirrors.

How do I continue further troubleshooting to find why these fuses are not getting any power? Please help.

[VStar650CL]

Anytime stuff in a door on a gen2 Rogue doesn't work, the first thing to check is the door umbilicals. Peel back the rubber boots and look for this sort of cracking and fraying:

The door mirrors on a '16 are a straightforward 4-way switch setup, you can find the wiring diagram starting on MIR-10 here:
https://www.nicoclub.com/service-manual ... %2FMIR.pdf

[E.T.]

Perfect, thanks. If these wires are bad, how big of a hassle is it to fix on my own?

[VStar650CL]

Replacing the door harness isn't hard, the only tough part is that they don't give you quite enough slack to pull the largest of the three connectors through the service hole and into the footwell. So splitting that connector can be a finger-killer. With door harnesses, after I get the umbilical portion split, I usually pull that portion inside the door and then string the new harness alongside the old. That way you don't mess up the routing.

I don't recommend ever attempting to repair the existing harness. The only way a repair in that spot would ever last is if you replaced all the wire sections which run through the umbilical, such that your splices were all inside the door and inside the car where they would never need to flex. Putting splices in the section which flexes is suicidal. With new harnesses costing under $200 online, it's also silly.

[E.T.]

Thanks! I looked at the wires in the umbilical (at least the ones in between the door and the body) and they actually look really good. Did not see any breaks or anything odd.

[VStar650CL]

Then you'll need to trace the wires for the handle to see if there's a break. There are two different circuits involved, the antenna and the button (obviously if the BCM never sees the button as being pushed, it will never activate the antenna to transmit). You can find the wiring diagram for the handles on DLK-71 here:
https://www.nicoclub.com/service-manual ... %2FDLK.pdf

The buttons are easiest to check, put a voltmeter on the wire going to the BCM and see if it goes to 0V when you press the button. If it reads 0V all the time then the wire to the BCM is compromised, if it reads voltage (could be either 12V or 5V) all the time then there's a problem with the ground wire. For the antenna, you need to ohm both wires from end to end and to each other (make sure both ends are disconnected while doing it, or you can blow the BCM). You should read near 0 ohms on both wires and infinity (OL) between the two wires. Since we know the handle is good, if the button works and the antenna wiring checks okay, then either the transmitter or receiver in the BCM is blown.

That all said, if the car has a sunroof then check for water intrusion on the driver's side before doing anything else. Water coming down the A-pillar from a blocked sunroof drain can soak virtually any of the connectors in and around the kick panel (and that's a whole bunch of them, including the BCM itself).

[E.T.]

Thanks, I appreciate all the help! It's weird because all the connectors look good, wires look good (that I can see). I'll have to try testing them with the meter. If I need to get a whole new wiring harness or BCM, I'm not sure it's worth it. I might just have to live with the lack of the handle button working. I'm guessing if I just took it in to the local shop, it'd be pricey.

Funny that you mention water intrusion. A while back, I noticed there was some water on the driver's side mat and carpet. I found a service bulletin for it, something about sealing the inner wheel well. I took a look in there, and it actually looked pretty good, but there may have been some gaps that weren't totally sealed. I put some sealer in there, and haven't noticed any leaks since. Also, the cowling at the lower part of my windshield doesn't always stay tight, so maybe water got in there? I don't have a sunroof, though. Anyway, that was all like a year or two back, and the door button just stopped working a few months ago. If I'm remembering right, it happened around the time I sprayed some really persistent bird poop off the driver's window with my hose. I wonder if some of the water could've leaked down? It's weird that it's only the button that crapped out, and nothing else in the door. Than again, that could all just be a coincidence. I guess I'm lucky that all the other locks and controls work. Just super annoying, though, because I used that dang button all the time.