Air Flow Control: Description

WARNING: This page is about a different car, the 2019 Nissan NV3500 HD, 2019 Nissan NV2500 HD, and 2019 Nissan NV1500. However, it is still accessible from the selected car via links, so may be relevant.

The front air control provides voltage to the gate of the power transistor based on the position of the blower control dial. By applying a variable voltage to the gate, the power transistor controls the current flow to ground, thereby controlling the speed of the blower motor. The front air control monitors the blower motor voltage and the blower motor ground circuits. The blower control dial has 26 detents, each detent outputting a different gate voltage to the power transistor, allowing for 26 different fan speeds.

In addition to manual control of the air flow, the front air control will modify the customer selection during certain conditions. During heater warm-up, the front air control will move the intake door from fresh to partial recirculation. The front air control will illuminate the fresh indicator. Also, if the intake temperature is too hot, the intake door will move to partial or full recirculation. The front air control will illuminate the fresh indicator.

When the blower control dial is turned off, the front air control will remember the customer selected intake air position (REC or FRE), the current mode, and the A/C state. Upon turning to any blower speed, the front air control will return to the previous mode and state, and if the previous state was MAX A/C, the front air control will illuminate the REC LED.

Blower control dial detents	MAX A/C, VENT, and B/L	FOOT, D/F0	D/F1, DEF	P/REC Mode
OFF	0.00 volts	0.00 volts	0.00 volts	0.00 volts
1	3.25 volts	3.75 volts	3.75 volts	3.75 volts
2	3.50 volts	4.00 volts	4.00 volts	4.00 volts
3	3.75 volts	4.25 volts	4.25 volts	4.25 volts
4	4.00 volts	4.50 volts	4.50 volts	4.50 volts
5	4.50 volts	4.75 volts	4.75 volts	4.75 volts
6	4.75 volts	5.00 volts	5.00 volts	5.00 volts
7	5.00 volts	5.50 volts	5.50 volts	5.50 volts
8	5.25 volts	5.75 volts	5.75 volts	5.75 volts
9	5.50 volts	6.00 volts	6.00 volts	6.00 volts
10	5.75 volts	6.25 volts	6.25 volts	6.25 volts
11	6.25 volts	6.50 volts	6.50 volts	6.50 volts
12	6.50 volts	6.75 volts	6.75 volts	6.75 volts
13	6.75 volts	7.00 volts	7.00 volts	7.00 volts
14	7.00 volts	7.25 volts	7.25 volts	7.25 volts
15	7.50 volts	7.50 volts	7.50 volts	7.50 volts
16	7.75 volts	7.75 volts	7.75 volts	7.75 volts
17	8.00 volts	8.00 volts	8.25 volts	8.00 volts
18	8.25 volts	8.25 volts	8.50 volts	8.25 volts
19	8.50 volts	8.50 volts	8.75 volts	8.50 volts
20	8.75 volts	8.75 volts	9.00 volts	8.75 volts
21	9.00 volts	9.00 volts	9.25 volts	9.00 volts
22	9.25 volts	9.25 volts	9.50 volts	9.25 volts
23	9.75 volts	9.75 volts	10.00 volts	9.50 volts
24	10.25 volts	10.25 volts	10.25 volts	10.75 volts
25	10.50 volts	10.50 volts	10.50 volts	10.00 volts
26	10.75 volts	10.75 volts	12.00 volts	10.25 volts
12 = Max blower voltage