Exploding rear window
#811
Senior Member
#812
Here's a few pics of Shadetree's rear slider window defroster bypass mod done on my 2014 XLT Screw Boost. With this mod, your truck's heated mirrors will heat and your in-dash rear defroster lamp will light, but your rear slider window defroster will not come on with the dash switch or with the remote start until you perchance to revert the mod somewhere down the road.
HEADS UP (edit) My method shown here is an overcomplicated way of doing this mod, but it demonstrates good wiring techniques that you could use elsewhere so I'm leaving it up. Shadetree has since documented a simpler method which doesn't involve modifying the harness. However, I think the cleanest overall way to do the mod would be to make a jumper of two small female spade connectors and a short piece of wire, then jump across the pins inside the OEM plug. Maybe the first person to attempt this technique will add a few pix to the topic...?
And here goes! I promise not to get as carried away with the documentation as I did with my DRL topic.
First up: You need to fold the passenger rear seatback down. This is a pic of the seatback release lever. The seatback is already folded down in this pic. Follow the red arrow to the little lever that has to be pulled upward to release the seatback. First you fold up the lower part of the seat, then you reach behind to unlock the back. Some folks use a box-end wrench to get leverage; I used my fingers. Next you release the lower part and finally fold the whole assembly down flat to the floor. It's really quite easy.
Attachment 485569
Here's a pic of the defroster connector, already disconnected for testing purposes. The slider crosses through the upper left quarter of the picture.
Attachment 485570
This is a pic of the lower half of the connector, removed from the back wall of the cab and prepped for Shadetree's mod in the way I like to do my wiring. I use a thermal wire stripper to peel back enough insulation to solder onto the bare wire. This technique won't damage the conductors in the slightest. You could also use a lighter to melt the insulation and a gentle touch with a pair of wire cutters to peel it away, but be careful or you'll nick the conductors .
Attachment 485571
Here's the 18ga jumper wire ready to be soldered. I used a little more wire than I needed so that I could simply cut and e-tape it off later if necessary, as opposed to digging back into the harness and desoldering old work.
Attachment 485572
And here's the finished work, with both lines individually e-taped and then taped together, and the connector remounted to the back cab wall. I simply wedged the other half of the connector behind the wire harness where it won't rattle loose. Done and done.
Attachment 485573
HEADS UP (edit) My method shown here is an overcomplicated way of doing this mod, but it demonstrates good wiring techniques that you could use elsewhere so I'm leaving it up. Shadetree has since documented a simpler method which doesn't involve modifying the harness. However, I think the cleanest overall way to do the mod would be to make a jumper of two small female spade connectors and a short piece of wire, then jump across the pins inside the OEM plug. Maybe the first person to attempt this technique will add a few pix to the topic...?
And here goes! I promise not to get as carried away with the documentation as I did with my DRL topic.
First up: You need to fold the passenger rear seatback down. This is a pic of the seatback release lever. The seatback is already folded down in this pic. Follow the red arrow to the little lever that has to be pulled upward to release the seatback. First you fold up the lower part of the seat, then you reach behind to unlock the back. Some folks use a box-end wrench to get leverage; I used my fingers. Next you release the lower part and finally fold the whole assembly down flat to the floor. It's really quite easy.
Attachment 485569
Here's a pic of the defroster connector, already disconnected for testing purposes. The slider crosses through the upper left quarter of the picture.
Attachment 485570
This is a pic of the lower half of the connector, removed from the back wall of the cab and prepped for Shadetree's mod in the way I like to do my wiring. I use a thermal wire stripper to peel back enough insulation to solder onto the bare wire. This technique won't damage the conductors in the slightest. You could also use a lighter to melt the insulation and a gentle touch with a pair of wire cutters to peel it away, but be careful or you'll nick the conductors .
Attachment 485571
Here's the 18ga jumper wire ready to be soldered. I used a little more wire than I needed so that I could simply cut and e-tape it off later if necessary, as opposed to digging back into the harness and desoldering old work.
Attachment 485572
And here's the finished work, with both lines individually e-taped and then taped together, and the connector remounted to the back cab wall. I simply wedged the other half of the connector behind the wire harness where it won't rattle loose. Done and done.
Attachment 485573
#813
I couldn't read through all the threads. I stopped around the 200 mark lol. Just wanted to add that this happened to me yesterday on my 2014 F-150 Lariat. Drivers side rear window. Scared the crap out of me. Waiting on my 2018 being built. Hope they fixed this issue.
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digitaltrucker (04-06-2018)
#815
Senior Member
Thanks man that was an easy way to get the heated mirror and the light working again, it’s not overcomplicated at all. The hard part was to get to the connection it probably was the first time the back seat were folded and had a hard time folding the 1/3 part where the connection is. I wish I had think of it myself a simple loop to get the electric signal go back to the dash! I still think it sucks to have to bypass the defrost on a truck to feel safe about the rear window exploding but no trucks are perfect.
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Blue2016XL (05-12-2018)
#817
Senior Member
#818
Senior Member
No, all it does is disable the heating grid on the rear window. The grid actually still receives power and becomes charged so the feedback wire gets the signal it "expects" and everything else works as normal. The grid simply has no path to ground so there is no current flow. The only difference is, under normal operation the feedback wire sees about 5 volts. With the ground pulled it sees full system voltage, 14-ish. It doesn't matter, it's a reference signal only.
#819
Senior Member
So your mirrors defrost but your back window does not break.
OK Enough already. I should be able to come up with a design so the window does not break but still defrosts.
For those of you that have the resistors left over from your LED marker/turn signal lights, can you get a close up so I can read the value?
The little gold ones.
OK Enough already. I should be able to come up with a design so the window does not break but still defrosts.
For those of you that have the resistors left over from your LED marker/turn signal lights, can you get a close up so I can read the value?
The little gold ones.
#820
Senior Member
What are you thinking, reduce power by 1/4 or something?