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wbk
02-06-2017, 12:39 AM
Hi all -

I've read many threads and watched several youtube videos on fan blower issues. I have 2003 T1N. Here's my issue:

- Fan blower stopped working on any setting (0-4)
- When I turn on the AC via button (which indicated with red LED), the fan works
- But it's not very powerful and I prefer to use it without AC on since it's not very warm wheer i live
- When i turn off AC, the fan stops working immediately.
- I confirmed that the fan motor is working by visually inspecting while AC is on.
- I confirmed that recirculation on/off works and fan power is slightly better when recirculation on (as expected)
- I confirmed cabin air filter is clean and not causing lose of air pressure
- I took out the AC/power fan resistor and it looks fine. I ordered another one and will try swapping this out.

What is the coorelation between the fan working when AC is on but stopping whenever AC is off? This seems strange to me.

I've reviewed many of the threads online and learned a lot but none of them seem to indicate this relationship I'm seeing.

Thanks

Aqua Puttana
02-06-2017, 01:17 AM
..

What is the correlation between the fan working when AC is on but stopping whenever AC is off? This seems strange to me.

I've reviewed many of the threads online and learned a lot but none of them seem to indicate this relationship I'm seeing.

Thanks
The fan is powered to low speed automatically to help to avoid freezing the evaporator coil. If air isn't moving past the evap coil it gets too cold will freeze the condensation.

The A/C fan power is not part of the ATC fan speed switch control. Both the A/C and REST low speed provide power to the resistor pack without using the switch.

An alternate fan test is to enable REST with the key off. If the fan runs on low speed that indicates that the resistor pack is intact.

vic

autostaretx
02-06-2017, 02:43 AM
There are two fuses involved with driving the blower fan.
One feeds the A/C control panel, and if something (REST, AC, Aux Heater) is turned on, that circuit feeds the resistor and thus the fan.

The other fuse is the one that's engaged by setting the fan speed knob away from zero.
That fuse is number 21 on Fuse Panel #1, the one under the steering wheel. 30 amps.

So if it's the fan speed knob that's not doing anything, i'd look there for starters....
(shown on the upper left of this diagram... the Aux Heat, REST and AC come in from the triangle labeled "B" via connector C220)

82828

--dick