720inOlyWa Posted November 6, 2017 Report Share Posted November 6, 2017 My truck sounds like a 747 landing, when you set the fan on 4. But very, very little is actually coming out through the vents. I know this is wrong because on my other 720, the blower set to 4 will literally move the hair on my head.It has been recommended to me that perhaps crap has fallen down the air intake under the cowl, but when I looked down the tube, I saw nothing obstructing. I pulled the blower motor and felt around in there, but nothing was clogging up the works. I should note that my truck has A/C, so there is a cooling box next to the fan, and then the heater box, which is behind the console. Not finding a debris blockage, I figure that there must be a control flap shut or out of adjustment. At some point, somebody has already been here, replacing a heater core. I hesitated to post this thread before I removed the console and had a look at the fan controls. Flipping through all of the settings, everything seems to work fine. But clearly, air is not flowing freely out the vents. I have Haynes and a Nissan Service Manual for this vehicle, but neither goes into any troubleshooting details of the venting system. I thought that I would post here first in case there was a common 720 issue relating to air venting. Thanks in advance for any insights you can offer. 1 Quote Link to comment
720inOlyWa Posted November 6, 2017 Author Report Share Posted November 6, 2017 My truck sounds like a 747 landing, when you set the fan on 4. But very, very little is actually coming out through the vents. I know this is wrong because on my other 720, the blower set to 4 will literally move the hair on my head.It has been recommended to me that perhaps crap has fallen down the air intake under the cowl, but when I looked down the tube, I saw nothing obstructing. I pulled the blower motor and felt around in there, but nothing was clogging up the works. I should note that my truck has A/C, so there is a cooling box next to the fan, and then the heater box, which is behind the console. Not finding a debris blockage, I figure that there must be a control flap shut or out of adjustment. At some point, somebody has already been here, replacing a heater core. I hesitated to post this thread before I removed the console and had a look at the fan controls. Flipping through all of the settings, everything seems to work fine. But clearly, air is not flowing freely out the vents. I have Haynes and a Nissan Service Manual for this vehicle, but neither goes into any troubleshooting details of the venting system. I thought that I would post here first in case there was a common 720 issue relating to air venting. Thanks in advance for any insights you can offer. 1 Quote Link to comment
Crashtd420 Posted November 6, 2017 Report Share Posted November 6, 2017 From reading your post 2 things popped into my head... Does it blow any air in the 1 2 or 3 position ? Have you tested the fan itself outside of the housing? 1 Quote Link to comment
Crashtd420 Posted November 6, 2017 Report Share Posted November 6, 2017 Also since you have another 720.... try swapping the fans.... 1 Quote Link to comment
MaxChlan Posted November 6, 2017 Report Share Posted November 6, 2017 Maybe your air passages aren't lined up from blower to AC to Heater. Do you feel any air moving under the dash on the passenger side? That is an indication that those parts may not have a perfect seal on each other, which would really reduce the speed of the air coming out of the vents. Does your blower motor work on all settings? 1 Quote Link to comment
datzenmike Posted November 6, 2017 Report Share Posted November 6, 2017 Flap door is not set properly Heater core is now a mouse hotel Hose from fan to heater is now a mouse hotel Fan entrance in plenum is blocked 1 Quote Link to comment
blownalcohol Posted November 15, 2017 Report Share Posted November 15, 2017 I had the mouse hotel..... bummer it was 1 Quote Link to comment
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