L3540 HSDCC Rear Window Defrost

[Kubotafan]

I have a L3540 Cab tractor with the electric defrost in the rear and corner glass. The tractor is used for snowblowing, and often times the snow is blowing back on you so the heated glass is a must to keep the snow melted and keep it for fogging up inside. The problem is that the power switch has a built in timer, so about every ten minutes it shuts off automatically, and I don't notice it until it starts fogging up on the inside. I suspect a regular switch could be used that would keep it on until it was shut off. Any problem with doing this, and what amp rating would I need on the switch?

 

[4shorts]

I have a L3540 Cab tractor with the electric defrost in the rear and corner glass. The tractor is used for snowblowing, and often times the snow is blowing back on you so the heated glass is a must to keep the snow melted and keep it for fogging up inside. The problem is that the power switch has a built in timer, so about every ten minutes it shuts off automatically, and I don't notice it until it starts fogging up on the inside. I suspect a regular switch could be used that would keep it on until it was shut off. Any problem with doing this, and what amp rating would I need on the switch?

It's something I never use. For one it does a terrible job keeping the glass from frosting up. For two its draws a lot of power. If you want to keep your windows clear just turn on the AC button and turn on the heat. Problem solved :thumbsup:

 

[Bob77064]

It's something I never use. For one it does a terrible job keeping the glass from frosting up. For two its draws a lot of power. If you want to keep your windows clear just turn on the AC button and turn on the heat. Problem solved :thumbsup:

That method works in the truck also.

 

[WaxMan]

It's something I never use. For one it does a terrible job keeping the glass from frosting up. For two its draws a lot of power. If you want to keep your windows clear just turn on the AC button and turn on the heat. Problem solved :thumbsup:

Not only that, it doesn't look that great on the glass, sorry, my comments aren't meant for the owners of the heat strips. It was meant for the people who are deciding whether or not to get the tractor with the expensive heated glass option. I have never once had a defrost problem and I have been out in every storm this winter. And we had a few.

But then again to be honest, I do not have a rear blower. So take that into consideration.

 

[Kubotafan]

It's something I never use. For one it does a terrible job keeping the glass from frosting up. For two its draws a lot of power. If you want to keep your windows clear just turn on the AC button and turn on the heat. Problem solved :thumbsup:

I use the A/C and heat but still use the defrost. I can tell when it shuts off as it isn't long before I start to see it fogging. It is worse without the A/C.

 

[coldfingers]

Never thought about using the ac in the tractor for that, thanks guys!

 

[dstig1]

I find I need my defrosters in some weather conditions, AC or no, especially with long plowing runs. Keep in mind that AC does not cycle on below 30-40F as the pressure in the system is too low to trip the LP cutout switch, so you really get no AC when it is reasonably cold...whether the light is on or not. I'm very glad I have them, and I got the side defrosters too. Not sure those were needed as much, but the rear sure is. The sides help a little at least, but not as critical. I do notice the fogging in the sides first though, which is my clue to hit the button (or hit it again). But then with -20F temps this winter I may be in a different boat than other posters here (though not the guy from Warren, MN...). My $0.02

BTW there is a defogger relay which may have the timer in it instead of the switch. It wasn't noted in the schematic that there even was a timer, though there obviously is somewhere. Not sure, but I agree it would be nice to have it at least run a longer cycle, as it is too short.

 

[4shorts]

I find I need my defrosters in some weather conditions, AC or no, especially with long plowing runs. Keep in mind that AC does not cycle on below 30-40F as the pressure in the system is too low to trip the LP cutout switch, so you really get no AC when it is reasonably cold...whether the light is on or not. I'm very glad I have them, and I got the side defrosters too. Not sure those were needed as much, but the rear sure is. The sides help a little at least, but not as critical. I do notice the fogging in the sides first though, which is my clue to hit the button (or hit it again). But then with -20F temps this winter I may be in a different boat than other posters here (though not the guy from Warren, MN...). My $0.02

BTW there is a defogger relay which may have the timer in it instead of the switch. It wasn't noted in the schematic that there even was a timer, though there obviously is somewhere. Not sure, but I agree it would be nice to have it at least run a longer cycle, as it is too short.

Well the Canadian Grand L series machines come with the rear defog one the three windows as standard equipment. You can't buy one up here without it on the unit. I've never seen a rear defog that didn't have an internal timer on it. In the automotive word they all got it.
I also know the AC compressor isn't used during cold temps but if I went out in mine well below freezing and in extremely cold temps without that AC button pushed I would see out any of the glass in five minutes. It must make a difference to the way it recycles the air in the cab :confused3:

 

[Jts771]

I agree with Paul. When plowing in single digits temps if I turn off the ac windows fog up in a matter of minutes

 

[Kubotafan]

I find I need my defrosters in some weather conditions, AC or no, especially with long plowing runs. Keep in mind that AC does not cycle on below 30-40F as the pressure in the system is too low to trip the LP cutout switch, so you really get no AC when it is reasonably cold...whether the light is on or not. I'm very glad I have them, and I got the side defrosters too. Not sure those were needed as much, but the rear sure is. The sides help a little at least, but not as critical. I do notice the fogging in the sides first though, which is my clue to hit the button (or hit it again). But then with -20F temps this winter I may be in a different boat than other posters here (though not the guy from Warren, MN...). My $0.02

BTW there is a defogger relay which may have the timer in it instead of the switch. It wasn't noted in the schematic that there even was a timer, though there obviously is somewhere. Not sure, but I agree it would be nice to have it at least run a longer cycle, as it is too short.

I am in the tractor for six to eight hours after a storm doing residential driveways, and sometimes the snow has to be blown into the wind, and that is when the glass gets covered with a lot of snow. The fogging may not be as bad in warmer weather, but when it is quite cold out the defrost is a must for me. I have a B3030HSDC and the defrost stays on until it is shut off. (Just thinking to myself, I should check to see if it has the same profile as the L3540.....that switch may work in the L3540.....) I asked the service manager at my dealer and he said the timer is built into the switch on the L3540. I thought maybe it could be unplugged but that isn't an option.

Even with the defrost the cab would fog up without running the A/C. I keep the heat up too when it is windy so the snow will quickly melt off the glass. No coat is needed in the cab, and in cold weather there is lots of heat to keep you sweating.