1978 - 1996 Big Bronco  
Sponsored by:
Sponsored by:

How to wire in a rear defroster

Thread Tools
 
Search this Thread
 
  #1  
Old 11-04-2015, 10:48 AM
AbandonedBronco's Avatar
AbandonedBronco
AbandonedBronco is online now
Moderator
Thread Starter
Join Date: Dec 2007
Location: Boise, Idaho
Posts: 7,936
Received 79 Likes on 72 Posts
How to wire in a rear defroster

Hello all,

I'm replacing the rear glass in my '81 with defroster glass. It didn't come with it originally, so I don't know what wiring may or may not be present. There obviously isn't a switch up front.

Does anyone have any info on how to wire one in? Can I just use any defroster switch, such as this one?



Or does it need to be the stock one?

Any tips, guidance, advice anyone can give?

Thanks!
 
  #2  
Old 11-04-2015, 02:13 PM
1985 Bronco's Avatar
1985 Bronco
1985 Bronco is offline
Laughing Gas
Join Date: Nov 2013
Location: Minnesota
Posts: 1,200
Likes: 0
Received 3 Likes on 3 Posts


I have a factory switch if you want to buy one, I pulled it from the gray 86 in my build thread. No idea how to wire it in though. PM me if interested.
 
  #3  
Old 11-22-2015, 09:44 AM
AbandonedBronco's Avatar
AbandonedBronco
AbandonedBronco is online now
Moderator
Thread Starter
Join Date: Dec 2007
Location: Boise, Idaho
Posts: 7,936
Received 79 Likes on 72 Posts
So, I took a trip to visit my brother last weekend (about 150 miles away) and we parked our Broncos side by side. He has a rear defroster and I do not. I was able to see what all he had and what I was missing.

By the looks of it, the wiring plug to plug into the defroster switch is present on my Bronco. So, all I need to do is attach the stock defroster switch to the dash and plug it in.

However, he has a much larger brick of wires going into the tailgate. I only have 2 wires, whereas he has all the ones for the defroster. So, I will need to see how far the wires up front go before stopping. My guess is that it goes to the fuse box and then stops.

If that's the case, I'll need to run a wire from wherever the power ends to the back of the bronco and solder it onto the window. The window has two prongs on it, so from what I can tell, one goes to a ground, and the other to the power source. Shouldn't be overly complicated.
 
  #4  
Old 11-22-2015, 09:52 AM
gatorfor88's Avatar
gatorfor88
gatorfor88 is offline
Postmaster
Join Date: Jan 2013
Location: Panama City
Posts: 3,512
Likes: 0
Received 3 Likes on 3 Posts
Probably can buy a factory pigtail from a source. Dont know who but they are most likely out there.
 
  #5  
Old 09-13-2018, 04:53 AM
vroma's Avatar
vroma
vroma is offline
Senior User
Join Date: Sep 2016
Posts: 165
Received 0 Likes on 0 Posts
Originally Posted by AbandonedBronco
So, I took a trip to visit my brother last weekend (about 150 miles away) and we parked our Broncos side by side. He has a rear defroster and I do not. I was able to see what all he had and what I was missing.

By the looks of it, the wiring plug to plug into the defroster switch is present on my Bronco. So, all I need to do is attach the stock defroster switch to the dash and plug it in.

However, he has a much larger brick of wires going into the tailgate. I only have 2 wires, whereas he has all the ones for the defroster. So, I will need to see how far the wires up front go before stopping. My guess is that it goes to the fuse box and then stops.

If that's the case, I'll need to run a wire from wherever the power ends to the back of the bronco and solder it onto the window. The window has two prongs on it, so from what I can tell, one goes to a ground, and the other to the power source. Shouldn't be overly complicated.
did you have any luck fixing this?
 
  #6  
Old 09-13-2018, 06:54 AM
AbandonedBronco's Avatar
AbandonedBronco
AbandonedBronco is online now
Moderator
Thread Starter
Join Date: Dec 2007
Location: Boise, Idaho
Posts: 7,936
Received 79 Likes on 72 Posts
Well... Yes and no.
The vehicle was totaled, so I never got to finish it. But, I got another Bronco and it has defrost.
So, I didn't end up adding defrost myself.
 
  #7  
Old 09-13-2018, 08:37 AM
vroma's Avatar
vroma
vroma is offline
Senior User
Join Date: Sep 2016
Posts: 165
Received 0 Likes on 0 Posts
Originally Posted by AbandonedBronco
Well... Yes and no.
The vehicle was totaled, so I never got to finish it. But, I got another Bronco and it has defrost.
So, I didn't end up adding defrost myself.
Damn, I assume whoever was involved survived safe and healthy from the accident. That said, sorry to hear about that tragedy (the loss of a Bronco).

I started a thread elsewhere on this forum about this topic (before I saw your thread above) and I have yet to find a solution or receive a response that helps.
In parts, I have the switch and tailgate parts but nothing connecting them together. I think I’ve seen a multi-wire harness that runs along the length of the truck along the left frame rail from the cab to the taillights, and I think one of these wires powers the defroster but without the dash switch connection, I’m at a loss.

Is there any chance you could take photos of your defroster cable that connects to the dashboard switch?
 
  #8  
Old 09-14-2018, 03:13 PM
AbandonedBronco's Avatar
AbandonedBronco
AbandonedBronco is online now
Moderator
Thread Starter
Join Date: Dec 2007
Location: Boise, Idaho
Posts: 7,936
Received 79 Likes on 72 Posts
Thanks for asking. No one was seriously injured. I had a month or two of physical therapy to loosen my neck muscles that spasmed, but that was about it. The Bronco did its job.
Going to miss it though!!

I'll try to remember to get a picture of the defroster cable where it attaches to the switch tonight.
 
  #9  
Old 09-14-2018, 05:45 PM
vroma's Avatar
vroma
vroma is offline
Senior User
Join Date: Sep 2016
Posts: 165
Received 0 Likes on 0 Posts
Originally Posted by AbandonedBronco
Thanks for asking. No one was seriously injured. I had a month or two of physical therapy to loosen my neck muscles that spasmed, but that was about it. The Bronco did its job.
Going to miss it though!!

I'll try to remember to get a picture of the defroster cable where it attaches to the switch tonight.
I can just image... back then crash zones meant the whole vehicle.

Thanks for the photos.
 
  #10  
Old 09-15-2018, 09:03 AM
AbandonedBronco's Avatar
AbandonedBronco
AbandonedBronco is online now
Moderator
Thread Starter
Join Date: Dec 2007
Location: Boise, Idaho
Posts: 7,936
Received 79 Likes on 72 Posts
In this case, it was the rear corner. The car was lower, so they went underneath. The frame was okay, just so much damage to so many different panels of the vehicle that it would have cost a fortune to get it back in fighting shape.

Here's the defroster plug for ya



 
  #11  
Old 09-17-2018, 08:51 AM
vroma's Avatar
vroma
vroma is offline
Senior User
Join Date: Sep 2016
Posts: 165
Received 0 Likes on 0 Posts
Originally Posted by AbandonedBronco
In this case, it was the rear corner. The car was lower, so they went underneath. The frame was okay, just so much damage to so many different panels of the vehicle that it would have cost a fortune to get it back in fighting shape.

Here's the defroster plug for ya



Thanks, AbandonedBronco.
Well, I’m certainly missing that wire harness!
Fixing this should be fun.

 
  #12  
Old 09-17-2018, 09:13 AM
AbandonedBronco's Avatar
AbandonedBronco
AbandonedBronco is online now
Moderator
Thread Starter
Join Date: Dec 2007
Location: Boise, Idaho
Posts: 7,936
Received 79 Likes on 72 Posts
Thinking back to when I was looking into tackling this project, the defroster was the only thing that seems like it's not included in the default wiring harness. Most everything else, even if the truck didn't come equipped with it, has the wiring available. Not sure why the defroster doesn't.
 
  #13  
Old 09-17-2018, 09:35 AM
vroma's Avatar
vroma
vroma is offline
Senior User
Join Date: Sep 2016
Posts: 165
Received 0 Likes on 0 Posts
Originally Posted by AbandonedBronco
Thinking back to when I was looking into tackling this project, the defroster was the only thing that seems like it's not included in the default wiring harness. Most everything else, even if the truck didn't come equipped with it, has the wiring available. Not sure why the defroster doesn't.
So I should be able to plug in a harness?
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
superduty4x4
1999 - 2003 7.3L Power Stroke Diesel
15
09-06-2021 10:50 PM
ATC Crazy
2017+ Super Duty
34
05-13-2019 09:49 AM
thehawk75
Excursion - King of SUVs
1
07-08-2012 08:17 PM
fcarruth
1978 - 1996 Big Bronco
12
11-01-2005 08:59 AM
jvcajw
1978 - 1996 Big Bronco
4
03-29-2003 11:50 PM



Quick Reply: How to wire in a rear defroster



All times are GMT -5. The time now is 01:32 PM.