2011 Heater Core $1240 - Part B714300Q0A PTC - Alternatives?

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arnis said:
brycenesbitt said:
arnis said:
Buy a part from EBay or scrapyard.
Find somebody who will work at reasonable hourly fee. Be it 10 or 30$ per hour.
Half day job if you know what you do.

Update: purchased new used PTC core. Swapped it. No heat.

"new used" - so actually old and used.
Who said that it was functional before installation?

Yeah, back in the pre-Internets days I had an old Subaru that would intermittently stall. No one knew what was the problem, I was desperate and took it to a dealer who couldn't reproduce the issue but the tech said that it was likely the distributor, luckily I was able to walk away for free. A distributor was $600 new and no way I could pay that much for it but a local mechanic gladly installed a nice shiny "rebuilt" distributor at a fraction at that cost. I happily drove away only to get stuck again in a couple of blocks. Took it back, had them swap the old part back, went to a local junkyard that had a car on the lot like mine, paid $20 for the part after unscrewing it, installed it and never had that same issue since. So there is definitely a risk buying a used part.
 
Valdemar said:
arnis said:
brycenesbitt said:
Update: purchased new used PTC core. Swapped it. No heat.

"new used" - so actually old and used.
Who said that it was functional before installation?

Yeah, back in the pre-Internets days I had an old Subaru that would intermittently stall. No one knew what was the problem, I was desperate and took it to a dealer who couldn't reproduce the issue but the tech said that it was likely the distributor, luckily I was able to walk away for free. A distributor was $600 new and no way I could pay that much for it but a local mechanic gladly installed a nice shiny "rebuilt" distributor at a fraction at that cost. I happily drove away only to get stuck again in a couple of blocks. Took it back, had them swap the old part back, went to a local junkyard that had a car on the lot like mine, paid $20 for the part after unscrewing it, installed it and never had that same issue since. So there is definitely a risk buying a used part.

Luckily, where I live, used car parts often get very short warranty (1-2 weeks).
 
brycenesbitt said:
Update: purchased new used PTC core. Swapped it. No heat.

The PTC IGBT electronics is controlled by the A/C auto amp, so the auto amp, or
wiring could be at fault. Also there has been cases of when the PTC goes bad, it
also takes out a fuse in the DC/DC converter. In this case the DC/DC converter unit
has been replaced (Also a high cost item). There has been discussion of just replacing
the fuse, (which requires removing the DC/DC converter), but I am not aware of this
ever being done.
 
No wild speculation would be complete without mentioning that there were various ingenious mods to disable the heater on early LEAFs (given that the logic was a little stoopid when it came to running the heater any time the fan was on). Since the car was previously owned, ya never know. If the search was a little better here I might have found some of those threads. Sometimes there was a switch, and some schemes involved pushing the right combination of climate control buttons.

It also seems to me that the resistance part of the resistive heater ought to be measurable. Especially since it runs at 400 volts, there should be appreciable resistance (4 kW would dictate a 40 ohm resistance).
 
brycenesbitt said:
arnis said:
Buy a part from EBay or scrapyard.
Find somebody who will work at reasonable hourly fee. Be it 10 or 30$ per hour.
Half day job if you know what you do.

Update: purchased new used PTC core. Swapped it. No heat.

It was the fuse in this thread
http://gm-volt.com/forum/showthread.php?231521-2012-Nissan-Leaf-No-Heat#/topics/231521?page=1&_k=rk24ar
 
So I have the heater core out and on my desk.... and a pile of electrical test equipment.

...anyone have a schematic? Diagram? Ohm reading from a working heater "coil" (I know it's not a coil)?
 
Well PTC = Positive temperature coefficient as it heats it's resistivity goes up

Ohms law W/V
So 5,000W / 350V = 14.3Ohms cold apx so metering the main leads should be that

Most temp sensors are 10K NTCs they do the reverse their resistance drops as they warm, less common are 100k ntcs I'd be willing to bet it'd be one of those

Check for ground faults, any main lead should not register from the metal ground
 
XeonPony said:
so metering the main leads should be that
? But the PTC's are feed from pulses from the IGBT(maybe more than one),
so no direct connection from input high voltage. One would have to open
up the core and remove the circuit board that feeds the PTC's. Which may
mean un-soldering, or breaking a spot weld. to test the core would require
either building your own (maybe arduino) device to send control signals,
or maybe find a way of setting up the cars A/C auto amp to send the signals.
Can the core be opened up easily? I have seen a cut away showing the PTC's,
but not the circuit board.
 
The PTC unit is not hard to disassemble.... but looks to be a pain to get back together.
Actual measurements from working/dead units would help, not so much the speculation.
 
brycenesbitt said:
The PTC unit is not hard to disassemble.... but looks to be a pain to get back together.
Actual measurements from working/dead units would help, not so much the speculation.

Any final report?

The diagnostic/removal/repair/re-install manual for the 2012 can be found - HA and HAC manuals:
https://ownersmanuals2.com/make/nissan/leaf-2012-372

Take-away is that there are a number of possible problems not all related to the PTC heater itself.

Final question - I need a PTC unit (2011/2012) that does NOT have to be working - did you end up with one that you can sell me? If so, please PM me.
 
gbarry42 said:
No wild speculation would be complete without mentioning that there were various ingenious mods to disable the heater on early LEAFs (given that the logic was a little stoopid when it came to running the heater any time the fan was on). Since the car was previously owned, ya never know. If the search was a little better here I might have found some of those threads. Sometimes there was a switch, and some schemes involved pushing the right combination of climate control buttons.

Here is the link to that ingenious solution(s) to the PTC heater Illogic;

http://www.mynissanleaf.com/viewtopic.php?f=37&t=11412
 
Marktm said:
brycenesbitt said:
The PTC unit is not hard to disassemble.... but looks to be a pain to get back together.
Actual measurements from working/dead units would help, not so much the speculation.
Any final report?

Yes, a friend at a local EV friendly independent shop http://argonautgarage.com/ and I took the entire thing apart, found the bad fuse, and replaced it. The heater has worked since. I need to reinstall the disable switch, in part to limit the use of the heater core and presumably maximize it's lifetime.
 
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