QueenBee wrote:A local 2011 LEAF had the AC compressor short to ground which blew the fuse in the DC/DC junction box and the battery junction box. They aren't getting it repaired by the dealer as it'll cost as much/more as the car is worth. So looking through the service manual sounds like a fun enough project. What I'm curious about is if anyone has attempted to repair these two fuses? It's not dealership serviceable but it'd be a little disappointing if these really weren't replaceable by someone with a bit of electronics skill.
QueenBee wrote: What I'm curious about is if anyone has attempted to repair these two fuses? I
cliff wrote:QueenBee wrote: What I'm curious about is if anyone has attempted to repair these two fuses? I
I have not, however here is a link to a picture of the fuses in the DC/DC junction box.
http://www.marklines.com/img/report/en/ ... _014_l.jpg
I see there is a 4th fuse in the picture in addition to the 3 that are clearly tied
to high voltage.
QueenBee wrote:A local 2011 LEAF had the AC compressor short to ground which blew the fuse in the DC/DC junction box and the battery junction box.
cliff wrote:QueenBee wrote:A local 2011 LEAF had the AC compressor short to ground which blew the fuse in the DC/DC junction box and the battery junction box.
Thinking about this, a short to ground should not have done anything. One of
the main safety features of the Leaf is that neither side of the battery is connected
to ground(somewhat like power in a hospital). So the positive must of shorted to
the negative, but only the positive had a fuse to protect the wire, so what
happened to the negative? With the fuse in the battery box going, this would
suggest to me that the negative could have taken more current than it should
before the fuse went. Is this a design error not having a fuse on the negative
side? But once the positive fuse went, then why did the other fuse go?
The 3 fuses in the DC/DC junction box are all 30 amp fuses, to the heater,
charger, and compressor. the 4th fuse is a 15 amp for the converter.
GerryAZ wrote:If the compressor circuit failed one leg to ground and then the other leg to ground, the other fuses could see short circuits and blow (depending upon where the grounds were in relation to the fuses and main contactor). The DC ground detection system would try to open the main contactor to isolate the battery as soon as it detected the first ground, but fuses would blow if the grounds became short circuits quickly. Have you checked the main contactor and insulation to ground of all high-voltage wiring? Good luck with your repairs.
JeremyW wrote:Looks like you got it all settled before I wandered in, QueenBee. I would do the same thing, swap the dc/dc junction box and then teardown the dead one.
It's not clear to me, but I suspect the only the fuses in the dc/dc junction box are blown. In the 2011-2012 cars, the main pack fuse is in the orange disconnect that is in the backseat footwell. Does the car otherwise start and drive without AC?
The 2013+ cars have a different "HV junction" setup, and thus the 2013 service manual wouldn't be much help, Electric Eddy. At any rate, Nissan does module swaps and wouldn't have a normal tech replace fuses in the dc/dc. For example, we've seen the same with 2011-2012 chargers and diode issues: they always just replace the entire charger.
The high voltage side of the A/C compressor shorted to ground and blew the fuse in both the junction box internal to the battery and the fuse inside the DC/DC converter.