Fixing wiper issue with snow

[dyeager535]

Nope, no visor. Pretty much stock exterior.

You running stock length wipers, or longer? Did the snow actually pile up on the windshield or hood? What year is your truck?

Since I'm running longer wipers, and I have them set so they are as close to flat as possible at rest, perhaps that contributes to the issue. But on the '73-80's, I wonder if enough heat comes through the cowl that it warms the windshield somewhat?

 

[Blue85]

Are you sure the airflow is switching to the defrost vents as much as it should? Could be a vacuum leak to one of those vacuum motors or there could be foreign objects in the vents. I have pulled a lot of pens and stuff out of defrost vents on some square nose trucks.

 

[black dawg]

Nope, no visor. Pretty much stock exterior.

You running stock length wipers, or longer? Did the snow actually pile up on the windshield or hood? What year is your truck?

Since I'm running longer wipers, and I have them set so they are as close to flat as possible at rest, perhaps that contributes to the issue. But on the '73-80's, I wonder if enough heat comes through the cowl that it warms the windshield somewhat?

91 burb. The wipers are slightly longer than stock, dont remember the length. Wipers go down to parrallel with bottom of windshield during use.

some snow built up on cowl, none on hood, basically had snow (an inch thick?) every where that the wipers didnt clear.

Burb had been in use from about 5am till about 7pm when the really heavy snow started. So maybe stuff was heatsoked somewhat? About 34ish outside temp. Never looked at the speedometer, probably 45-55 mph. all on interstate.

 

[dyeager535]

I don't have AC, nor dash pad. I can tell they work lol.

Look at where the vents dump on the drivers side. They are nowhere near the end of the wiper blade. Even on full bore, engine fully warmed, in ~20* weather, the glass will never get hot enough to melt snow that starts to pile up fast.

 

[Blue85]

Make a custom duct.

 

[dyeager535]

Burb had been in use from about 5am till about 7pm when the really heavy snow started. So maybe stuff was heatsoked somewhat? About 34ish outside temp. Never looked at the speedometer, probably 45-55 mph. all on interstate.

Maybe heatsoak is part of the issue, but I had the same problem cruising on the freeway one time as well, so the truck was nice and "hot" at that time. This last time I figured letting it warm up would take care of it, but did not.

Anyone notice their windshield getting HOT in cold weather with the heater on high? Wondering if part of the problem is just a crummy aftermarket heater core. I know in sub-freezing temps my windshield won't even be warm, but no idea if that is normal or not. Coming out of the vents it's pretty warm, just not the windshield.

 

[black dawg]

my windshield did not feel warm, but didnt have a way to actually check temp. And like I said, I get very little out of the defrost vents anyway.

 

[dyeager535]

I could certainly make something even temporary to see if I could make it work better in that area, unfortunately I don't have the opportunity to test it out often.

 

[Jester1]

Up here we have that problem often. The solution for us is to make sure you brush away the snow from the hood, glass and roof areas after you start the rig to warm up. You can always tell the noobs in our area because they don't. As you drive the snow will blow back from the hood and accumulate there faster, then when you step on the brakes it slides off the roof and catches there also usually blocking all view and too heavy for the wipers to move. That area has always been a concern even on non chevy rigs. I have even heard of people getting pulled over by the cops because of the impeded view. Once the snow is on that area the defroster can't warm the glass faster than the snow is cooling it in that area. If the snow is gone the glass can come up to temp and has a better chance of melting it on contact.

I don't want you to think this is a smart a$$ answer to your problem it is just part of our morning ritual living here.

I am also running the longer wipers at one point I tried 20" and they overlapped the swipe better, but they ran over the edge of the rubber at the top and put a strain on the motor. Now I run 18" and still have that bit of gap in the center. Clearing the snow as I said above keeps it from the glass then the defrosted seems to keep up when driving during light the medium snowfall. I also at times employ the turn it on at full speed and fling it tactic before it slides down to the center.

 

[dyeager535]

No offense taken. Glad I'm not imagining this issue. I certainly did not clean the truck off good the last time, but it was only maybe 2-3 inches of snow, and wasn't moving fast enough to blow anything into the windshield, or fall down into the wipers...it was just snowing heavily. But the vehicle was also cool when I started moving.

Are you saying then that IF you start off with a snow free hood/roof/windshield, you don't have problems at all, or will it pile up eventually if snowing hard enough? You make sure the heater is up to temp before even trying to head out?

In the one instance, even the wipers blades were starting to ice up, and I'm pretty sure the truck started "clean" on that drive. Been a few years, like I said, don't deal with it here that often, so it's always new in a sense.

 

[Blue85]

Is there anything under the dash pad in that area? This discussion has me wanting to find a 3rd little defroster grill and cut the dash pad there to fit it. Then rig up custom ductwork to it.

I do notice that snow wants to build up there, but generally when I'm driving around I get enough hot air that it slides down. Super cold weather and heavy snowfall is the worst-case, of course.

 

[Jester1]

No offense taken. Glad I'm not imagining this issue. I certainly did not clean the truck off good the last time, but it was only maybe 2-3 inches of snow, and wasn't moving fast enough to blow anything into the windshield, or fall down into the wipers...it was just snowing heavily. But the vehicle was also cool when I started moving.

Are you saying then that IF you start off with a snow free hood/roof/windshield, you don't have problems at all, or will it pile up eventually if snowing hard enough? You make sure the heater is up to temp before even trying to head out?

In the one instance, even the wipers blades were starting to ice up, and I'm pretty sure the truck started "clean" on that drive. Been a few years, like I said, don't deal with it here that often, so it's always new in a sense.

It will pile up a bit depending on 1. How cold it is outside and 2. How much the snow is falling. So think of it this way, snow is actually a good insulator it will help keep everything under it a constant temp. If it is up against you windshield it is constant. Air blowing on it is trying to heat something that is blanketed to a given temp is now harder. Now when you melt the snow the water underneath become another layer between the glass and snow and will not allow the glass to come to any kind of warm temp. I don't know if I am explaining this correctly but I hope you get the idea. All of this also depends on outside temp and how wet/sticky the snow is.

Point being metal and glass have a better chance of warming up and melting away new if the cold blanket is removed. I am talking about 0-40 * once you are below 0 and moving everything iced up with a moving vehicle induced wind chill. Hope this helps. I have made it through some nasty stuff here (-35 to -45 with wind) and have found moving it off before you start reduces a lot of problems for the rest of your day.

 

[dyeager535]

I think it's the sheet metal of the dash unfortunately.

This why I think at least as an experiment, the thin film 12V handwarmers might be a decent test to see if it can be solved by heat alone.

No idea how heat will affect the laminate in the glass though, I assume at some temp it will start to break down. I'd guess that sitting in the sun probably brings it up to roughly the same temp.

 

[89yimmiJ]

I bought one of these to try out. Gets warm fast.

http://t.harborfreight.com/12v-auto-heater-defroster-with-light-60525.html

 

[dyeager535]

I've got one of those for another project, completely forgot I could try it lol. Of course, I've got the thin film handwarmers handy as well, but they aren't plug and play like the heater.

Now of course, if we only got enough snow to test it out soon...

 

[campfire]

Even on full bore, engine fully warmed, in ~20* weather, the glass will never get hot enough to melt snow that starts to pile up fast.

As Jester1 said, this white wet stuff is daily routine for many of us. Failure to clean the truck well enough can cause problems, but I would think that any vehicle unable to melt off a medium snowfall (say, 1/2" per hour) when warmed up and cleaned is probably not defrosting as well as intended. I consider my K10's defrost to be rather wimpy (needs more airflow), but it takes a fairly heavy snowfall to ice the windshield wipers up. My DD is wimpier yet (scraping frost on the inside, anybody? ). It will ice up much more readily than a good modern vehicle. But multiple times this week I have driven through heavy snowfall and had few problems melting it off (once it got warm).

Anyone notice their windshield getting HOT in cold weather with the heater on high? Wondering if part of the problem is just a crummy aftermarket heater core. I know in sub-freezing temps my windshield won't even be warm, but no idea if that is normal or not. Coming out of the vents it's pretty warm, just not the windshield.

IMO, your defroster (even if it's crummy like mine) should be able to keep a windshield warm to the touch below freezing (depending on how much outside air is flowing over it). But as said before, it's really hard to heat a windshield when it is cold and blanketed in cold melting water. Melting takes a huge amount of energy...

 

[campfire]

Now of course, if we only got enough snow to test it out soon...

Come up to da U.P! We've got plenty to share!

 

[Jester1]

I'll test it for ya. 6-8 " here in the valley. 16-24" in the mountains tonight. Updates to trucks in the spring not that I got much done this summer anyways.

 

[campfire]

Are you saying then that IF you start off with a snow free hood/roof/windshield, you don't have problems at all, or will it pile up eventually if snowing hard enough? You make sure the heater is up to temp before even trying to head out?

In the one instance, even the wipers blades were starting to ice up, and I'm pretty sure the truck started "clean" on that drive. Been a few years, like I said, don't deal with it here that often, so it's always new in a sense.

If it's snowing badly out, waiting till the heater (and windshield!) is up to temp will definitely help with the snow removal. But if it's snowing hard enough it will freeze over. It's a matter of how quickly, and it varies quite a bit between vehicles. And what flavor of washer fluid you are using.

 

[dyeager535]

Now that it's winter and I've already experienced this issue again (plus my wipers now park in the wrong spot, I suspect because of the piles of snow from last year) I'm dredging this back up.

Dad brought up something I had not considered...anyone with a stock dashpad, can you tell me if those are louvered to direct air to the middle of the windshield? I have no dashpad, if the pads are a help in directing the heated air, might be part of my issue. For some reason though, I want to think that the plastic insert in the dashpad for the defrost vents is just square holes, they don't really direct the air?

Jester, you ever get around to trying the hand warmers? Either that or using something to direct the airflow to that area is all I can come up with as a potential fix at this point. And I'd hate for the handwarmers to delaminate the windshield there.