Hi all,

Yesterday I installed an aftermarket radio in my son's 2017 Rogue. (base model). I purchased aftermarket harness adaptors for the steering wheel controls and backup camera. During the install and testing, I think I accidentally plugged the M50 Front Air Control into the aftermarket part that is the socket for the M87 Audio Unit adapter.

Now, the blower won't work on any speeds.

I did some searching here and can't find my situation.

Looking at the pinouts I found online, and comparing the pin functions, it's possible that I put 12V on MIX DOOR 2, and applied ground to FR FAN OUT, IGNW, and tied MCAN 2 L to 12V PROT MOTOR. But, I'm not sure if 1) they are 100% accurate (the M50 colors matched) and 2) if I need to "mirror" one since the layouts are depicted from the back of the connector. I did not remove the radio to verify color codes on M87 as it had gotten dark.

All the other functions controlled by the air conditioning panel work - the mix changes and doors change properly. None of the 3 fuses are blown (20, 17, and 27). Also, the steering wheel controls and factory backup camera work perfectly.

So some questions -

1) Is the 2016 service manual here close enough to the 2017? I'd like to double check my crossed pins.
2) What is required (beyond a voltmeter) to troubleshoot?
3) How can I see if the CANbus stuff is talking?
4) Should I just buy a resistor or amplifier for the blower now? How do I know which one?
5) Are there any other simple tests I've missed?

I'd like to get the defroster going again soon...

Thanks in advance.

Applying ground to the front fan control line very likely blew the driver in the AC Auto Amp. See if the voltage changes when you adjust the fan speed, if not you blew the driver. If the voltage still moves then you may have blown up the VBC (blower resistor) instead of the Auto Amp.

OK. Can I check the voltage at the blower with a standard multimeter capable of DC like my Fluke 373?

Is the 2016 manual suitable for the 2017? I just read those troubleshooting procedures starting on pg. HAC-176 and they seem straightforward enough. I didn't realize that individual voltages were produced with all 24 detents.

Yah, '17 is the same WD for those circuits, I checked for you. For '18~'20 they changed the HVAC Unit to use R1234yf instead of R134a, so the wiring is a bit different. The '16~'17 aren't identical across the board, but the blower control circuit is. The setup is way different for Auto versus Manual systems, so make sure you use the right WD.
Since the VBC is a PITA to access on both types, you'll want to check the PWM voltage at the control head. On an Auto system the head is separate from the display, it's called an A/C Auto Amp and it's located on the bottom of the HVAC Unit at the righthand front of the console. You're looking for a Gray wire on pin 67. On a Manual system the display and control head are integrated, you can just pop the display loose. You're looking for a Green wire on pin 1. In both cases, when you back-probe the wire and adjust the fan speed, you should see a "middle" voltage that changes with speed. If there's no change then chances are the driver is blown, but to make certain, remove the glove box and reach way up to disconnect the VBC (disconnect the 4-pin connector only if it's an Auto system). Then re-check. If the voltage from the control head now moves, then the VBC's gate is blown and it's dragging down the control voltage, replace the VBC. If you still see no movement with the VBC detached then the driver in the control head is fried.

Update:

Son and I started on Saturday working thru the troubleshooting guide, and of course Step 1 is check fuses. We pulled the first one, and it rang out on the multimeter, but showed 1.5 ohms resistance... We replaced it, and the blower started working.

(Edited to add- the fuse link is whole, but it did appear to have a burned spot in the very apex of the element. I've never seen that.)


It blew again this afternoon, so I'll continue with VStar650CL's advice I suppose... Thanks for the help!

There are always 2 blower fuses, a pair of 15A's in parallel. If they aren't both intact then the single good one will keep blowing.