Blower Fan Doesn't Always Turn On - 2005 Sienna

[geebee2000]

I have a 2005 Sienna CE with 70K miles.

Lately when I use the AC, the blower fan switch does not always work.

The problem is intermittent. I took the car to a local shop and of course everything worked while at the shop.

But now when I turn on the AC and turn the fan switch to low, nothing happens. If I wait several minutes I can then turn the blower switch on and the AC will work.

I think that the blower switch is bad and I'm thinking of replacing it. I understand from my mechanic that if the resistor is bad than the fan will only work on high. That doesn't seem to be the case with mine. If the fan doesn't come on, changing the blower switch to the other setting including high doesn't make it work.
A friend said it might be a relay and we re-seated a relay marked "fan". The relay that we removed and re-seated is in the compartment under the hood where the fuses are. This seemed to have helped the problem temporarily, but then I realized that the relay marked fan may actually control the cooling fan, not the blower fan. I'm not sure.

Can anyone shed light on my problem?

[joesk]

my 2006 Sienna does not blow air out of the front vents for both heater and AC(rear fan works fine) I can turn on heater or AC for the rear seats but would not blow air in front. is there a fuse for front heater/ac blower fan? I could not locate one in the fuse boxes.

[Beekeeper2020]

Originally Posted by geebee2000

I have a 2005 Sienna CE with 70K miles.

Lately when I use the AC, the blower fan switch does not always work.

The problem is intermittent. I took the car to a local shop and of course everything worked while at the shop.

But now when I turn on the AC and turn the fan switch to low, nothing happens. If I wait several minutes I can then turn the blower switch on and the AC will work.

I think that the blower switch is bad and I'm thinking of replacing it. I understand from my mechanic that if the resistor is bad than the fan will only work on high. That doesn't seem to be the case with mine. If the fan doesn't come on, changing the blower switch to the other setting including high doesn't make it work.
A friend said it might be a relay and we re-seated a relay marked "fan". The relay that we removed and re-seated is in the compartment under the hood where the fuses are. This seemed to have helped the problem temporarily, but then I realized that the relay marked fan may actually control the cooling fan, not the blower fan. I'm not sure.

Can anyone shed light on my problem?

This problem is a relay problem, the relay for the fan is blue colored if I recalled.

Check it during the time it does not work by swapping.

What you can do is to swap the relay with the the same type by looking at the relay box in the engine compartment. Once you locate the relay that is bad, you can fix it by opening the relay and cut a #180 sand paper to clean the contact in between. If not you can just buy it, it cost ~ $18 from the dealers.

[Beekeeper2020]

Originally Posted by joesk

my 2006 Sienna does not blow air out of the front vents for both heater and AC(rear fan works fine) I can turn on heater or AC for the rear seats but would not blow air in front. is there a fuse for front heater/ac blower fan? I could not locate one in the fuse boxes.

Relay problem. The relay made by Toyota or OEM got problem. In the Engine compartment is where the fan is controlled by the relay. Clean the contact with sandpaper then the problem will go away.