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Coated windshield impacting door openers and EZpass

johnmodels

Member
Feb 2, 2013
166
69
SoCal
Thanks for the research guys!!! I mounted my gate transponder to the plastic holding the rear view mirror to the windshield and for the first time it worked!!!
 

aaron.s

Member
May 31, 2012
999
36
Guys

I can also confirm with my NY/NJ E-ZPass that if you hold it up by the stem (mount) for the rear view mirror, it works like a charm!

Aaron
 
Jul 2, 2012
62
1
Mounting the new smaller EzPass to the black plastic mount above the rear view mirror worked for me on the Nj Turnpike all four times I tried it and the Commodore Barry Bridge as well.

ezpass.jpg
 

Mark Z

Active Member
Mar 12, 2013
1,842
1,300
North Orange County
Tommy's and Eelton's mirror mount area works perfectly. The large FasTrak can be placed directly on the mirror mount as shown. Move the left Velcro so both strips are in contact with the mirror mount. I used an extra Velcro and left the original strip in place.

BFUsoWgCMAAcm2L.jpg


Mounting the large FasTrak in the recessed area of the rear hatch is a great alternative for those who don't want to mount it at the mirror. Saves the hassle of obtaining a license plate mounted model and removing the nose cone for invisibility. Since the license plate model costs more, The Toll Roads and 91 Express Lanes like the use of the standard pass. Here is the LINK.
 

Mark Z

Active Member
Mar 12, 2013
1,842
1,300
North Orange County
Disregard rear hatch mounting

I received a reply to a question about the rear hatch transponder location. Here is the reply:

"Thank you for contacting The Toll Roads.

In accordance with the California Vehicle Code, it is not permitted to place the transponder in the rear window.

The internal transponder may be placed on the lower left-hand side or right-hand side of your windshield or behind the rear view mirror where it will not obstruct your sight while driving.

At times, we have found that the polarized windshields have prevented the internal transponder from reading at all times. Therefore, it may be necessary to replace your internal transponder with an external one.

This recommendation is presented in situations when the internal transponder fails to read while properly mounted and generates a significant number of tolls which are paid by the license plate number instead of the transponder number.

The external transponders mount directly to the front license plate brackets and are secured with tamper-resistant screws. A special tool is provided in order to remove/affix the external transponder.

Internal or external transponders do not cost more than the other. If you would like to request an external one, please feel free to respond to this email and we will process your request."


My thoughts: I did some additional research and the Bay Area web pages had this posted on their site:

"*Amendment to SEC.77, Section 26708 of the Vehicle Code, permitting:
An electronic communication device affixed to the center uppermost portion of the interior of a windshield within an area that is not greater than 5 inches square, if the device provides either of the following:
(A) The capability for enforcement facilities of the Department of the California Highway Patrol to communicate with a vehicle equipped with the device.
(B) The capability for electronic toll and traffic management on public or private roads or facilities.


SEC. 77, Section 26708 of the Vehicle Code is amended to read:
Signs, stickers, or other materials which are displayed in a 7-inch square in the lower corner of the windshield farthest removed from the driver, signs, stickers, or other materials which are displayed in a 7-inch square in the lower corner of the rear window farthest removed from the driver, or signs, stickers, or other materials which are displayed in a 5-inch square in the lower corner of the windshield nearest the driver."

Now it sounds as if the California Highway Patrol may scan the vehicle for a working pass while on patrol. If that is true, then the mirror mount location would be best.

Since I cannot edit my posts due to my status, my previous suggestions will remain in the thread.
 

kcveins

delivery 2/7/13
Jul 24, 2012
399
554
Chicagoland
Thanks for the tips - I will try this. The new iPass is much smaller than the older old and looks like the picture of the EZ pass posted 4 posts above.
In Illinois, if you want to get the external transponder for the iPass, you have to pay an extra $10 - but they warn you that if there is even a little crack in it and water or snow gets into it, it will stop working and we have to replace it at our cost. There were also 2 people in the iPass facility on Tuesday saying that their external transponders had been stolen, so it is relatively easy to unscrew from the license plate.
 

Mark Z

Active Member
Mar 12, 2013
1,842
1,300
North Orange County
The only remaining challenge with the mirror mount location OR the transponder located behind the nose cone is the California Vehicle Code where it requests that the device be visible. Only motorcyclists have the ability to "hide" the transponder from view. Here is the link:

V C Section 23302 Refusal to Pay Tolls

"...the device shall be located in or on the vehicle in a location so as to be visible for the purpose of enforcement at all times when the vehicle is located on the vehicular crossing or toll highway."

The large FasTrak transponder is partially visible from the drivers side, but it disappears on the passenger side.

It will be interesting how an officer handles a partially visible, perfectly working transponder mounted above the rear view mirror in the preferred mounting location.

vehicleMounting.png
 

DSK

Member
Mar 28, 2013
11
0
Atlanta
just to add my 2 cents (to this dead horse?):

I have two AVI/RFID type stickers, Peach Pass (Georgia tolls) and one for my work garage.

It took some experimentation, but as a couple of other people already noted (and I thought I was going to be the first), I have slide each of them under the black plastic housing of the rear view mirror. I have NOT removed the backing for the sticky side. I think they will stay, or I may use a small piece of double stick tape. I have tested each, they both work great now. I can post or send pics if anyone needs them. The peach pass sticker is long and thin, that one is almost completely hidden under the plastic housing (right side - north/south orientation . The work garage AVI is credit card sized and the main part is under the housing (and pushed up under the fabric above) and about 1/3 is exposed (left-side of mirror in east-west orientation). But it all works!

It would have been very helpful if Tesla had given us easier access to under the nose or the front part of the roof (the 7" wide or so strip that runs between the windshield and the pano roof).

 

Cheerose

Member
Mar 4, 2013
212
18
Las Vegas, NV
Why not use the front bumper mount that the tolls (like Peach Pass) offers? Is it security (since the tag is now exposed to the public) or the fact that it just doesn't "look" right?
If you could post a picture of the Peach Pass, that would be great. (If you already have one on the Atlanta FB site, I can look for it there as well)
 

DSK

Member
Mar 28, 2013
11
0
Atlanta
@Cheerose

not exactly what you were asking for, but here is this got Peach Pass to work (in case any of you are still having issues) | Forums | Tesla Motors

you can also go to the peach pass website to see the rfid strip. To answer your question, I could have used the front bumper mount, but only as a last resort. I did not have the front bumper pre drilled to have the mount. And, you are right, I would not like the way it would look, but, if you have to then you have to. Lastly, I did not try it, but my understanding is that it might not work if you tried the rfid strip as low as the bumper. Having said that, I would have tried it INSIDE the black plastic shield first. Fortunately, I did not have to try that.
 

MichaelS

Supporting Member
Aug 8, 2012
319
51
Hayward CA
I just mounted my FASTRAK license plate mount transponder under the nose cone. And it works great.

I first mounted it on the front lower grill below the nose cone. It worked once, then failed the second time. I realized there is a big steel support member right behind the nose cone that was probably blocking the RF signal.

I mounted the transponder with Velcro on the front of the steel member right below the rounded bulge. The nose cone seems to fit perfectly back into its location. The nose cone probably holds the transponder in place.

I would guess that a regular windshield transponder would also work in that position as long as its mounted sticking out a bit.
 

flybob08

Member
Jan 10, 2013
90
0
Sugar Land, TX
Glad to hear that. I just did the same thing with Velcro earlier today and was holding my breath. Nose cone came off pretty easily and the pictures on other threads were right on. I used a small plastic pry bar to get it popped off.
 

flybob08

Member
Jan 10, 2013
90
0
Sugar Land, TX
Placing the EZ toll tag license plate bar (black) behind the nose cone on the metal bumper just below the upper ridge on the bumper works like a champ. Gates jump open early. Works better than the window toll tag did on my old BMW Icer - feels like a new pair of Keds

IMG_0235.jpg
IMG_0237.jpg
 
Last edited:

MikeK

R#129, TSLA shareholder
Jun 29, 2012
1,133
1
San Francisco Bay Area
I had success with the FasTrak transponder in that location behind the mirror on two attempts, but not on two subsequent attempts. I do have two transponders, so I'm going to try the other on the off chance that the battery crapped out. The nose cone location is not ideal because of situations where you are not required to pay a toll (e.g. the HOT lanes).
 

gg_got_a_tesla

Model S: VIN 65513, Model 3: VIN 1913
Jan 29, 2010
6,533
769
Redwood Shores, CA
I had success with the FasTrak transponder in that location behind the mirror on two attempts, but not on two subsequent attempts. I do have two transponders, so I'm going to try the other on the off chance that the battery crapped out. The nose cone location is not ideal because of situations where you are not required to pay a toll (e.g. the HOT lanes).

It's inconsistent for sure. Reviewed my FasTrak transactions online and found that, between 02/16/13 (when I started using the transponder-behind-the-mirror) through today, out of 43 attempts, only on 12 occasions did it NOT work (the plates were ID-ed instead). Still not bad at all.
 

W8MM

R1.5 #325 + Mdl S #01380
Jan 5, 2007
202
1
Cincinnati, USA
I think the windshield is just not coated there, due to other antennas housed under the plastic.

Bingo -- we have a winner! I'm an RF engineer and agree completely.

After I looked at our car closely, the fact that the metallic coating is absent only in the area covered by the plastic mirror area cover is important. The only place for RF transponder signals to pass through the windshield is in this area. The plastic cover passes the signals without too much attenuation and the message traffic can snake around what metallic contents are contained under the cover. The coated windshield areas completely short out any RF trying to pass. The uncoated area allows for signal passage obstructed only by the contents hidden by the plastic cover.

Radar detectors are very unlikely to work behind the plastic cover without serious consideration of the placement of objects hidden by the cover. Toll transponders use VHF or UHF frequencies that can more easily tolerate minor obstructions due to their wavelength. Radar signals can be completely blocked by elements too small to seriously affect toll transponders.
 

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