Howdy all: A possible project I am considering for my 122s is to add defroster wires to the rear window...there are some kits available for that, but I would like to know if anyone has had that experience of doing that on their 122s. Any advice or warning appreciated!

Thanks!

-DS

For what it's worth,,, a couple of weeks ago I was at a car show and there was this guy with a 1967 Saab 96 with a V4 engine,, well while I was looking at his car the owner showed me how he adapted a rear defrost blower out of a BMW convertible and he told me that it works OK. He told me that he got it on Ebay for TEN bucks......

About 4 years ago I bought at an old business that was closing a NOS Interdynamics
Hot Air Rear Defroster&Defogger ,, for 8 bucks,, they do not make them anymore,, but it works GREAT,, a bit noisy, works fast, do not need to run it for more than 2 to 3 minutes,, it even has a nice vintage look and looks OK on the rear shelf....

I have tried both in North East winters a hot air blowing one, (admittedly cheap JC Whitney) just defrosted little circles where it blew.
The heated wire one, (more expensive from a supplier of these sort of things) worked well but after one winter the wires pretty much dissolved leaving it usless the second year.
...And as has been said both drew A LOT of current.

Cardog, you mentioned that the heater wires dissolved the next year...made me wonder if you included a timed circuit to auto-shut off the current to the wires? Just wondering what is the current output limit to protect the wires, even with the auto shut off circuit.

-DS

David;

Two types powered by electricity are available...both use lots of power (~10A) so should not be installed unless you have upgraded the charging system to 60A...the heated resistance element type which is adhered to glass...I'd recommend against it from the standpoint of not creating localized thermal differences in the glass...I recommend the blown warm air type...I've installed these (with a relay!) with success.

Cheers

Thanks, Ron.

I have already had the conversion to 60 amp in the car, but I did consider adding a rear window fan. It would be really cool. Any pictures to help give me an idea?

And I also did consider the risk of cracking the glass not designed for on-contact heating of the wires. But is there any proof for the 122 cars? I was just hoping that there would be someone (or someone who knows someone) out there who has actually had the experience of customizing the rear glass with the wires...and getting advice from that experience whether good or bad!

And as for buying defroster-ready glass, $$$ is quite boggling, but thanks for the link.

-DS

I have the rear fan in my Amazon. It was was installed when I bought the car. It has three speeds and uses a switch similar to the wipers.


--
1959 Volvo Amazon 121, 1998 Volvo V70R AWD

Nifty, thanks for sharing the pix, Lukeball. I imagine it works, drawing heated air from the front to the back, right?

-DS

It has been my experience over the years that simply by opening the rear quarter windows a crack, the inside of the rear window clears immediately.
FF

Hello,

I hope you realize that the price listed at the VP website for the rear windshield with defroster built in, is in Swedish Kronas and not US dollars.

When converted to US dollars the rear windshield is around $250.00, which I believe is a VERY reasonable price.

Have you priced a replacement rear windshield on a modern car, SUV or truck?

I remember a local news story about a some vandals shooting out mostly rear windshields of parked vehicles with s BB or pellet gun in a residential neighborhood and hearing the reporters claiming that some of the broken glass cost over $1000.00 apiece!!
--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502

Eric, you are right...it is a VERY reasonable price. I guess it was my knee-jerk reaction when I glanced at the numbers without thinking that it was not in USA dollars. Am I seeing right, that price includes freight?!

Thanks,

-DS

Hello,

I am pretty sure the price does not include shipping.

We have purchased and installed one of the windshields over a year ago in a 1967 122.

The windshield does not include any wiring, switches or relays.

And it is important for the longevity of the heating grid that a proper timing relay that automatically shuts off the power to the defroster after about 10 minutes.

We opted for a relay/switch kit from Frost Fighter.
--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502

If the adhered to glass type element is to be avoided because of "localized thermal differences" (not to mention trying to clean the glass surface with the wire in the way) why would glass with embedded conductors be any better?

My GUESS:
The resistance wire is probably pretty soft and ductile and is planned to operate at
low current and fairly low temperature. When turned on it will be at the temperature of
the glass to which it is bonded and it will warm up relatively slowly, bringing the glass with it.
Most kinds of glass conduct heat fairly fast and have a fairly LOW coefficient of thermal
expansion. (You can water-quench quartz glass from 1000°F and not break it.)
Also the core of tempered glass is under pretty great tension because of the heat treatment.
Warming it does NOT make it expand, it just reduces the tension.
--
George Downs Bartlesville, Oklahoma

Thanks, George for sharing what you think in relation to thermal-diffusion principle. Something for me to think more on.

-DS

Heated rear window glass is available from VP-Autoparts.
http://www.websitefolder.net/VPAUTOPARTS/art-2.asp?id=2991