Been using my '02 OBW in the snow a bunch lately, as here in denver(ish)...we've had a lot.

 

Car works incredibly well in the snow, of couse. But one thing: my rear defroster, as well as the heated windshield, turn themselves off after 10-15 minutes. It is not like a thermostat, since they never turn on again. Also, by hitting the buttons, I can turn them off immediately after they shut down. But I usually don't notice the dash lights on these two buttons have gone out; usually I notice that my window is icing up or the wipers are icing up.

 

Is this a feature, or a bug? If feature...WTF???

 

It's pretty annoying, for sure. Is this the way it's supposed to work? If not, what could be wrong?

Is this a feature, or a bug? If feature...WTF???

 

It's pretty annoying, for sure. Is this the way it's supposed to work? If not, what could be wrong?

Every car I've ever driven has had a timer-based cutout for the defroster. Keeps the wires from burning out prematurely. If it bothers you a lot, you COULD wire up some convoluted thermostat cutout, but that would involve a good bit of a new wiring. I'd guess that the timer is in the switch rather than the ECU, but who knows...

Right out of the owners manual ( pdf copy on Subaru.com )

 

The defogger will automatically shut off after about 15

minutes. If the window clears before that time, push

the switch to turn it off. It also turns off when the ignition

switch is turned to the “ACC” or “LOCK” position.

If defrosting or defogging is desired when you restart

your vehicle, you have to push the switch to turn it on

again.

To turn on the defogger, push the switch. To turn it off,

Been using my '02 OBW in the snow a bunch lately, as here in denver(ish)...we've had a lot.

 

Car works incredibly well in the snow, of couse. But one thing: my rear defroster, as well as the heated windshield, turn themselves off after 10-15 minutes. It is not like a thermostat, since they never turn on again. Also, by hitting the buttons, I can turn them off immediately after they shut down. But I usually don't notice the dash lights on these two buttons have gone out; usually I notice that my window is icing up or the wipers are icing up.

 

Is this a feature, or a bug? If feature...WTF???

 

It's pretty annoying, for sure. Is this the way it's supposed to work? If not, what could be wrong?

 

After 97 they all have it, before then some do some dont. The reason for it can be everything from fuel economy to protecting the glass.

My 1997 doesnt have it. There is a chance that the heat can affect the lamination of the rear window, but im just guessing. the timer in the relay costs money, so there must be a reason to put it there.

 

nipper

Ok then...I'm an idiot, since it's in the owner's manual and all. Odd, I've never driven a car with this feature (at least that I noticed).

 

I like that they shut off when the car shuts off, but apart from that, it'd be nice if they were rigged to a thermostat rather than a timer. Whatever. Thanks folks.

Ok then...I'm an idiot, since it's in the owner's manual and all. Odd, I've never driven a car with this feature (at least that I noticed).

 

I like that they shut off when the car shuts off, but apart from that, it'd be nice if they were rigged to a thermostat rather than a timer. Whatever. Thanks folks.

 

there was a discussion a while back about how nice this feature would be in the heated mirror circuits of the 95 - 98(?). the were a couple of reports of the drivers heated mirror is suspected of causing a fire in the door.

Most newer cars seem to do it. My '89 240SX cuts off at about 20 minutes. My mom's '05 Sentra is at about 15. My '81 hatch, '82 wagon, and '93 Loyale never turn off.

My '95 impreza doesn't have it and a few of the wires across the rear window have popped (like a fuse, no more continuity). This causes certain sections of the window to stay frozen.

I assume the timer is to correct this problem since the rear window is so expensive to replace.

My '04 impreza has the timer and I've yet to have a problem with the wires in the rear window.

My '95 impreza doesn't have it and a few of the wires across the rear window have popped (like a fuse, no more continuity). This causes certain sections of the window to stay frozen.

I assume the timer is to correct this problem since the rear window is so expensive to replace.

My '04 impreza has the timer and I've yet to have a problem with the wires in the rear window.

 

There are kits to repair the broken lines that work pretty well.

 

nipper