auggie721

Hi Everyone,
I just bought a 2003 IS300 last month and I absolutely love this car. There is a possible issue with the climate control system that I am hoping someone can help me answer. When I start the car in the morning, the fans will not turn on in auto or manual mode no matter what speed I select. The outside air temp is below 32 so I usually have the temperature dial cranked up to max. About 10-15 minutes into the drive I notice that the fans come on and operate as normal (both auto and manual mode). Is this by design or I do have something wacky going on with my fan controls?
thanks in advance!

Faymester

yea, that's normal ... your car cant warm up you until its warmed up

because the engine is cold and your car is using a lot of its energy to warm up the engine so you dont break it, your climate control system wont start pumping warm/hot air until the engine is sufficiently warmed up.

i'm not sure 10 - 15 min is normal though ... mine doesnt take that long, but i park inside ... it would be logical that the colder the engine, the longer to warm up ... so if u park outside that might have something to do with it

hope that made sense

auggie721

That explanation makes sense but I agree that 10-15 minutes is a bit long. So on the drive to work this morning I observed things more carefully and it took about 5 minutes to get up to operating temp. But to my surprise the fans did not come on at all for the entire drive. So I definitely think I have a problem with something like the blower motor control relay or a blown fuse.

I guess I cant complain too much. I could be driving in that artic blast going through Minnesota right now! If anyone has any experience with blower motors or related symptoms, I'd love to hear your experience. thanks!

lex pilot

Yeah, I have an ES300 (97) and sometimes the fan will not run unless I hold the increase button down. Then it goes to high untill I let off the button.
Sometimes it works right away ice cold and sometimes not.
I see in the troubleshooting guide there is an input from the coolant temp sensor into the ECM and a tap from there to the AC controller.
Is there a latching relay or a connection that is intermittent?
If anyone knows for sure if there is a temp limiter on the fan speed control, please post.

Carbon~IS

So it's not blowing any air when you turn the **** to auto... I don't think there is a temp limiter because mine will blow cold air for a couple of minutes, but it will still blow air out like crazy (especially on auto), but hot air will come out in 2-3minutes afterwards.