'07 M35 Climate Control issue [SOLVED - blower relay usually]

[velveteendad]

I have a 2007 M35 with 58k miles on it, and am having an intermittent problem with the climate control that I'm wondering if others have experienced and have suggestions on how to address.

The climate control works, but it frequently takes a long time to go on - much longer than it takes for the car to warm up. Sometimes the blower will go on very quickly, as it did when it was working properly, but other times it'll take 20 minutes before it goes on. When it's not going on, pushing the fan button doesn't do anything, but once the blower has gone on, the fan button does control it properly - it will blow stronger or softer based on the level that I've set it at.

It doesn't seem to be a problem with the compressor, because even when the fan isn't on the air that's coming through the vents (just being pushed through from driving) is cold.

The dealer diagnosed it as needing a new blower motor and a new fuse box, at a cost of $940. But I pointed out that the blower motor works fine once it goes on, and that it's just a matter of it taking a while to go on. So they're saying that we should try replacing the fuse box at a cost of about $470 and see if that fixes it. They say that if that doesn't work, the next step will be to replace the blower motor, even though it does work.

Has anyone experienced something like this, and any suggestions for getting it properly diagnosed before spending $470 (or $940!) on something that might or might not work? Given that the system DOES work at times, it seems questionable that replacing the fuse box would be the solution, either.

Thank you.

[DeanM45]

I would find a new dealer. Fuse box? That would be extremely easy to diagnose with a VOM. It sounds more like a problem with the a/c amplifier. There should be no more than a 150 delay before the fan kicks on in auto mode when starting the car and that long of a delay is only in really cold situations.

[nubian67]

CAn you elaborate on the A/C Amplifier theory? Having the same problem and dont really want to take it to the dealer. There are at least three other posts on this forum on this same exact problem. No fixes yet.

[movado750]

Here is your fix. I had the same problem last year and was just thinking yesterday how many other people have it too. Low and bold hold just got a email today from a member.

Re: No heat when the vehicle in idle. (2006 m35x)
by mcalvino45 » Thu Jan 19, 2012 7:05 pm
If that sounds like your problem, get part #25230-79942 (dont worry about the vehicle description) and you can sleep good tonight your problem is solved...if you can tell me how to attach a photo I will send you a couple or just send me your email address.

[DeanM45]

CAn you elaborate on the A/C Amplifier theory? Having the same problem and dont really want to take it to the dealer. There are at least three other posts on this forum on this same exact problem. No fixes yet.

I would try the relay (listed above) and see if that fixes your problem.

The A/C amp takes all the inbound signals (switches, temp sensors, pressure sensors, etc.) and "tells" which component to kick on. Again, the dealer should have been easily able to diagnose this with a volt ohm meter.

It did not dawn on me during my earlier post (only had the car for a month) that there would be a relay to supply 12V to the blower resistor/motor. Try the relay first.

[velveteendad]

In my case, I let them replace the fuse box but told them not to replace the blower motor. Replacing the fuse box fixed the problem. Cost was about $450 instead of $900.

[infiniti650]

Adding to an old, but valuable thread...

So my '07 M35 started having intermittent issues as well with the blower/fan in all modes - Auto, defrost, manual fan. Googling around, found the old threads about a Blower Fan Resistor on older (generally pre-2006) nissan/infinii. Then this thread, and one about a G35 on another forum. Long story short. These "newer" nissan/infiniti have a relay for the blower fan instead. And it is a good place to start, because it isn't so bad to replace.

Because of the centralized/integrated climate control on these cars, it may be something else, i.e. there are 4 or 5 sensors in the car to determine temperature, ambient temperature as well as tying into the heater core thermostat, so it might be something else, but the relay seems to often be the culprit. In my case, my fan might come on when the engine heated up sometimes, but it would just as often not work, when the engine was hot, which is why I didn't believe it was the heater/coolant thermostat.

Sorry no pictures, but using the FSM on Nico and the index (idx.pdf) and searching for interior fuse block, blower fan relay, front kick/kicking plate was enough to find necessary info. So the procedure was:
- Buy a blower relay: 25230-79942 , same part number for Nissan and Infiniti. I got it for $35, but there are generic for $25-30
- Find your interior Fuse Box/Block. On 2007 M35, it down by the driver's left leg, left of the parking brake
- There is single, black nut, just above the dead foot pedal. Remove it.
- Now the rest are snaps
- Remove the Sill Plate (has lit infiniti on it). Nissan/infiniti calls it a Kick Plate, or Kicking Plate; it is L shaped and holds down carpet. There are 3 snaps - top left, middle, back right, as you face into car. You lift up. I used a screwdriver to pry it up. Have to pull fairly hard.
- Once you remove that, then you can remove the carpet/plastic cover over the fuse block. 2 more snaps on side opposite of screw. "pull" towards interior of car.
- With that out of the way, you can now contort yourselft to remove the Fuse Block/box. There are 2 screws/bolts on top. Don't remove the screws underneath; they're for box under Fuses. On the bottom of the Fuse Block, it slides over a metal plate with a plastic tab. Need to use a screwdrive to pop tab, and wiggle Fuse block out. Tip: I used a socket wrench to remove bolts. If you put some tape into the socket, it will hold bolts and not drop them as you take them out, and put them back
- With Fuse Block pulled out a bit, you can turn it over. For the M35, on the back of the Fuse Block there are 2 blue relays, the blower relay is the furtherest one back, or on the "right" as you are facing the Fuse side of the Fuse Block. if you check your Fuse diagram, the relay is behind the 2 15Amp fuses labeled Fan on the fuse diagram.
- you can wiggle/pull out the blower relay. No tabs, but will take some wiggling.
- Replace with new relay. Then start your car, and test the Climate Control. It all worked.
- Now just put everything back, and you're done
- Took about 20-25 minutes to take everything out, since I was moving slow and careful. About 5 minutes to put it all back together again.
- Tools used: screwdriver, metric socket, socket extension, socket wrench.

[Ilya]

Adding to an old, but valuable thread...

So my '07 M35 started having intermittent issues as well with the blower/fan in all modes - Auto, defrost, manual fan. Googling around, found the old threads about a Blower Fan Resistor on older (generally pre-2006) nissan/infinii. Then this thread, and one about a G35 on another forum. Long story short. These "newer" nissan/infiniti have a relay for the blower fan instead. And it is a good place to start, because it isn't so bad to replace.

Because of the centralized/integrated climate control on these cars, it may be something else, i.e. there are 4 or 5 sensors in the car to determine temperature, ambient temperature as well as tying into the heater core thermostat, so it might be something else, but the relay seems to often be the culprit. In my case, my fan might come on when the engine heated up sometimes, but it would just as often not work, when the engine was hot, which is why I didn't believe it was the heater/coolant thermostat.

Sorry no pictures, but using the FSM on Nico and the index (idx.pdf) and searching for interior fuse block, blower fan relay, front kick/kicking plate was enough to find necessary info. So the procedure was:
- Buy a blower relay: 25230-79942 , same part number for Nissan and Infiniti. I got it for $35, but there are generic for $25-30
- Find your interior Fuse Box/Block. On 2007 M35, it down by the driver's left leg, left of the parking brake
- There is single, black nut, just above the dead foot pedal. Remove it.
- Now the rest are snaps
- Remove the Sill Plate (has lit infiniti on it). Nissan/infiniti calls it a Kick Plate, or Kicking Plate; it is L shaped and holds down carpet. There are 3 snaps - top left, middle, back right, as you face into car. You lift up. I used a screwdriver to pry it up. Have to pull fairly hard.
- Once you remove that, then you can remove the carpet/plastic cover over the fuse block. 2 more snaps on side opposite of screw. "pull" towards interior of car.
- With that out of the way, you can now contort yourselft to remove the Fuse Block/box. There are 2 screws/bolts on top. Don't remove the screws underneath; they're for box under Fuses. On the bottom of the Fuse Block, it slides over a metal plate with a plastic tab. Need to use a screwdrive to pop tab, and wiggle Fuse block out. Tip: I used a socket wrench to remove bolts. If you put some tape into the socket, it will hold bolts and not drop them as you take them out, and put them back
- With Fuse Block pulled out a bit, you can turn it over. For the M35, on the back of the Fuse Block there are 2 blue relays, the blower relay is the furtherest one back, or on the "right" as you are facing the Fuse side of the Fuse Block. if you check your Fuse diagram, the relay is behind the 2 15Amp fuses labeled Fan on the fuse diagram.
- you can wiggle/pull out the blower relay. No tabs, but will take some wiggling.
- Replace with new relay. Then start your car, and test the Climate Control. It all worked.
- Now just put everything back, and you're done
- Took about 20-25 minutes to take everything out, since I was moving slow and careful. About 5 minutes to put it all back together again.
- Tools used: screwdriver, metric socket, socket extension, socket wrench.

Excellent first post, sir! Many people (members and Google searching non-members) will find this information very useful.

[infiniti650]

Thanks! Just trying to give back a bit. Nico has been a great resource over the years (for both this car and our previous Maxima), especially the FSM.

[M35xDriver]

Adding to an old, but valuable thread...

So my '07 M35 started having intermittent issues as well with the blower/fan in all modes - Auto, defrost, manual fan..............

First of all, glad to see this thread isn't ancient, so it doesn't appear I'm adding to something from long, long ago...

This is exactly what mine is currently doing, which started about 2 weeks ago (I have an 07 M35x)...I've ordered the part (Amazon - $25) and have printed out the instructions...Gonna give this a shot...30-45 minutes and $25 isn't much to overcome even if this doesn't do the trick...But, if it does, it's a big time and money saver in the long run...

Bought mine this past summer but AC always worked without issue...Now that winter is upon us (14 - 18 degree nights of late), having no heat the past couple weeks in the early morning hours, even after driving 30+ minutes, is a bummer...

Once I get the part, I'll update the thread...

Thanks again for the instructions and part number...Oddly enough, even after calling 2 local Infiniti dealerships in my area, they both stated they had no idea what the part number could be...

[The00Dustin]

Bought mine this past summer but AC always worked without issue...Now that winter is upon us (14 - 18 degree nights of late), having no heat the past couple weeks in the early morning hours, even after driving 30+ minutes, is a bummer...

Can you manually turn the blower up to full blast? If you can and the air is cold, then this is very unlikely to be your problem. In that case, you probably need to review some of the other threads on this forum about engine coolant and/or heating issues. I think the most common reasons for not getting heat in ANY car are bad thermostats (flowing coolant keeping the engine from warming up when the thermostat should be preventing the flow) and bubbles in the coolant (keeping the coolant from flowing through the heat exchanger even if the thermostats are open).

ETA: Also possibly even simply a low coolant level in the radiator, maybe some other things, definitely review threads about heat instead of climate control if the fan is working right.

[M35xDriver]

I apologize for the hiatus, as I stated I would visit again with an update...Alas, work had me pinned for a while...

@The00Dustin

It did not matter if I manually turned the blower to full blast, as the blower itself would not push any air...Well, that's not entirely true as it was really a coin flip as to if the blower would work at all...Sometimes it would, but many more times than not, no air would be pushed...If it did, it seemed the blower would only start pushing air after about 30 minutes of driving...By that time, if no air was getting pushed, it wasn't going to happen...

In regards to the latter part of your post, just a week before I had the thermostat changed as well as a total coolant flush...It was due for this anyway so I didn't mind moving forward with that part of the troubleshooting...Unfortunately, nothing changed...

*******

Now, after receiving the relay switch ($25), I replaced it in about an hour...Before putting the fusebox, screws and panels back in, I fired up the car and the blower immediately started working...I gave it a few minutes and warm air started to get pushed...Each and every time since then, everything is working fine...So, in my case, the $25 part was indeed the issue and the blower is pushing air hot and cold as I've tested both...

Again, I appreciate the directions...And yes, that relay switch was a bit of a pain to get out, but the deed is done and I'm warm in the wee hours of the morning again...

[raydecea]

Hi, I had the same problem with my 06 m35. I knew it was a temperature related problem as warmer weather would make the fan work less intermittently. I got lazy and used a hair drier to heat up the fuse box for about a minute in cold weather to get the fan to come on. My wife complained and asked me to fix the thing. I ordered the relay 25230-79942 and spent about an hour on my side under the foot pedals ( 66 years old ) to get the fuse panel out and replace the relay. All is good now. It took a 11mm socket with a 6 inch extender to remove the two nuts at the top left and right of the panel and then pull it out. You can try the drier method or just replace the part. I found it on amazon for $25.00