Electronic Climate Control Circuits
06-16-2004, 07:00 AM
#1
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Electronic Climate Control Circuits
This has been a pain in my a** since the first test drive of my Maximas. Seems that it's difficult to find one that works properly - has an accurate ambient temp. reading, all modes work, display works all the time, etc.
I've gone through 5 of them - one works for the most part, but the other 4 are in varying states of failing to failed completely.
My question is this - has anyone ever mapped the electronic climate control circuits? Does anyone know where I would find a circuit diagram? Or better yet...., does anyone know the exact part that fails and where it is on the circuit board(s)??
Basically I'm just fed-up with not knowing if I'll have a climate control system everytime I get in my car, or how long a working system will last me b4 I have to scoure the junkyards again to (hopefully) find a unit that works.
BTW - I'm not an electronics engineer, so if I 'map' the boards, the best I'll probably be able to do is figure out what areas of the board(s) control certain functions. I was after a little more specifics than that tho - hence this post.
I've gone through 5 of them - one works for the most part, but the other 4 are in varying states of failing to failed completely.
My question is this - has anyone ever mapped the electronic climate control circuits? Does anyone know where I would find a circuit diagram? Or better yet...., does anyone know the exact part that fails and where it is on the circuit board(s)??
Basically I'm just fed-up with not knowing if I'll have a climate control system everytime I get in my car, or how long a working system will last me b4 I have to scoure the junkyards again to (hopefully) find a unit that works.
BTW - I'm not an electronics engineer, so if I 'map' the boards, the best I'll probably be able to do is figure out what areas of the board(s) control certain functions. I was after a little more specifics than that tho - hence this post.
06-16-2004, 09:56 AM
#3
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All: Ambient temp reads -30 (celcius)
Current one in my silver car: only has vent, vent and floor, or floor modes - no defrost, no floor defrost. And the screen dims on occassion for no reason.
Current one in my black car: best one I have - everything BUT ambient temp works (for now anyway).
4th one: doesn't work AT ALL.
5th one: it's been awhile, but I think this one is the same syptoms as the one in my silver car - dims and only has a select few modes that work.
Current one in my silver car: only has vent, vent and floor, or floor modes - no defrost, no floor defrost. And the screen dims on occassion for no reason.
Current one in my black car: best one I have - everything BUT ambient temp works (for now anyway).
4th one: doesn't work AT ALL.
5th one: it's been awhile, but I think this one is the same syptoms as the one in my silver car - dims and only has a select few modes that work.
06-17-2004, 06:26 AM
#5
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Ya, 4 or 5 - can't really recall the exact number at this time? That's the reason for my post - I'd like to be able to diagnose these things myself in the future. You know, pull the board, and at least have a general idea which area to start probbing for a fault (depending on what isn't working at that time on that particular unit).
The problem isn't with the car itself - cause some of the units that don't work, or don't always work properly came from other cars just that way. I think it's more along the lines of the same reliability issues we all seem to have with out digital clocks - crappy engineering and/or electronic parts that fail too quickly. That's why I'm amazed no one knows how to fix these units ourselves?
I take it from the lack of replies that no one has 'mapped' these circuits yet?
Like I stated earlier, I'm not an electronics major, but I guess I'll at least make an attempt at figuring out what does what and what parts are required to make the repairs.
The problem isn't with the car itself - cause some of the units that don't work, or don't always work properly came from other cars just that way. I think it's more along the lines of the same reliability issues we all seem to have with out digital clocks - crappy engineering and/or electronic parts that fail too quickly. That's why I'm amazed no one knows how to fix these units ourselves?
I take it from the lack of replies that no one has 'mapped' these circuits yet?
Like I stated earlier, I'm not an electronics major, but I guess I'll at least make an attempt at figuring out what does what and what parts are required to make the repairs.
06-17-2004, 06:40 AM
#6
I wish I could help you with all of the problems but it sounds like to me you have a bad ambient sensor at least. If it reads incorrectly on all of them I am thinking it is the sensor. Maybe not but its worth a try.
That is the sensor behind the grille I believe.
Look on criags paige for the writeup. I believe he has the diags on there too.
That is the sensor behind the grille I believe.
Look on criags paige for the writeup. I believe he has the diags on there too.
06-17-2004, 10:18 AM
#7
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Location: Ontario, Canada
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Ambient shows -30 if it is not getting a signal from the thermoresistor on the post where the hood latch is located. I have just been through a repair of the sensor. It is a small black box that is sitting on the front of that post. Check conductivity from the harness of that box to the AC unit.
If the ambient sensor is not supplying the correct temperature, you can not expect the AC to work. In winter though you should feel pretty comfortable as the heater will be working at full speed.
If the ambient sensor is not supplying the correct temperature, you can not expect the AC to work. In winter though you should feel pretty comfortable as the heater will be working at full speed.
06-17-2004, 01:54 PM
#8
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Posts: 303
Not having pulled the board apart myself, but knowing a little bit about electronics, most of the circuits go to a processing chip which activates the motors to open air flaps etc. Electronic circuits are not the same as electric circuits which makes mapping the board harder.
Makes sense that if the processor isn't getting a reading from the ambient sensor, it will cause all sorts of problems for the chip, as the ambient sensor is the primary sensor that drives the unit. This probably explains why you have so many "fault" units and why each unit gives a variable amount of control.
Makes sense that if the processor isn't getting a reading from the ambient sensor, it will cause all sorts of problems for the chip, as the ambient sensor is the primary sensor that drives the unit. This probably explains why you have so many "fault" units and why each unit gives a variable amount of control.
06-18-2004, 06:47 PM
#10
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You know...., sometimes I make things harder than they really need to be... 
It never crossed my mind that the ambient temp sensor was dead!!?!?! I still don't think that will solve ALL the problems, but it's a worth a shot and I thank-you guys who mentioned it (awsm66, Tarzan and nismobaron). 
I'll definately check it out (when I figure out where it is - seeing as this will be the first time I've looked for it - you might see a "where is the sensor?" thread in a few days...
Seriously tho - it's behind the front grille? Top? Bottom? Left? Right? (I'm sure I can find it - just thought I'd ask since we're on the topic anyway...).
FNG, ya I'm from London. The Maxima scene isn't all that strong here, but I try to do my part. Hopefully my new black Max will be better to me than my silver one has tho. I expect it will tho - I've already changed the oil, oil filter, fuel filter, pcv valve, spark plugs (NGK Iridiums), cap & rotor, added a K&N direct replacement air filter (for now...), replaced a front wheel bearing, rebuilt the passenger rear wheel well (was just starting to go).
It passed the safety today - just needed a headlight.
It also passed the e-test with flying colors - needed a gas cap. And that's with 314,000 kms!!
Next week I'm putting the Intrax springs on it and my polished stainless-steel exhaust with dual DTM style tips.
It never crossed my mind that the ambient temp sensor was dead!!?!?! I still don't think that will solve ALL the problems, but it's a worth a shot and I thank-you guys who mentioned it (awsm66, Tarzan and nismobaron). I'll definately check it out (when I figure out where it is - seeing as this will be the first time I've looked for it - you might see a "where is the sensor?" thread in a few days...
Seriously tho - it's behind the front grille? Top? Bottom? Left? Right? (I'm sure I can find it - just thought I'd ask since we're on the topic anyway...).
FNG, ya I'm from London. The Maxima scene isn't all that strong here, but I try to do my part. Hopefully my new black Max will be better to me than my silver one has tho. I expect it will tho - I've already changed the oil, oil filter, fuel filter, pcv valve, spark plugs (NGK Iridiums), cap & rotor, added a K&N direct replacement air filter (for now...), replaced a front wheel bearing, rebuilt the passenger rear wheel well (was just starting to go).
It passed the safety today - just needed a headlight.
It also passed the e-test with flying colors - needed a gas cap. And that's with 314,000 kms!!
Next week I'm putting the Intrax springs on it and my polished stainless-steel exhaust with dual DTM style tips.
06-18-2004, 07:49 PM
#11
its right in the center of the grille. I believe right below where the grille clip goes. Its just a square box with wires coming out.
take the grille off and you cant miss it.
Good luck...It will not solve all your problems but will probably solve the incorrect reading.
take the grille off and you cant miss it.
Good luck...It will not solve all your problems but will probably solve the incorrect reading.
06-19-2004, 02:19 AM
#12
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Posts: 491
Qoute Shvelle:
FNG, ya I'm from London. The Maxima scene isn't all that strong here, but I try to do my part. Hopefully my new black Max will be better to me than my silver one has tho. I expect it will tho - I've already changed the oil, oil filter, fuel filter, pcv valve, spark plugs (NGK Iridiums), cap & rotor, added a K&N direct replacement air filter (for now...), replaced a front wheel bearing, rebuilt the passenger rear wheel well (was just starting to go).
It passed the safety today - just needed a headlight.
It also passed the e-test with flying colors - needed a gas cap. And that's with 314,000 kms!!
Next week I'm putting the Intrax springs on it and my polished stainless-steel exhaust with dual DTM style tips.[/QUOTE]
Have you been to TorontoMaxima.com yet? Those guy's are a great bunch of screwballs keeping the maxima scene alive around us. Unfortunately I always seem to be busy when they get together. If it wasn't for the 3 hour drive, it wouldn't be an issue.
FNG, ya I'm from London. The Maxima scene isn't all that strong here, but I try to do my part. Hopefully my new black Max will be better to me than my silver one has tho. I expect it will tho - I've already changed the oil, oil filter, fuel filter, pcv valve, spark plugs (NGK Iridiums), cap & rotor, added a K&N direct replacement air filter (for now...), replaced a front wheel bearing, rebuilt the passenger rear wheel well (was just starting to go).
It passed the safety today - just needed a headlight.
It also passed the e-test with flying colors - needed a gas cap. And that's with 314,000 kms!!
Next week I'm putting the Intrax springs on it and my polished stainless-steel exhaust with dual DTM style tips.[/QUOTE]
Have you been to TorontoMaxima.com yet? Those guy's are a great bunch of screwballs keeping the maxima scene alive around us. Unfortunately I always seem to be busy when they get together. If it wasn't for the 3 hour drive, it wouldn't be an issue.
06-19-2004, 06:00 AM
#13
check out my webpage on the climate control conversion, it'll show you all the pieces
also, there is a diagnostic you can run to test out different sensors and motors. It's in the service manual and paraphrased on my site too
www.geocities.com/craigbrace
also, there is a diagnostic you can run to test out different sensors and motors. It's in the service manual and paraphrased on my site too
www.geocities.com/craigbrace
06-19-2004, 06:45 AM
#14
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Join Date: Jan 2004
Posts: 610
I have problems to and i thought it was the Unit. i can only blow on HIGH w/ the ACC it's my fan control amp.....Craig anyone? does that sound right? and also does anyone have a pic? The FSM does not justice on telling me what thise peice looks like. also does anyone else have this extra? because cloest dealer is about an hour of so away and i dont need anything else from them.....and no junk yards around here have nissans just hondas
06-21-2004, 06:22 AM
#16
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Thanks again for all the input guys! I've been very busy lately, but I'll definately get to fixing the sensor soon.
FNG - ya, I've been to the TO site, but never been to any meets (yet). My silver car was too far gone for me to ever feel comfortable taking to one... I may make it out to one this year, but can't be sure as I have a bunch of house renovations and cars to fix (mine and others).
FNG - ya, I've been to the TO site, but never been to any meets (yet). My silver car was too far gone for me to ever feel comfortable taking to one... I may make it out to one this year, but can't be sure as I have a bunch of house renovations and cars to fix (mine and others).
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