Defroster inop ???

RobM · Post by **RobM** » Fri Dec 07, 2007 3:01 am

I'm moving this to the serious question area. . .

Okay, my heater is working. I've got heat all in the cab (front & back seat vents) and up to my feet. However there's nothing coming up to the defroster. I've got new pipes up there from the local shop but nothing comes out. I've hooked up a shop-vac to see what's going on but it just blows into the pipes and goes nowhwere--seemingly.

So the heat runs through the side-channels to the front, but what path does it follow to get from there up to the defrost outlets? Somewhere in there it seems to stop movement.

Signed, 'My feet are burning but I can't see' . . . (Sorry, I couldn't resist that one.)

Post by **jmartini** » Fri Dec 07, 2007 4:52 am

The pipes feed up the channels at the rear of your trunk to the side vents and then to the defroster. The pipes may be broken in the channel so you need to get a flashlight and look. You need to remove the cardboard or plastic covering in front of your wiring to make sure the other cardboard tubes are also hooked up. My guess is that the tubes are disconnected or broken. Give it a good look over and I think you'll find the problem - let us know what you find.

RobM · Post by **RobM** » Fri Dec 07, 2007 6:14 pm

jmartini wrote:The pipes feed up the channels at the rear of your trunk to the side vents and then to the defroster. The pipes may be broken in the channel so you need to get a flashlight and look. You need to remove the cardboard or plastic covering in front of your wiring to make sure the other cardboard tubes are also hooked up. My guess is that the tubes are disconnected or broken. Give it a good look over and I think you'll find the problem - let us know what you find.

Heat gets to Driver & passenger front feet-- then vanishes. Inside the trunk there is a nozzle coming off each of the inside-corner defroster vents. These do have pipes hooked to them that lead to the center defroster. Pipes are good and blowing air through them with a shop-vac proves continuity. Left hose feeds the left side of the center defroster, right hose feeds the right side.

The break in air flow is between front foot vents and window corner defroster vents. (Anyway to access the channels feeding these???)

I even shoved a steel snake a foot or so down the corner vents and found them clear as far as it would go. There seemed to be a bend at that point. Somehow there's no air getting through there either to the window corner defrosters or, of course, the hoses to the center defroster.

(I'm wondering if some previous owner replaced something with pieces that completely blocked these channels.)

scruffy · Post by **scruffy** » Fri Dec 07, 2007 6:37 pm

or a mouse found a home. you may have to snake the old tubing out and replace it. trying to save it is virtually impossible for it gets so brittle over the years.

RobM · Post by **RobM** » Fri Dec 07, 2007 6:51 pm

scruffy wrote:or a mouse found a home. you may have to snake the old tubing out and replace it. trying to save it is virtually impossible for it gets so brittle over the years.

No tubing between inside front vent and trunk. Or if there is, I can't find it and I tore out all the carpet looking for some sort of access port to the chanels up there.

Post by **jmartini** » Sat Dec 08, 2007 4:07 am

So it sounds like the tubing is missing from down in the front heater channels to the side vents...right? It's hard to follow without pictures. Those tubes come up from the rear corners of the trunk. If they are missing it won't be too difficult to replace and then you will be back in business as far as defrosting the windshield.

RobM · Post by **RobM** » Sat Dec 08, 2007 10:58 am

jmartini wrote:So it sounds like the tubing is missing from down in the front heater channels to the side vents...right? It's hard to follow without pictures. Those tubes come up from the rear corners of the trunk. If they are missing it won't be too difficult to replace and then you will be back in business as far as defrosting the windshield.

- Upper corners of the trunk or lower?

- What I currently have is two brand new pipes running from the nozzles in each upper corner of the trunk(backside of the side vents). These are hooked to the defroster.

- Side vents don't work, therefore the center defroster doesn't work either.

- I back-blew these nozzles with a rag sealing the side vents (hoping for a puff of dust or some indicator they had cleared) but I could detect no air motion inside the car.

- There is, seemingly, no pathway to the side vents (and therefore no heat to the side vents or center defroster.)

- Is there any access to the heater channels that feed the side vents??? (I mean, without cutting the car in half.)

RobM · Post by **RobM** » Sat Dec 08, 2007 11:09 am

jmartini wrote:So it sounds like the tubing is missing from down in the front heater channels to the side vents...right? It's hard to follow without pictures. Those tubes come up from the rear corners of the trunk. If they are missing it won't be too difficult to replace and then you will be back in business as far as defrosting the windshield.

- I keep looking for some sort of nozzles in the lower corners of the trunk to come up and Y -off to feed both the side vents and the center defroster. that would make sense to me. But I've felt all around down there and I can't find a hole or a nozzle for anything to hook to. To really see I may need to pull off the hood.

- As it is, it looks like the hoses are making an empty loop from the side vents to the center vent but nowhere else.

Post by **jmartini** » Sat Dec 08, 2007 11:58 am

Sounds like they are missing...don't take your hood off though, just grab a flashlight and shine it down to the heater channels, you will see where it hooks up. Let me know if you have any luck with the flashlight. I'd send some pictures but my VW is currently in storage.

RobM · Post by **RobM** » Sat Dec 08, 2007 5:27 pm

jmartini wrote:Sounds like they are missing...don't take your hood off though, just grab a flashlight and shine it down to the heater channels, you will see where it hooks up. Let me know if you have any luck with the flashlight. I'd send some pictures but my VW is currently in storage.

Nothing down in the bottom corners of the trunk. I've looked and felt around there. Are there supposed to be nozzles for the tubes to hook up to down there? If there are, are they replacable?

RobM · Post by **RobM** » Sat Dec 08, 2007 11:27 pm

RobM wrote:
jmartini wrote:Sounds like they are missing...don't take your hood off though, just grab a flashlight and shine it down to the heater channels, you will see where it hooks up. Let me know if you have any luck with the flashlight. I'd send some pictures but my VW is currently in storage.
Nothing down in the bottom corners of the trunk. I've looked and felt around there. Are there supposed to be nozzles for the tubes to hook up to down there? If there are, are they replacable?

Ah! I remembered to check it while the heater was warm and running this time (It's usually been pouring rain or the engine's cold when I'm working on it.)

If I reach down into the empty trunk space I can feel the heat coming out. There's just nowhere to attach any pipes to the channels

(explaining why I couldn't see anything.)

Post by **jmartini** » Sun Dec 09, 2007 4:12 am

If memory serves me correctly the hose should slip over the heater channel, Here's a link to the correct hose for the application:

http://www.wolfsburgwest.com/cart/Detai ... 113819723A

scruffy · Post by **scruffy** » Sun Dec 09, 2007 8:05 am

the only access to the heat channel is by a series of punched holes under your floor mat which is glued to the tunnel of your heat channel. don't quote me now I might be thinking of my 69 super! but you shold be able to feel them through the vinyl. they do indeed hook to the front of your heat channel. the holes are something like 3/4" dia. so you should be able to snake new ones on.

RobM · Post by **RobM** » Sun Dec 09, 2007 4:19 pm

jmartini wrote:If memory serves me correctly the hose should slip over the heater channel, Here's a link to the correct hose for the application:

http://www.wolfsburgwest.com/cart/Detai ... 113819723A

Thanks for the link. No nipple on the heater channel for the hose to slip onto. Just an empty hole. I may have to fabracate one.

I'll let you know what I come up with. At least I'm moving in the right direction. I know what's missing. (I also know that the mechanic who hooked up the pipes didn't know what he was doing.

)

That's okay, I'm learning as I go.

RobM · Post by **RobM** » Sun Dec 09, 2007 4:28 pm

scruffy wrote:the only access to the heat channel is by a series of punched holes under your floor mat which is glued to the tunnel of your heat channel. don't quote me now I might be thinking of my 69 super! but you shold be able to feel them through the vinyl. they do indeed hook to the front of your heat channel. the holes are something like 3/4" dia. so you should be able to snake new ones on.

Thanks. I don't need to trace any blockage in the heter channels now, since I found the outlets. I just have to find a fitting to hook a 1.25 in heater pipe to a .75 in hole. If the local import parts place doesn't have an adapter, I can probably just make one out of copper and fit it on.

Oh, and a "Y" too. It's funny how all sorts of places sell VW heater pipe, but no one seems to carry the "Y"'s to go with it. Again, I'll probably just fit a copper water pipe fitting to replace the "Y" if I can't purchase one.