Convertible Hardtop window defroster
Thread Starter
Heel & Toe
Joined: Oct 2010
Posts: 17
Likes: 0
Convertible Hardtop window defroster
I have a 93 convertible that did not come with a hardtop. I have purchased a hardtop and would like to get the rear window defroster hooked up and working. Has anyone done this before or have any ideas?
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
There is a positive 12v cable for the defogger that is located near the passenger side shoulder belt tower. You will have to look under the carpeting in that area to find it. The wire will be orange and will have a single black connector.
You will have to make a ground wire using 14ga wire. One end will attach to the ground lead on the hardtop rear window. The other end needs to be attached to a good ground point; the driver's side shoulder harness tower will work fine. Just use a metal screw and a wire terminal. It would probably work better to just cut the terminal off the ground side wire and just get a male and female connector for 14ga wire. Because that ground wire will remain in the car, use a ring terminal to attach it to the car.
In the Owner's Manual where it discusses the HVAC system, there should be a pic of the HVAC control head that shows what button operates the hardtop window defogger. From what I remember with my '92 vert, the standard control unit and the Climate Control unit show different buttons for the defogger.
For a test, turn the ignition to ON and push the button that indicates operating the defogger. Use a voltmeter to test for 12v at the orange wire. You may need to add a fuse and possibly a relay to get the orange wire to show 12v.
You will have to make a ground wire using 14ga wire. One end will attach to the ground lead on the hardtop rear window. The other end needs to be attached to a good ground point; the driver's side shoulder harness tower will work fine. Just use a metal screw and a wire terminal. It would probably work better to just cut the terminal off the ground side wire and just get a male and female connector for 14ga wire. Because that ground wire will remain in the car, use a ring terminal to attach it to the car.
In the Owner's Manual where it discusses the HVAC system, there should be a pic of the HVAC control head that shows what button operates the hardtop window defogger. From what I remember with my '92 vert, the standard control unit and the Climate Control unit show different buttons for the defogger.
For a test, turn the ignition to ON and push the button that indicates operating the defogger. Use a voltmeter to test for 12v at the orange wire. You may need to add a fuse and possibly a relay to get the orange wire to show 12v.
Instructor
Joined: Oct 2012
Posts: 104
Likes: 6
From: Long Beach MS
I have a 93 Convertible and when I replaced the Rag Top, I bought the one with the glass window retrofit with defroster. Thinking that the convertibles probably had the same wiring as the Coupes, a mechanic apparently confirmed this. It was an easy hook-up, and my outside mirror defroster button works the rear window defroster. I do remember that it took him less than 30-minutes to do the job. I wish I could be more specific, but it was close to 20-years ago.
Thread Starter
Heel & Toe
Joined: Oct 2010
Posts: 17
Likes: 0
Thank you!
I have a 93 Convertible and when I replaced the Rag Top, I bought the one with the glass window retrofit with defroster. Thinking that the convertibles probably had the same wiring as the Coupes, a mechanic apparently confirmed this. It was an easy hook-up, and my outside mirror defroster button works the rear window defroster. I do remember that it took him less than 30-minutes to do the job. I wish I could be more specific, but it was close to 20-years ago.
