Question regarding the Windsheld defrost

[Tdizz11]

The early JK dash only had center defrost vent. The updated JK dash has outward vents, but don’t know if they are functional. I believe they are.

Please tell me that I don’t have to do this to a a $42,000 Wrangler so that I can see out the windshield

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[Lou_JLU]

Discovered this yesterday on the JL I picked up this week. Has anyone driven the JL in winter yet? The JK windshield vents were stupid and the wipers always froze. Why do we have vents that do nothing?

I picked up my JL at the end of February and had a chance to drive it in the end of winter snowstorms which aren't really that cold. I recall the windshield icing up a bit and the wipers... well the wipers froze up. After coming from vehicles which had an area on the windshield with wiper heaters I had gotten used to having clear wipers in all but the very worst storms.

I had forgotten this until Maguro's post on the windshield defroster performance. Ideally, to remedy the defroster I would like to get under the front dash area and get measurements of the defrost exit area and have one of the guys at work 3D print a plenum to fit in that area a redistribute hot air. That is not a this year project.
However, there is time to install a good wiper heater system on the front windshield before the bad weather comes in. I've been looking at a couple websites to accomplish this. User spec'd 12V heaters can be obtain at: https://www.oemheaters.com/category/982/12v-and-24v-silicone-rubber-heaters. Some research required for the proper watts per square inch for this item and an adequate controller. Complete systems for user install can be found at: https://www.frostfighter.com/catalog.htm. I was thinking of using the controllers available at this website for the 12V silicone rubber heaters on the OEMHeater site. Like I said I've just started researching....

I was going to perform the install and post it as a DIY project complete but there are those who can probably get this done faster than I could and do it well. I have a tendency to over analyze and take too much time.

 

[maguro]

I picked up my JL at the end of February and had a chance to drive it in the end of winter snowstorms which aren't really that cold. I recall the windshield icing up a bit and the wipers... well the wipers froze up. After coming from vehicles which had an area on the windshield with wiper heaters I had gotten used to having clear wipers in all but the very worst storms.

Thanks for confirming that. We're about to get around 4" of snow and temperatures down to 15F this week so at least I know what to expect.

Jeep says that the JL has undergone nearly 4 million miles of testing. I wonder how many of those were in Canada. It's not uncommon for it to drop down to -40F up here. It's not uncommon for us to receive a foot of snow overnight. The cold weather package is a nice touch but what's the use of a warm backside and hands if I can't see out the windshield?!

I can almost forgive Jeep if the windshield defrost consisted of a small vent in the central area of the dash. But having the vents extend to the ends as a cosmetic feature just adds insult to injury.

Either way, I'll report back as we start to get hammered with snow and freezing temperatures. Who knows? Maybe the airflow gets diverted to the ends if the temperatures drop beyond a certain level?

 

[Tdizz11]

Thanks for confirming that. We're about to get around 4" of snow and temperatures down to 15F this week so at least I know what to expect.

Jeep says that the JL has undergone nearly 4 million miles of testing. I wonder how many of those were in Canada. It's not uncommon for it to drop down to -40F up here. It's not uncommon for us to receive a foot of snow overnight. The cold weather package is a nice touch but what's the use of a warm backside and hands if I can't see out the windshield?!

I can almost forgive Jeep if the windshield defrost consisted of a small vent in the central area of the dash. But having the vents extend to the ends as a cosmetic feature just adds insult to injury.

Either way, I'll report back as we start to get hammered with snow and freezing temperatures. Who knows? Maybe the airflow gets diverted to the ends if the temperatures drop beyond a certain level?

Notice all of the stock Jeep pictures are in the desert. I guess they didn't want pictures on their website of a Jeep with solid ice on the wipers. I guess I'll be putting my winter wipers on....or buying new ones because I'm sure the JK wipers won't fit!

 

[Brad41]

Funny I’m seeing this thread as I just used defrost last night for the first time and noticed the middle of the windshield clearing very quickly, and the left and right side remaining foggy. Sure enough, no air blowing there, but only in the middle.

 

[maguro]

Funny I’m seeing this thread as I just used defrost last night for the first time and noticed the middle of the windshield clearing very quickly, and the left and right side remaining foggy. Sure enough, no air blowing there, but only in the middle.

In a few months time, I have a feeling we'll be seeing more defrost threads than steering threads.

 

[NCIC105]

Must be cosmetic, my 8/18 build has the same concern

 

[Grousemont]

Posted this question in General JL but it didn't get far so I thought I'd post my query here.

It's pretty much winter up here in the Canadian Rockies and I had to use the windshield defrost for the first time this past week.

When I use the windshield defrost, I get warm air coming out of the green area but no airflow at all from the red area. (Of course this picture omits the passenger side of the dashboard but it's the same thing on that side.)

So the end result is that the center portion of the windshield becomes free of snow and ice but the edges remain frozen. What's up with that?

Is it just mine? Can someone hit the windshield defrost on their center dash (top left corner) and tell me if they get any airflow from the vents towards the ends?

I just Tv’d the vent. It seems the dash vents blowing horizontal is where the constriction begins. There is a continued void from center defrost vents and the left and right defrost vents but air will flow path of least resistance thus out the middle. In the pic attached you’re looking at the dash vents and the defrost vent to the left of center. So one could simply block the center defrost and air would flow to the sides.

 

[NCIC105]

I just Tv’d the vent. It seems the dash vents blowing horizontal is where the constriction begins. There is a continued void from center defrost vents and the left and right defrost vents but air will flow path of least resistance thus out the middle. In the pic attached you’re looking at the dash vents and the defrost vent to the left of center. So one could simply block the center defrost and air would flow to the sides.

Thanks. Good explanation.

 

[Grousemont]

I took another look at the defrost exit vent and from the far left to the far right it appears to be one continuous trough with the defrost vent exit in the middle portion about 2 - 3 inches down. Seems like the only thing missing is an air plenum placed at that exit area to direct the flow into the sides of the trough and across the entire exit area and onto the windshield.

Yup. I TV’d it and it is a continuous trough but with constrictions (see my later post) that push the air up the middle.

 

[maguro]

We received 20cm of fresh snow last night so it was a good time to take the JLUR for a test drive. As expected, this is the result. The center was relatively clear but the edges and the area above the wipers were iced over, despite running the windshield defrost for around 15 minutes.

As Grousemont mentioned above, I was able to block the center vent (using a book I had lying around) which forced the air out of the vents on the edges. This eventually led to a clear windshield.

However, it was only around 30F today. If it happened to be -30F, I'm guessing that the center would quickly frost over as I obstructed the center vent do divert airflow to the edges.

How could FCA not notice this?!

 

[AlamedaJeep]

Just had my first experience with snow and cold weather with my JL and I can add further confirmation to the above information about the defroster performance. All the air comes out of the center vent, clearing the center of the windshield and leaving the sides foggy.

Since I had read this thread, I knew to block the center vent to force the air out the side vents and clear the sides of the windshield. I had to run the defroster for several minutes before it was clear enough to drive. It’s a waste of time and energy to solve a stupid problem.

 

[Shenanigans]

Mine is having a different defrost issue. With the defrost set to about 70-78, the windshield defrost vent on the drivers side is smoking hot and the passenger side is freezing cold. It gets so hot on the drivers side when set at 70 degrees that it is uncomfortable to drive it. Then when I turn the temp down, there is no change. I just got my heat gun back and I’ll play with the temps and get an actual reading with a video in he next few days.

 

[JeepCares]

Just had my first experience with snow and cold weather with my JL and I can add further confirmation to the above information about the defroster performance. All the air comes out of the center vent, clearing the center of the windshield and leaving the sides foggy.

Since I had read this thread, I knew to block the center vent to force the air out the side vents and clear the sides of the windshield. I had to run the defroster for several minutes before it was clear enough to drive. It’s a waste of time and energy to solve a stupid problem.

Mine is having a different defrost issue. With the defrost set to about 70-78, the windshield defrost vent on the drivers side is smoking hot and the passenger side is freezing cold. It gets so hot on the drivers side when set at 70 degrees that it is uncomfortable to drive it. Then when I turn the temp down, there is no change. I just got my heat gun back and I’ll play with the temps and get an actual reading with a video in he next few days.

Hi AlamedaJeep and JeepX3,
We understand how concerning this must be now that winter is on the way. Please send us a private message if you choose to have your dealers look into this so we can offer our assistance while your Jeeps are being serviced.
Lydia
Jeep Social Care Specialist

 

[jamielong]

Hi AlamedaJeep and JeepX3,
We understand how concerning this must be now that winter is on the way. Please send us a private message if you choose to have your dealers look into this so we can offer our assistance while your Jeeps are being serviced.
Lydia
Jeep Social Care Specialist

Lydia

Can you confirm how the design is supposed to work ,Mine has air coming from only the center vent and this has been a huge issue already with defrosting the windshield in humid or foggy conditions .I am in the northeast and we will be getting 30 degree weather starting this week . I had my Jeep in for service as the EGR valve was defective and they " looked at it " compared it to other Jeeps on the lot and determined it works as designed and nothing was wrong . I have a hard time believing that the design is for air to only come from the center vent .

Advice ?

Jamie

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