My rear fan dont work when i connected the radio. My question are the fan work all time or have a temperature switch and work only at a fixed temperature ?

My old avic f900bt work all time. I just dont want overheat the unit at soso 1700$ because of shitty fan problem

Thx

It only runs when it needs to. That's from Pioneer tech line.

BTW this is good rather than bad design.

The reason is that cars are quite-high dust environments, and the dust tends to be pretty nasty too, not dry and easily-displaced. It's even worse if someone smokes in the car.

One of the worst issues with computers comes from the fact that their CPU fans run all the time.  This means you really need to open them up a couple of times a year and blow the heat sinks out with high-velocity air.  If you don't over time not only will the heat sink get clogged and become worthless but the fan will accumulate enough gunk on it to jam, overheat and fail.

I made an awful lot of money 20+ years ago replacing computers in offices where the workers smoked and the companies refused our service agreements that had us out there every six months cleaning all of them out claiming they were an unnecessary expense.  That was fine with me since I was perfectly happy to bill out the parts and labor to replace processors and power supplies instead, with those service calls coming on an emergency basis and thus being at our full hourly rate too.

With an audio amp once cooling impairment happens unless it's thermally protected you're screwed as it will burn up.

If the fan only runs when it needs to then the time before this occurs is materially lengthened.  I don't like forced-air cooling in this sort of environment at all but if you have to have it for heat dissipation reasons then using it only when required is a good thing.

Ok thx for the info i appreciate

I recieved and email direct from Pioneer on this question.