Rear Window Defroster - 1970

[Alexandra #40022]

Hi all,

I was looking over someones vette vues book last night and saw a photo of the rear window defroster vent in the rear of a coupe (on the drivers side rear panel behind the seat)...........and Ive got this vent on my car. I was wondering what it was for!!

but the problem is, I don't have the chrome button (defroster switch) on the drivers side lower console side panel -(sorry for my descriptions!)

Either of these panels could have been replaced.......how do I tell which one was! or how do I tell whether my car does actually have the rear window defroster or not? (possible check out wiring or something?).

and if it does check out that I do have this option but the button side panel trim piece has been replaced....does anyone know where I can get one of these chrome buttons /switches?

Thanks for your time and help.

Cheers,
Alex

[Joe L.]

Re: Rear Window Defroster - 1970

Alexandra-----

If you have the rear deck mounted grille, then I'd say it's a virtual certainty that the car was originally equipped with the rear window defogger. Unless a major section of the car was replaced, it's hard to imagine that the grille would have been otherwise added.

The system consists of the console-mounted switch, the wiring harness from the switch to the left rear isde of the car, the blower assembly, ducting, and the deck-mounted grille (configuration of some components differs between coupe and convertible). The blower motor assembly, which is the primary functional component of the system is mounted in the left, rear of the luggage compartment, in the area between the inner fender well and the rear door jamb. It is partially or completely covered by the rear quarter trim panels.

Just how much of the system remains you will have to determine by inspection. It's very possible that the console was replaced at some point and the switch hole not cut into the new console. The switch, itself, originally GM #3942676 and later replaced by GM #3998399, are both long-since GM-discontinued. As far as I know, it is not reproduced. However, it may be possible to use other available "generic" switches as a replacement since this is a quite simple switch. The remaining components, except for some ducting and seals available from Dr. Rebuild, are not available from GM or in reproduction. The used marketplace is the only source I know of for them.

[Warren F.]

Re: Rear Window Defroster - 1970

Alexandra:

If you attend Corvettes @ Carlisle event, there are several vendors with this side piece, containing the defogger switch, used.

If you e-mail me, I can give you some numbers to call. Also call the major corvette vendors, most of their catalogues also deal in good used parts.

[Alexandra #40022]

Rear Window Defroster - 1970

Hi,

Thanks for your replies. I really appreciate your help.

Joe: Your description was great. Thankyou. Armed with your description and the 70 AIM I tried having a look to see if my vette was still (or if it was ever) equipped with this rear window defroster option.

Unfortunately Im even more confused than ever! I had a 'feel' behind the vent of the rear trim panel and I can feel a duct coming from this but going to 'nothing' ..it just ends without serving a purpose. I can't find the blower motor either.

Maybe Im not looking in the right spot.......or maybe my worst suspicions of the car are true - maybe the previous owner has put 'bits and pieces' throughout the car.......that are not original. He has already changed the interior from vinyl to leather...and the door trims.....and the console trim - (which Im already upset about!!).

Im a member of the NCRS in Australia...but currently only being a new chapter,I don't think there are too many people familiar with c3's who could help me out. Although, I know they would be willing to help out!

If Im supposed to have the rear window defroster...I want to restore it that way...I want to fix these sorts of things.

I will attempt to have another look again today...and let you know how I go.

Thanks again for your help! I love learning more about these awesome cars!

Alex

[Joe L.]

Re: Rear Window Defroster - 1970

Alex-----

If there is a grille and ducting present, then I'd say that the car was once equipped with the rear window defogger. The blower is located, as I mentioned, on the driver's side rear compartment area between the inner wheel well and the rear of the door jamp. It's not something that's "subtle" and easily missed if you look in this area. The most likely scenario is that the blower has been removed. If you wish to restore it, you'll need to look for used components.

Have you checked to see if the car still has its tank sticker on the driver's side, upper surface of the fuel tank? If it does and you drop the tank to remove and/or inspect it, you may be able to confirm if it originally had the C-50 rear window defogger.