Rear Window Defrosters In Convertibles

69-Tin Indian · Guru

Rear Window Defrosters In Convertibles

03cts sport · Uber Guru

Defrost or defog? I always understood a defroster to be a heating element, while a defogger was a blower? I'm curious to see the responses, as I can only imagine a defroster in a glass rear rag window...

NOS · Poncho Master!

rear window defrosters come as part of the convertible package and have pretty much been standard since early 90's . I t was an option on the 71-75 GM convertibles particularily the Cadillacs. They simply plug into a wiring harness which accomodates the movement of the window.
Even cars sold in tthe southern states have rear defrosters.

Dale @ NOS

03cts sport · Uber Guru

Glass windows I assume?...

seventy2plus2 · Canadian Poncho Superstar!

My 70 2+2 convertible has rear window defog. There's a blower behind the rear seat (basically the same as on the rear package shelf) and it's outlet is parallel with the top of the rear seat facing up to the rear window. Controlled by 2 speed rocker switch on the dash. One of the 2 lines from the rocker switch to the fan motor uses resistive wire, so that's the low speed. High speed uses non-resistive wire.

NOS · Poncho Master!

03cts sport wrote:

Glass windows I assume?...

you got it

cdnpont · Canadian Poncho Superstar!

Lets see a picture of it Clint if you could. I've never seen one.

67Poncho · Uber Guru

cdnpont wrote:

Lets see a picture of it Clint if you could. I've never seen one.

The 2+2 Rag I have posted for sale has it as well. First time I saw it also. Just a little grille that is out of the rear of the back seat attaching frame.. Don't have a pic, though!

gtodrive · Guru

seventy2plus2 wrote:

My 70 2+2 convertible has rear window defog. There's a blower behind the rear seat (basically the same as on the rear package shelf) and it's outlet is parallel with the top of the rear seat facing up to the rear window. Controlled by 2 speed rocker switch on the dash. One of the 2 lines from the rocker switch to the fan motor uses resistive wire, so that's the low speed. High speed uses non-resistive wire.

My 69 has the defog also with a glass window. I question its effectiveness though. I have always found warm air to be more effective in defogging rather than cold moist air from the trunk! But, they must work...seen them on a lot of cars!

-- Edited by gtodrive on Tuesday 13th of April 2010 12:18:52 PM

eeluddy · Uber Guru

My old 74 Corvette convertible had a rear defog blower, plastic window. My 90 Allante has a glass rear with defrost wires embedded.

69-Tin Indian · Guru

My '69 Grande Parisienne hardtop has one and of course it's mounted in the rear parcel shelf. As said previously, I know the ragtops did have them in some of the cars but I was just curious how they were mounted on the rear of the back seat or affixed to the steel behind the seat or what.
A picture really would be ideal if anyone can snap one. As far as defrost or defog goes, I'll remember next time to be "correct" in my part description.

seventy2plus2 · Canadian Poncho Superstar!

here's a photo of the rear defogger in my 70 2+2 rag. It's a sunny day here, and the defog grille is just above the shadow line. You can also see the rear tail light monitor that screws to the top of the rear seat - a rare option for a convertible. I got it from a fully loaded (but extremely rusty) 70 2+2 rag near Peterborough ON.

4SPEED427 · A Poncho Legend!

I knew they existed but I'm not sure I've ever seen one in person.

Cool.....

69-Tin Indian · Guru

Hey Clint, thanks very much for posting a pic of how the unit is mounted on the rear part of the back seat. Good straight forward picture. I only asked because I have a unit out of a '69 Grande that I was thinking about installing in my '69 Parisienne ragtop as I restore it.