I have plans to help a coworker try to figure out what is going on with his car's A/C, but I have no experience working on late 2000's Nissans, so I figured I would see if anyone has some tips and tricks that I need to be aware of.
The car is a 2007 Nissan Altima (base model) w/ ~ 120K miles
The problem is that upon entering car and starting the engine, it can take several minutes before the A/C starts to actually blow air out of the vents. It is not every time that this happens, but it does happen often enough, and it is hot enough here now, that it's become a real problem for him. And he knows as much about working on cars as I know about flying passenger jets, so I figured I could try to help him figure out what's wrong (or at the very least rule out some things as being the cause).
I did a cursory exam on it myself, and I see that it does not matter what the desired temp is or where it is set to blow air from. Cold or hot, A/C or heater, dash or floor, the issue will happen when it decides to happen. The lights on the control panel light up in response to my inputs on air speed, temp, etc., but there is no noise or air flow at all for a minute or two after starting the engine and commanding it to blow.
Previously he stated that once it did start to blow air, it would remain responsive to driver inputs the duration of the trip until engine shutdown. But just yesterday he stated the air started to shut off and restart itself during the middle of his drive. So whatever is wrong is getting worse it sounds like.
I have asked him to get a Chilton's manual to help lay out how to access the various HVAC components behind the dash, but I am not overly optimistic that it will be a huge help. I have noticed a downturn in their usefulness lately, with some editions being too generic to be of much help. So if anyone has some hints, tips, or tricks to pass along, they will be much appreciated.
Also, I figure the electronic control module that commands the blower motor is the best place to start. Hopefully I can test the output voltage it sends to the blower motor in response to commanded inputs. If that proves good (or I cannot sufficiently test it), I figure the actual blower motor itself would be the next suspect to rule out. I checked the underhood fuse box for the presence of a relay that controls the blower or A/C functionality, but I did not see one listed on the underside of the lid. There is an A/C fuse, but that is not blown or anything. What else can we look at as a possible suspect?
thanks,
nuke
The car is a 2007 Nissan Altima (base model) w/ ~ 120K miles
The problem is that upon entering car and starting the engine, it can take several minutes before the A/C starts to actually blow air out of the vents. It is not every time that this happens, but it does happen often enough, and it is hot enough here now, that it's become a real problem for him. And he knows as much about working on cars as I know about flying passenger jets, so I figured I could try to help him figure out what's wrong (or at the very least rule out some things as being the cause).
I did a cursory exam on it myself, and I see that it does not matter what the desired temp is or where it is set to blow air from. Cold or hot, A/C or heater, dash or floor, the issue will happen when it decides to happen. The lights on the control panel light up in response to my inputs on air speed, temp, etc., but there is no noise or air flow at all for a minute or two after starting the engine and commanding it to blow.
Previously he stated that once it did start to blow air, it would remain responsive to driver inputs the duration of the trip until engine shutdown. But just yesterday he stated the air started to shut off and restart itself during the middle of his drive. So whatever is wrong is getting worse it sounds like.
I have asked him to get a Chilton's manual to help lay out how to access the various HVAC components behind the dash, but I am not overly optimistic that it will be a huge help. I have noticed a downturn in their usefulness lately, with some editions being too generic to be of much help. So if anyone has some hints, tips, or tricks to pass along, they will be much appreciated.
Also, I figure the electronic control module that commands the blower motor is the best place to start. Hopefully I can test the output voltage it sends to the blower motor in response to commanded inputs. If that proves good (or I cannot sufficiently test it), I figure the actual blower motor itself would be the next suspect to rule out. I checked the underhood fuse box for the presence of a relay that controls the blower or A/C functionality, but I did not see one listed on the underside of the lid. There is an A/C fuse, but that is not blown or anything. What else can we look at as a possible suspect?
thanks,
nuke