Heater blower: air trickles out the vents??

**C-speed** · 04-05-2008, 13:19

Hey guys,
Kind of got a strange problem... searched through all the related blower threads I could find, but it doesn't seem like anyone has the same problem.

On my NSX, even if I set the fan speed to high, the air kinda trickles out the vents... You'd expect the air to come rushing out with some force. The CCU diag says the CCU and control motors are working 100% and doesn't give any errors.

I can hear the blower fan change speeds from low to high, and it certainly makes more noise (spinning faster) when set to high, and a little more air does come out the vents, but not drastically. The difference in the amount of air that comes out the vents from low speed to high speed, is minimal.

I looked in the Helms and it doesn't appear to have a filter on the blower, so could there possibly be debris or something blocking the inlet perhaps?

Anyone have any suggestions? Thanks!

**Briank** · 04-06-2008, 17:44

The first thing I would do would be to pull off the cover on the cowl and look into the intake of the blower with a flash light and see what I could see.

**GreyHoundSteve** · 04-07-2008, 16:45

I'm no mechanic but i have heard that if the system is overcharged that it can freeze up and not work like it should. Have you recently had your system charged?

**drew** · 04-07-2008, 17:56

I think I might have the same or very similar problem: The heat and/or cold just trickles through. I'm not getting a lot of flow out of the center vents in any event.

I get no heat flow unless I hit defrost too. Otherwise the air IS hot, but it doesn't flow out of the vents.

This problem manifested itself after I changed out the evap and sent out the CCU for repair at the same time. So I have no idea what to drill down on.

I've been working with BrianK on a Q&A session, but no great leads yet.

I am leaning toward the interior temp sensor, heater control valve actuator (which also activates internal baffles) and the CCU.

Drew

**C-speed** · 04-07-2008, 22:12

Originally Posted by GreyHoundSteve

I'm no mechanic but i have heard that if the system is overcharged that it can freeze up and not work like it should. Have you recently had your system charged?

No, this has nothing to do with the A/C or if its on or off... its simply a matter of air flow coming from the vents when the fan is on low through high.

**C-speed** · 04-07-2008, 22:14

Originally Posted by drew

I think I might have the same or very similar problem: The heat and/or cold just trickles through. I'm not getting a lot of flow out of the center vents in any event.

I get no heat flow unless I hit defrost too. Otherwise the air IS hot, but it doesn't flow out of the vents.

This problem manifested itself after I changed out the evap and sent out the CCU for repair at the same time. So I have no idea what to drill down on.

I've been working with BrianK on a Q&A session, but no great leads yet.

I am leaning toward the interior temp sensor, heater control valve actuator (which also activates internal baffles) and the CCU.

Drew

Ya, mine is very similar... its almost as if there is a clog in the system that is blocking the air. I can hear the flaps move and change positions, the air blows hot and cold depending on the temp setting, the CCU doesn't give any errors, yet the air flow SUCKS when set to high.

I'm stumped.

**drew** · 05-19-2008, 20:04

After a long bit of testing, I have concluded that these issues are caused by a problematic CCU.

After weeks of testing, measuring and swapping parts: another CCU solved the problem. I even went so far as to swap out the CCU display...the problem most definitely lies within the controller board.

I'll be sending my problem CCU to Brian for his diagnosis.