Supersleeper
Posts: 18
Joined: Mon Aug 07, 2017 10:04 am
Delivery Date: 06 Aug 2017

Re: Easy Climate Control Fan-Only Solution - 5 cents, 5 mins

Sun Aug 13, 2017 12:16 am

So, did a search on the thread and was amazingly surprised no one has suggested doing method 2 with a simple push-button (always open unless depressed) "latching relay". This gives you simplified install while also working with timer control. The push button is only to engage the relay, that can only be powered while the car is on. That closes the circuit for the 330ohm resistor. When the power goes off, the relay disengages and you are back to stock wiring and ready to engage climate control timer. Way, WAY easier than method 3. You can also get fancy and buy an illuminated switch that is wired to the relay power to have a visual indicator of on or off.

If your not familiar with a latching relay, basically you use the 12v power that would be used to power the switch also loop through the relay switch and back to the coil +, that once engaged, keeps the relay on. The relay will not disengage until 12v supply is lost (car off). if you want to manually disengage the relay, you install a normally closed push-button switch that temporarily breaks the 12v supply to the relay. Normally closed push-button switches are always closed while disengaged, and broken only while your finger is depressing.

So effectively, you have the best of both worlds without the solder and loss of time.

GerryAZ
Gold Member
Posts: 1339
Joined: Mon Nov 22, 2010 6:47 pm
Delivery Date: 12 Jun 2011
Location: Phoenix, AZ

Re: Easy Climate Control Fan-Only Solution - 5 cents, 5 mins

Sun Aug 13, 2017 6:18 am

Supersleeper wrote:So, did a search on the thread and was amazingly surprised no one has suggested doing method 2 with a simple push-button (always open unless depressed) "latching relay". This gives you simplified install while also working with timer control. The push button is only to engage the relay, that can only be powered while the car is on. That closes the circuit for the 330ohm resistor. When the power goes off, the relay disengages and you are back to stock wiring and ready to engage climate control timer. Way, WAY easier than method 3. You can also get fancy and buy an illuminated switch that is wired to the relay power to have a visual indicator of on or off.

If your not familiar with a latching relay, basically you use the 12v power that would be used to power the switch also loop through the relay switch and back to the coil +, that once engaged, keeps the relay on. The relay will not disengage until 12v supply is lost (car off). if you want to manually disengage the relay, you install a normally closed push-button switch that temporarily breaks the 12v supply to the relay. Normally closed push-button switches are always closed while disengaged, and broken only while your finger is depressing.

So effectively, you have the best of both worlds without the solder and loss of time.


A sealed-in relay (not a mechanically-latched relay) would work as you describe, however you need to remember to depress the momentary pushbutton each time you start the car. The plug-and-play kit with 2 resistors and 3-position switch is a better and simpler solution if you want to make sure the heating element stays off unless you really want heat. The kit also gives two levels of heater temperature.
Gerry
Silver LEAF 2011 SL rear ended (totaled) by in-attentive driver 1/4/2015 at 50,422 miles
Silver LEAF 2015 SL purchased 2/7/2015

Supersleeper
Posts: 18
Joined: Mon Aug 07, 2017 10:04 am
Delivery Date: 06 Aug 2017

Re: Easy Climate Control Fan-Only Solution - 5 cents, 5 mins

Sun Aug 13, 2017 7:25 pm

GerryAZ wrote:A sealed-in relay (not a mechanically-latched relay) would work as you describe, however you need to remember to depress the momentary pushbutton each time you start the car. The plug-and-play kit with 2 resistors and 3-position switch is a better and simpler solution if you want to make sure the heating element stays off unless you really want heat. The kit also gives two levels of heater temperature.


I assume you mean solid-state relay? I haven't seen any switches that would have that built in, but I'd love to get my hands on one if they did exist. I just went ahead with a basic latching switch for now. I may later change to something else.

Yeah, I agree, if you are not electronically inclined, the harness is the best solution. I just can't see myself paying $150 for a cable, a resister and a switch. It's like $1.50 worth of material and 999% profit. It is worth the convenience to be able to revert to stock without having to tap into the wires, but this is a 6 year old car, and I personally don't care to revert to stock ;).

GerryAZ
Gold Member
Posts: 1339
Joined: Mon Nov 22, 2010 6:47 pm
Delivery Date: 12 Jun 2011
Location: Phoenix, AZ

Re: Easy Climate Control Fan-Only Solution - 5 cents, 5 mins

Sun Aug 13, 2017 10:38 pm

Since I rarely used the heater, I inserted a resistor directly into the connector under the hood and wrapped it with self-fusing tape to keep the heater from drawing power while using the air conditioner.

The kit I was referring to is the one by TorC (there is another thread about it) that costs about $20 US. The kit includes a harness with connectors on both ends that plug between the factory harness and HVAC controller so there is no need to cut into the factory wiring. I would have purchased the kit from TorC if my 2011 Leaf had not been totaled.
Gerry
Silver LEAF 2011 SL rear ended (totaled) by in-attentive driver 1/4/2015 at 50,422 miles
Silver LEAF 2015 SL purchased 2/7/2015

TorC
Posts: 70
Joined: Fri Jan 24, 2014 2:19 am
Delivery Date: 08 Mar 2013
Location: Sandefjord, Norway

Re: Easy Climate Control Fan-Only Solution - 5 cents, 5 mins

Tue Aug 15, 2017 12:17 pm

@ Supersleeper
Well, your idea is very good, and I have considered it in the past. One problem with the "method 2" (and my cable kit) is that you will not be able to use pre-heat with timer or App if the switch is engaged.

My solution to this is to simply use a N.O. relay connected to a switch both powered by the 12v outlet.

The switch will "remember" last setting, but will be inactive when the car is ON.

I do have a "plug and play" solution in the pipeline, but have been struggling for 9 months to get the correct connectors/terminals to the Nissan LEAF harness. I am now on the last possibility before I have to "backsource" the final assembly, but that will drastically increase the price due to local taxes and labor cost.

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