Cold inside. Heater on blink

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Joined
Nov 18, 2021
Messages
14
Hi. Bought our 2013 leaf 2 weeks ago and it's a dream to drive. Living in the North Scotland we need the heater on every day. It was working fine up until 2 days ago. I've been searching forums to find answers.

The blower still works so not the 12v fuse.
First thing I found was people having to replace heater
2nd thing was perhaps a rewire by nissan.

I have some mechanic friends and family so I'm hoping to fix it DIY. Is it possible the fluids need topped up?
 
Welcome to the forum. Is this one of the models equipped with the heat pump? I'm guessing that with zero heat it isn't. The likely suspects are either a blown resistance (PTC) heater fuse or a burned out PTC heater. If the fuse blew then the heater is quite possibly also bad. Let's hope that it's something less expensive, though. Ideas, folks?

Oh, and starting in 2013 there is no "coolant" used in the heater. It is a direct to air heater.
 
Would a blown PTC heater throw a code?

If you don't already have it, check out LeafSpy. It's an app that allows you to communicate with the OBDII port. Other generic OBDII readers can also read trouble codes so it might make sense to start there. But LeafSpy is truly the gold standard for OBDII on Leaf and it's not expensive.
 
So at last got round to meeting my mate who is diagnostics man. He plugged in his plug.

No fault codes present except 1.

B2631-00 Sunload Sensor CRNT

No indication that the heater circuit is broken or the heater ain't working.

Anybody know anything about this sensor and how it links to whether the heater runs or not?
 
The sun load sensor determines how strongly the A/C should run. I wouldn't be surprised, though, if it also affected heater output. Nonetheless, I wouldn't expect zero heat from a faulty sun load sensor. I do hope that I'm mistaken, for your sake. IIRC, the sensor is located in the top of the dashboard, or up by the mirror.
 
We seen the sunload sensor voltage and covered it up and seen the change.

We seen the temperature sensor was 32 Fahrenheit which would be zero Celsius. Which is just about right today's cold.

We also seen the heater output voltage was zero. As if its not there.

I was told to check the output signal from computer and input power to heater. I'm now hoping for a loose connection. What connections can I check? Where do I start? How do I check across the fuse and across heater without having to remove too much?
 
I am now looking through wiring and fuses under the bonnet. There is a control box to the left hand side.

nissan 284b7 3neoa

I want to get under this and see but the wiring harness holds it down. Can't find any information on Google.

Next I will pry out the sunload sensor see if it can be left out
 
90% sure it's your PTC heater. I just replaced mine a month ago after the same behavior as yours. Works great now, and the heat is nearly instantaneous. Here's the link to my DIY (with much help/input from the rest of this forum!). Not a terribly hard job, but make sure you don't shock yourself by not following power down procedures/etc. Good luck!

https://www.mynissanleaf.com/viewtopic.php?f=30&t=32447&start=10
 
Hello. I'm now away for 28 days. 22 more to go. Didn't repair it in time so wife is now driving around it cold north wind conditions.

I will change out the heater when I get home next time. My step brother who is our mechanic got covid just before I was going to borrow his garage.

Am I 100% sure it is the heater and not just a sensor or computer fault???

Where can I source a new or used good heater?

Thanks
Campbell
 
For used, try ebay, etc. For new, try a dealer. If getting used, be sure the seller knows how to test it or allows refunds.
 
Could be a sensor issue with your code, but 2013's with the original PTC heaters are all almost burned out (if they weren't replaced with the updated part). This doesn't really show up until the car calls for it to be turned on (think cold temps below what the heat pump can provide, and a high cabin temp).

Try this test.. look under Menu> Energy Info> Climate control (energy usage tab)... turn on the defrost to the highest setting. This should turn on the PTC heater regardless of whatever the sunload sensor is telling it. The kW on the climate control should spike between 3-4kW on initial turn on then taper off as it heats up (if your PTC heater is working). If you have zero kW.. more than likely, your PTC heater is fried.

There is a way to disconnect the HV power to the heater and test the impedance to see if it's ok (search this forum). I'd maybe try that first before pulling the trigger on a new heater if you're not 100% sure. Good luck!
 
I took the car to get refrigerant recharged. There qas only 10g and it was charged up to 450g. Still no change. Very cold and windy today. Cold car
 
We've just checked fault codes. Only 1 that came up was interior temperature sensor. So I will need to look up these sensors and change them next
 
Instrument panel lower Left Hand side--HAC manual page 197

It's an NTC thermistor where the resistance decreases as the temperature increases. if it is shorted or reading very low, then the control unit thinks the car is hot and no need for heat. A 5k resistor could be put across the connector terminals to simulate a temperature of about 40F.
 
Managed to get 2x 10k resistors and 2x 4.7k resistors from local computer repair shop. Didn't work immediately but I've disconnected the battery for 10 minutes and I will try again.

The refrigerant yesterday cost me 90 quid. So annoying that that wasn't the fault.

I think I may have to accept that it's the heater itself. Need to splash out on new spare.
 
If you had a DTC for the in-vehicle temperature sensor B2578 or B2579, then it might be worthwhile going thru the checks in the service manual HAC pages 100-105 to rule out possibilities?

2013 HAC

Maybe it is the PTC heater, but it has at least eight codes to identify faults,
B2770,2771,2772,2773,2774,
B2777, 2779, 277B
 
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