does anyone have a picture of a factory 70 rear defogger grill? I have 2 different grills not sure witch is correct for a 70. thanks

I don't have a picture handy but the 70 defogger grille is metal and rectangular shaped with rounded corners. The slits on one side will be straight and the other side will be angled a little. Hope this helps.

Both of the original ones on my 70's are plastic and look like this:

http://www.chevelles.com/forums/showthread.php?p=1474410#post1474410

The vents pictured above are not correct for a 70 Chevelle. The correct grill is metal as mentioned before.

Go look inside your trunk at the underside of the metal package tray shelf. Measure the size of the opening where the defroster vent goes....that is the size of the bottom of the slim rear defroster vent that just slips inside the opening from the interior on top of your package tray. The large rectangular ones would not even come close to fitting in my Atlanta built '70 SS. It's my understanding (I'll let the 71-72 guys chime in here) is that the larger rectangular ones with the vents straight on one side and angled on the other were changed for the 1971-1972 model year. If you need a picture from the interior or from the inside the trunk, I would be happy to get one or 2 snapped and posted in this thread for reference.

Nah, the steel one as mentioned above fits perfectly in the hole on package tray, and is the factory set-up . The vent you have pictured look as though they were removed from a Cadillac. The vent was changed to plastic for the 71 72 chevelle and other GM A bodies . I do have this exact set-up installed in my 70, along with the correct date coded blower motor. The opening on the package tray should be a circle and a sqaure surrounded by three holes which allows the welded studs on the back of metal grill to attach to package tray. The convertible set-up has a grill that looks something like what you have but its different. There is a black plastic trim piece that is installed under the metal grill that has the circle and square opening thats in the package tray (there is also a piece of insulation that goes under the black trim that fits between the package tray and the plastic trim under the grill). I can send you a picture of the correct set-up , but I cannot post a picture in the forum (can someone else do that for me).

That looks like a '69 Chevelle grille. I think our '69s have the holes for the defroster that bolts to the bottom of the parcel shelf and also the slot for this type of defogger which bolts to the trunk divider below the parcel shelf.

One thing we all have learned is that it's possible there can be more than one right answer when it comes to saying what is correct for Chevelles. It's certainly possible that different plants used different parts, some plants did things differently, part shortages, substitutions and part changes were possible throughout the model year. At the same time, here are some pictures from my restored 1970 SS using all the original parts. If you have a different original setup, might be helpful to post up your pictures too.

Here is the top (from the interior) of the rear defroster vent that used the original slim style that is just like the black one pictured in the other thread for 1970.

http://i23.photobucket.com/albums/b400/bendoregon/checklist004.jpg

Here is a shot of the trunk that shows the blower motor attached to the ductwork leading to bottom of the vent:

http://i23.photobucket.com/albums/b400/bendoregon/checklist007.jpg

And finally, here is the bottom of the vent from the trunk. Note how it just fits into the slot of the metal package tray and how the bottom of the package tray was precut from the factory that it fits into:

http://i23.photobucket.com/albums/b400/bendoregon/checklist011.jpg

This car also has the stereo rear speakers on each side of the defroster. All stock, all restored original.

thanks alot guys :)

I will stick to what i said and believe that you do not have the original unit in your car. That looks like a Cadillac or big GM car. I have never scene that unit factory installed in a chevelle. Maybe this is some dealer kit or something, but I'm sure that unit is incorrect to be factory installed.

70SS, that's fine too. You may want to check your buildsheet if you have one to see if your car originally came with a rear window defroster from the factory (I've got mine and it's right there on the build sheet in block 107 listed C50 RR WDO DEFOGG). If yours is original and documented, then there may have been more than one way they were done. It's also possible that your larger version may have been added later as the precut/stamped metal rear package shelf will only accomodate the slim version for my Atlanta built January 1970....the bigger vent grill you mention simply would not fit or slide into the slot provided. Every documented one from the factory that I have seen is exactly like the one pictured for 1970. You may also want to check to see if your rear package shelf has been cut to allow for the bigger vent or if your dash was modified/cut to allow for the rear defroster switch also. Good discussion! Reminds me of the metal versus plastic inner fenders discussion.

Yay, whatever, Car came factory installed and every chevelle I've ever scene had the same cut out in the package tray. I doubt if being a Alanta car made any difference. I had probably 100 of the metal set-ups that I have sold over the last 30 years and all were the same. You must be right though, Alanta cars must be special.

I put a factory rear defogger in my '68 Firebird when it was about a year old. People might think that it came with the car. You just never know unless you have owned the car since new. GM did a lot of wierd stuff.

SS4Real, I have seen the one you have there in a 69 Chevelle and a 70 Pontiac GTO. My 70 is a Arlington car built in May. The package tray only has the cut out for the cover that I described and that 70SS is talking about. I agree that you may have something there, about there could have been something going on with GM. We've seen that before. Maybe since your car is a Jan. 70 that is was an item that was left from the 69 model year run, and was installed in your 70. Just speculation, but possible.

Ernie,

You may be correct in your reasoning if you have seen the slim vent set-up in both a '69 Chevelle and a '70 GTO. It was very common for GM to carry over and use parts from one model year to the next, if possible. Many of these parts were also common to different GM makes to save costs and for standardization. That's exactly why I mentioned you must measure the size of the opening in the metal package shelf to see which vent fits and the build date of your car. Interesting to note, there is a defroster dated 2-72 on ebay right now. Note the size and shape of the square top defroster vent grill and you will notice that it would certainly not fit in the slot that mine is factory precut for and shown in the bottom photograph from the inside of the trunk that I've posted. That leads me to believe that the vent cutout in the package tray was bigger for the 1971-1972 model years and possibly was changed during the 1970 model year if somebody can offer up some picture and buildsheet documentation that supports that view. It's all about the discovery.

1972 dated vent:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=008&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=180194980190&rd=1

1971 Vent removed from a 1971 Monte Carlo

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=260195178920&ssPageName=STRK:MEWA:IT&ih=016:

Both units are 71 - 72 units in the ebay auctions (all plastic), but the footprint is the same as the 70 unit. The opening in the package tray was the same for all three years, not long and rectangular. The correct 70 unit has a metal blower housing and a grill that is metal and is pictured in the ebay auction below. The switch in that auction is a 69 unit. Like I said the unit you have is incorrect for a chevelle and I find it hard to believe that GM would punch out package trays special to only the Altanta cars. Believe me I have been parting out and selling parts for these cars for nearly 32 years and never scene your set-up in a 70 chevelle. You seem like someone who is'nt going to listen otherwise, so I guess you should be happy with what you have. I bet if you look at the opening on your package tray you will see that it was cut in there way after it left the factory. I have scene many of these set-ups in Caddillacs from the 60's and 70's that mounted on the back of the seat back. Infact one of the mounting ears on your vent seems kind of ripped up or modified on the end, that surely is not factory.









http://cgi.ebay.com/ebaymotors/1968-1969-SS-Camaro-Chevelle-Rear-Defrost-Rear-Defog_W0QQcmdZViewItemQQcategoryZ46094QQihZ011QQit emZ320197300367QQrdZ1QQsspagenameZWDVW

For what it is worth...

The "pilot" LS6 is a factory defogger car built in Baltimore in Dec '69...it has the metal rectangular defogger...I've also owned an Atlanta LS6 which was built in Dec '69 (late) and it too had the metal rectangular grate...both have original dated blower motors and were factory defogger cars...I've also owned 2 other '70's with defoggers, 1 SS L34 and a malibu which had the metal rectangular defoggers...They were also factory call outs on the buildsheets..

It is my understanding the metal rectangular rear defogger is the correct RPO unit....The over the counter or dealer installed accessoried defoggers are the narrow units, which I believe also include some duct work in the trunk..The rectangular units blow directly on the glass and the grating serves to direct airflow..

SS4real...I'd be very skeptical that your car has its' RPO unit..as I've owned an Atlanta car built roughly the same time which had the unit which is called for...Also while your car might have been ordered with a RPO defogger...Do you know 100% it came in with one and the unit in your car now is it???...My guess is it didn't and the unit was ordered through the dealer accesorries and installed...Just to illustrate that point..the "pilot" also calls out deluxe belts (metal buckles) yet the zone rep and original retail owner say the car had the black standard belts which are in the car...


Greg

ba

Greg....good to see you posting again...welcome back as your insight and experience is always appreciated.

Here's what I do know and what I don't. The car definitely came with a rear window defogger option from the factory. It's on the original build sheet which I do have. So I know it came with that option. The blower motor is dated 6 69 which I believe is a June 1969 unit so that would clearly indicate a 1969 unit. No arguement there. Here is where it gets interesting. The slim square hole where the vent fits in the metal package tray/shelf is clearly factory punched. The pattern is perfectly cut/punched and the inside corners are identical to all other stamped out parts on the rear metal package tray. In addition, the raised mounting points on the trunk wall behind the back seat have raised mounting tabs from the factory onto which the blower motor system is mounted. Every raised attaching point is perfectly lined up and the unit fits like a glove including screws, bolts, harness and clips. I don't know if the rear metal package tray and rear metal panel behind the seat in the trunk are identical for 1969 and 1970. What I do know, is that if this is a 1969 unit (and I believe it is) it fits all the factory prepped raised mounting attaching points and holes perfectly for 1970.

I did not restore this car so anything is certainly possible. The car was a frame-off and finished around 1996. Judged at the 1996 Vette Fest, the car won a Silver Spinner and no points were deducted for the defogger unit or wiring, for whatever that's worth. The original restorer who owned the car since 1988 said the unit was on the car when he bought it to restore and could see no evidence that another system had been previously mounted on it. I have seen this unit installed on 1970 GM cars as another has pointed out in this thread with a 1970 GTO.

So does that mean my unit was not a left-over '69 unit installed on a 1970? While I would agree that the bigger vent and other system was installed on 1970 Chevelles, I would not walk up to somebody at a car show, look at my system and defintley say it could not have been installed that way from the factory or not. I have seen too many variations on these cars in the 20 years I've been in this hobby to say never. Just my $.02.

I bet you have a very very rare mid production year, pilot defog car. LOL

I looked at my car tonight and it also has that slim hole punched in the package tray. If you look at (alss) project 69 he's doing it has the same hole. But if you look behind that slim hole you will see a square hole and a round hole in the middle if the package tray. That is where my defogger is and mounts in there using 3 nuts to bolt to the metal grill studs. I think all the 68-72 Chevelle, GTO, Cutlass etc. have the same package tray stamped out. Not real sure what the deal is, but just thought I would add another .02. LOL. Good luck.

Look at page 14 of '69 Chevelle brochure. It shows what looks like a rectangular grille. Beside it is a picture of a Chevelle interior which looks like a Buick seat. Brochures were notorious for having things air brushed in and out as model specifications changed so I don't put a lot of faith in what they show. For what it's worth, our '72 Lemans had the blower that bolted to the underside of the parcel shelf with a plastic rectangular grille.

Jim,

I have also learned never to say never..lol

Here is my take on it...I have owned '69 Chevelles (L78's) but have never owned a car with a factory defogger, so I honestly can't say what the '69 RPO looked like...The dating on the blower motor IMO can't be used one way or another as an over the counter accessory defogger kit would still have had a dated blower motor...

As far as my take on your car..I'm of the opinion it was ordered from the factory with the defogger option..yet when built 2 things could have happened..

1) the car left Atlanta without the option and was invoiced with it...so the dealer went into the accessory book and ordered the kit and had it installed through the service dept..I'd be interested if the acessory book shows a rectangular grate or the narrow grate..This would make sense as the mounting holes would make you think it was done at Atlanta.

2) It is possible there was a shortage of the RPO option when your car was built and a left over unit was used or one from another car line...

Since there is no way to prove this..IMO I'd replace the unit with the typical '70 unit (dated correctly of course) as it follows Gibson's 90% rule...

Either way it is a very nice car..

Thanks BTW for the welcome back..

Greg

Don't know if the unit in a 70Z Camaro is the same as 70 Chevelle but I would suspect so. Don't think I can post pictures as a non member but here is a link to a few shots I posted on Webshots. Hit the "full size" when viewing. Won't give you close up detail but might help. This car is quite original and shows the defroster on the original window sticker. It is metal.


http://community.webshots.com/album/561835621fgTAZc

Don't know if the unit in a 70Z Camaro is the same as 70 Chevelle but I would suspect so. Don't think I can post pictures as a non member but here is a link to a few shots I posted on Webshots. Hit the "full size" when viewing. Won't give you close up detail but might help. This car is quite original and shows the defroster on the original window sticker. It is metal.

Ohhawk's photos:

http://i23.photobucket.com/albums/b400/bendoregon/70CamaroOriginaldefoggerrear.jpg

http://i23.photobucket.com/albums/b400/bendoregon/70CamaroOriginaldefoggerrear2.jpg

http://i23.photobucket.com/albums/b400/bendoregon/70Camaroreardefogger3.jpg

These are pictures of the original ones in a restored 70 Chevelle. It is called out on the build sheet.
I didn't restore this car, so it's possible that the unit was changed, but I think they are original after tracing the history of the car.
This car was built the 2nd week of March in KC.

http://i36.photobucket.com/albums/e43/Rixls6/70SSredL34Chevelle016.jpg
http://i36.photobucket.com/albums/e43/Rixls6/70SSredL34Chevelle017.jpg

I was looking at the pictures of the camaro and was wondering why is the single rear speaker on the wrong side for being such an original car (incorrect speaker also). I believe a single rear speaker was always on the passenger side. Hey ss4real I was just looking and have the complete set-up for your car if you want to make it factory correct. Was just wondering if you have the correct switch or did they install the 69 unit in your car as well. If you could post a pic I would be interested in seeing it.

Ok, I am going to suggest a possibility here in the pursuit of discovery......and post some photos to validate my thoughts. If you look at the defroster vent for the red interior restored Chevelle that Rick posted, you can clearly see the vent is not centered and is mounted towards the driver's side rear (if you measure inside your trunk that is confirmed as the mounting area for this larger set-up is also offset to the driver's side). Next I am going to post my interior with STEREO rear speakers also mounted on the package tray. Those are original speakers in the original mounting position. You can see from the pictures that the red vent grill would overlap on top of the rear stereo speakers, i.e., they will not fit in the same area because the red vent is mounted partially where the speaker and speaker grill are. So, maybe there is a good possibility that Chevelles with rear stereo speakers had the slim vent due to fit, positioning and size issues. Check out the photos below:

Red interior with large grill and no rear speakers:

http://i23.photobucket.com/albums/b400/bendoregon/70SSredL34Chevelle017.jpg

Saddle interior with slim vent and stereo rear speakers:

http://i23.photobucket.com/albums/b400/bendoregon/checklist044.jpg

70SS....my original '70 rear defroster switch on the dash (factory cutout in dash where it's mounted)

http://i23.photobucket.com/albums/b400/bendoregon/checklist048.jpg

Here's an outside shot that shows how everything lines up and the fit, placement and sizing issues that I mentioned. I don't think the big red grill would fit in this setup with stereo rear speakers and it certainly would not make everything line up like this does:

http://i23.photobucket.com/albums/b400/bendoregon/checklist058.jpg

http://i23.photobucket.com/albums/b400/bendoregon/checklist056.jpg

Jim,

I don't think that is the case..The "pilot" LS6 is a stero car as well (speakers in the rear..both sides) and it has the rectangular unit..As did the L34 I owned at one point...Again not trying to cause drama, but I don't think your unit is the unit that the RPO would have left the plants with..or at the very least isn't the unit it SHOULD have left with..

I still say the unit you have is an over the counter GM accessory unit..

my 70ss has 2 rear defogers..... theyre the back windows....lucky dogs

Your switch is indeed the correct 70 unit but it is plainly not in the correct place on your dash. The switch is installed way to close to the radio knob. If you look at drawing C50 in the assembly manual it shows the centerline of the switch and the centerline of the radio opening is 5.60" . This is for the SS dash shell with the part number 13857-67. This measurement will center the lever of the switch between the steering column opening and the radio knob on the left of the radio opening. This is verified after measuring my dash, and plus it just looks better that way. I hope someone will post a pic of some of there switch locations. I have pics of all of this but can't post, if someone could for me I would be glad to take pics.

I looked at the red chevelle with correct factory metal grill and would also say that the vent is not in the correct position. It should be centered in the middle of the car. I actually have the stereo speakers and the correct metal vent and it all fits perfectly, and all installs into the factory stamped openings. Actually I have the U46 option (headlamp monitoring system) on this car and the rear portion of the option exist just fine on the package tray with the speakers (correct for 70) and the correct factory defrost vent(correct for 70). Again if you need pics I would be glad to send them to someone to post.

Thanks 70SS...

That lends support to Greg's theory.....since it's invoiced on my buildsheet, maybe the factory left it off and the dealer added the option/accessory when they received the car because it was supposed to be installed at the factory. Or it was simply restored incorrectly. Or it was installed at the factory with a left over unit or what they had in stock. I wasn't there so I don't know. It wouldn't be the first time for me. My 1979 Trans Am had some options on the invoice and window sticker that the factory left off (I picked the car up at the factory right before my senior year at the Air Force Academy) and the dealer added the options back on when I got home to Colorado Springs. I'm going to leave the set-up as is. At the very least, it certainly gives me more to talk about! Thanks for your input guys.

If anybody else has another thought or opinion...post away.

This is the defogger that is in my 70 ss. Does this look original or is it out of a different model car?

http://i28.photobucket.com/albums/c242/tsnap/IMG_0053.jpg

I believe that is the 68-69 chevelle unit.

'70 should have a metal grille & a metal blower, the grille has 3 studs welded to the backside that passes through the package tray & supports the blower, here's a pic of my '70
http://memimage.cardomain.net/member_images/2/web/278000-278999/278787_10_full.jpg
'71 & up used a plastic grille & blower housing, the grille had 4 studs on the back, these two grilles will not interchange without drilling new holes.

So does anyone know for sure where the slim defrosters were used? I have a complete set-up that was from a '69 Chevelle, and I think it was stock.

Hate to bring it back up. anymore on this issue?

I too wonder if there's any more info on this.I have a rear defrost set up identical to the pics posted by SS4Real in my 70.The thought never crossed my mind that my rear defrost isn't original until seeing this thread.

Them Chevy 70 Rear Defogger units are one enigma. I've been looking one for my 70Z for years. I don't know what happened to mine but it was not in the car when I bought in 76 and should have been there as the Cluster Panel has the switch and there is a low speed Ballast Resistor mounted on the firewall. The Vent Grill is the longer slot type and requires the tube from the blower motor that draws air from behind the rear seat. From what I understand they are the same unit used in full sized 69 Impalas and Eldorados.

I just happened to be replacing my rear shelf today on my 70 ss. I read this topic yestreday and looked closely at the cutouts.It has both type of cutouts for the slender defogger and the rectangle one which mine has.Also noticed other factory cutouts on each side which look like they could be for rear shoulder harness.