Adding rear window defogger/defroster question

[Tim7139]

Looking at the diagram in this thread https://www.ramforum.com/threads/wiring-diagram-heated-mirrors.134474/ it looks like there is a separate box connected to the Power Distribution Center for the rear window defrost.<edit: there is not, I read that wrong>

Does anyone have pics and location of that and any other modules/relays I need to acquire and/or points I can tie into wiring?<edit: my truck had everything>

 

[Tim7139]

Components get referred to as: electric back light, backlite-electric heated, heated glass element, defroster, defogger.
Relay is K10, marked as EBL. Already present in my 2020.
Fuse is F36 30 amp, marked as Rear Defroster(if equipped). Already present in my 2020.

Looks like just wiring and connectors to sort out, but not having much luck there. Powered back glass connector connects though circuit C15 to the PDC connector pin 87 for fuse 36. Not sure if C15 can be tied into the existing body harness at some point, and if so where that point would be.

"the A/C heater module energizes the EBL relay in the Power Distribution Center (PDC) and fused battery current is directed to the rear window defogger grid lines and the heated outside rear view mirrors, when equipped."
"- Confirm the EBL feed wire is connected to the heating grid positive terminal and that there is continuity between the PDC and the heating grid."
"- Confirm the EBL ground wire is connected to the heating grid negative terminal and that there is continuity to ground."

 

[Tim7139]

Everything was present and live! I popped the trim off the pillars and the connectors were taped in place. Pulled them out, connected a multimeter and got current when the defrost switch is activated.

Now I just have to decide between replacing the rear window, or trying a Frost Fighter stick kit and a tab bonding kit. So far I've only seen one install video and it did not have the attractive finished look their brochure mentions.

 

[Skyjockey]

Ever get it working?? I have manual slider but would like to get something on the back for snow?? Even aftermarket

 

[Mleads310]

I'm curious as well

 

[Tim7139]

Waiting to hear back from the Frost Fighter Canadian rep, but I have no doubt that a window with the defroster will work.

 

[Ram35Fan]

I think it's what you're saying, but maybe you can confirm for me....if you get a rear window swapped out, based on what you see is it as simple as plug-and-play? That's the situation I'm in, I broke my rear window and accidentally installed one with the defrost grid lines. Thanks in advance!

 

[Tim7139]

I think it's what you're saying, but maybe you can confirm for me....if you get a rear window swapped out, based on what you see is it as simple as plug-and-play? That's the situation I'm in, I broke my rear window and accidentally installed one with the defrost grid lines. Thanks in advance!

Yes. The connectors were in place, and got voltage when I hit the switch.

The panel is easy to pop off with just one screw, so no reason not to check (other than wanting to stay inside for this cold snap...)

 

[Ram35Fan]

Yes. The connectors were in place, and got voltage when I hit the switch.

The panel is easy to pop off with just one screw, so no reason not to check (other than wanting to stay inside for this cold snap...)

Thanks for the reply! I'll make sure to let you know how it goes; it's supposed to be +5c up North here on Tuesday and being out in the bush for a hunt that day should be a perfect recipe for great testing conditions...moisture in the cab or early morning frost!

I'm curious to see what the cable/connector situation looks like on the rear window as it's been a while since I was behind there (dripping headliner, a story for later). Cheers.

 

[Tim7139]

Thanks for the reply! I'll make sure to let you know how it goes; it's supposed to be +5c up North here on Tuesday and being out in the bush for a hunt that day should be a perfect recipe for great testing conditions...moisture in the cab or early morning frost!

I'm curious to see what the cable/connector situation looks like on the rear window as it's been a while since I was behind there (dripping headliner, a story for later). Cheers.

Should be a metal button on the lower corner of the window on each side to connect to. I pulled both trim pieces off the side pillar and found a wire with a plastic clip that was not connected that had it's end taped up to the wiring harness.

 

[Ram35Fan]

It worked! I don't know if this is the right place or not but I'll post some pictures and whatnot here (hopefully it helps someone out).

I didn't originally have a heated rear window, but after accidentally breaking it 3 years ago I had it replaced (at a cost of over $600 CAD!!!) with a window that had the defrosting grid lines. Being in a Northern climate, certain times of the year make the rear window darn near impossible to defrost unless you're on a long road trip with the heat in the cab on COOK. Getting into the truck when wet (hunting trips and work) also meant having to deal with poor visibility out the back, so this was long overdue.

I wish I knew it was so easy because I've wanted to do this since I bought the truck, but could never find the right info. I thought I was going to have to scour scrapyards for wiring harnesses, relays, etc. . . So THANKS TIM!!!

This project took all of 30 minutes, and that was with my 3 year-old daughter helping me, so one could reasonably expect to get this done in 15-20 minutes.

View media item 30157For what it's worth, this was all done on a 2015 Ram 3500 SLT Mega Cab with the Cummins.

View media item 30158I removed the inside panels on both sides. The black lower panel pulls out first, then the upper panel comes off next.

View media item 30159To remove the upper beige panel, you have to remove the two protective caps/plugs (labelled #1). This is easily done by prying from the top and with something plastic to avoid gouging the plastic panel. Then pry the cap off of the seatbelt head, and remove this bolt.

View media item 30160Be careful when pulling out the 2 screws, otherwise they could fall down into the abyss where you'll need to do a lot more work removing the rest of the panel to find the screw (or get lucky like I did when using an extendable magnet tool).

View media item 30164This is what it looks like with the panels off.

View media item 30165This is the extra push connector you'll need to free-up, the drivers side had 2 pieces of tape to remove until it would reach the window port it connects to, while the passenger side had 3.

View media item 30166A closer look at the connector all taped up

View media item 30167We're FREE!

View media item 30168I didn't know how everything plugged in/was connected, but when complete the push connector is only open on one side which makes for a good and finished look.

View media item 30169I used the extra push clip that was already attached to the push connector cable and plugged it into the steel hole it's pointing at.

View media item 30170This is the button connector which will slide into your push connector on either side

View media item 30172When everything was plugged in, I tested it by blowing on the rear window and activating the defroster. IT WORKS!!!!!

Hopefully this helps someone out!

 

[doublet1201]

Good Evening Everyone and Merry Christmas. I have a 2015 Ram 2500 ST 6.7 Turbo Diesel. I have recently added an aftermarket fixed rear window with a defrost system installed on it. My truck did not come with a rear window defroster. I have a snow plow prep package that I use, but no rear defroster. That conversation is for another time. LoL!! I spent many hours searching the internet for how to tie in the rear defroster to the heated mirror system. That only makes sense right??

Here is what I have discovered. You cannot order/find the correct wiring harness coming from the window. Ram does not offer it. the wiring harness coming off the window ties into some type of other module. So, I traced my heated mirrors back to relay K7 in the power distribution box under the hood. The plugs are color coded inside the power distribution box. It is located on the grey plug. When I disconnected the grey plug I found it literally powered nothing. So, my thinking is that K10 powers F36 rear window defrost (if equipped). I bought the proper connector to install my wire into the wiring harness running into the power distribution box. K10 relay is powered by a red with a pink stripe wire on one side two empty slots, and then a blue wire on another relay. I tested my installed wire with a test light and it received power when I powered the heated mirrors, and cut power when I turned off the heated mirror button.

Now to the window attachment problem. I used this company frostfighter.com they specialize in replacement parts for rear defoggers. You would think I could get a replacement attachment from them? Not so much!! I ended up purchasing universal connector kit and installing it on the defroster grid below the OEM attachment points. The kit simply had me sand the top layer of the grid to expose the silver metal of the system. Then I applied some silver adhesive that was conductive to pass the current from the wiring harness into the defroster grid. I wired it up and everything is good to go. I now have a rear defroster on a timer that I did not have to cut into the dash to install another button somewhere.

Lastly, I am just your average DIY truck enthusiast. I installed strobe lights for snow plowing, trailer brakes, do my own filter changes, and plug & play programming. Please keep in mind this was on a 2015 4th generation truck, not a 2019 or newer 5th generation. The wiring between generations specifically most likely will be different as well as trim levels in the 4th generation. This solution worked for me. Sorry for not taking pictures, but I normally don't think about taking pictures when I am troubleshooting wires and such. Any questions please feel free to reach out, if you feel the need to bash my post please don't reach out. I intend only to help others needing a rear defroster.

Thank you and I wish everyone Happy Holidays!!

Tony

Rear Window Link: https://www.ebay.com/itm/Fits-2009-2019-Dodge-Ram-Pickup-Rear-Window-Back-Glass-Heated-Stationary-2-Glue/201677136952?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

Defroster Repair Kit Link: https://frostfighter.com/catalog/rear-window-defroster-repair-solutions/defroster-repair-bundle.htm

 

[Kinger1234]

It worked! I don't know if this is the right place or not but I'll post some pictures and whatnot here (hopefully it helps someone out).

I didn't originally have a heated rear window, but after accidentally breaking it 3 years ago I had it replaced (at a cost of over $600 CAD!!!) with a window that had the defrosting grid lines. Being in a Northern climate, certain times of the year make the rear window darn near impossible to defrost unless you're on a long road trip with the heat in the cab on COOK. Getting into the truck when wet (hunting trips and work) also meant having to deal with poor visibility out the back, so this was long overdue.

I wish I knew it was so easy because I've wanted to do this since I bought the truck, but could never find the right info. I thought I was going to have to scour scrapyards for wiring harnesses, relays, etc. . . So THANKS TIM!!!

This project took all of 30 minutes, and that was with my 3 year-old daughter helping me, so one could reasonably expect to get this done in 15-20 minutes.

View media item 30157For what it's worth, this was all done on a 2015 Ram 3500 SLT Mega Cab with the Cummins.

View media item 30158I removed the inside panels on both sides. The black lower panel pulls out first, then the upper panel comes off next.

View media item 30159To remove the upper beige panel, you have to remove the two protective caps/plugs (labelled #1). This is easily done by prying from the top and with something plastic to avoid gouging the plastic panel. Then pry the cap off of the seatbelt head, and remove this bolt.

View media item 30160Be careful when pulling out the 2 screws, otherwise they could fall down into the abyss where you'll need to do a lot more work removing the rest of the panel to find the screw (or get lucky like I did when using an extendable magnet tool).

View media item 30164This is what it looks like with the panels off.

View media item 30165This is the extra push connector you'll need to free-up, the drivers side had 2 pieces of tape to remove until it would reach the window port it connects to, while the passenger side had 3.

View media item 30166A closer look at the connector all taped up

View media item 30167We're FREE!

View media item 30168I didn't know how everything plugged in/was connected, but when complete the push connector is only open on one side which makes for a good and finished look.

View media item 30169I used the extra push clip that was already attached to the push connector cable and plugged it into the steel hole it's pointing at.

View media item 30170This is the button connector which will slide into your push connector on either side

View media item 30172When everything was plugged in, I tested it by blowing on the rear window and activating the defroster. IT WORKS!!!!!

Hopefully this helps someone out!

Hey man what about the center sliding window is there a wire for that window too

 

[Ram35Fan]

Hey man what about the center sliding window is there a wire for that window too

It gets the power from the 2 plugs I've shown, some type of sliding tab on a powered rail I believe.