Gen I Grand Prix Owners - question on defroster

[jmgtp]

I'm trying to determine if I have a problem with the blend door or if this is normal..

When I put defrost ON I get air out the defroster vent, the pillar vents, AND at my feet. A LOT by my feet actually. This is on defrost only, not the split button for feet/defrost.

Normal or not? I feel like its not normal and I want more air on the glass to clear it faster. I'm going to check the vacuum harness to be sure I get good vacuum since that could be a problem, but it has no problem switching to the vents only or feet only. Its just that on Defrost I'm still pumping quite a bit of air to the feet.

Also found out I only have 3 working defrost lines in the rear glass! The joys of a 20 year old car.

[SappySE107]

They all throw it on your feet constantly from what I have noticed over the years. My 92 wasn't put back together properly so it just blows where it wants on any setting now:P

Check the W body owners group under the community tab Just started it, would be a good place for this

[jmgtp]

I'm struggling with it now because its that time of the year where my windshield is foggy in the morning, and my a/c system which has performed flawlessly for 20 years has finally seemingly lost its charge. At least it seems like the air at the feet is a normal thing. It manages to clear it with just air movement and sometimes a bit of heat thrown at it but not the instant clearing like with the a/c compressor running. I'll be doing a r134a conversion either over the winter or in the spring.

And on the community area - that's awesome, I joined. You can move this thread there if possible.
It's one thing I wished this site always had - car specific place. For questions just like this that have nothing to do with a 60v6 but to a specific car, rather than posting it in an off topic area now it has its own space. Is this feature advertised elsewhere on the site? Get the word out there, I had no idea it was there!

btw, I received the LX5 TB adapter which will be installed tomorrow - I should be ready for some tuning by Monday.

[SappySE107]

I posted in off topic about the group. Anyone can start a group for their platform if they like.

[bszopi]

Check the W body owners group under the community tab Just started it, would be a good place for this

I'll probably add a tab at the top, next to gallery, garage, etc., as a link to the groups so that people will know they are there and perhaps start using them more.

[TGP37]

Not sure if this applies to your vehicle but.....

Sounds like a vacuum leak to the vent/blower. You may have a vacuum reserve on the vac line for the blower control connected with a 'T' and check valve. My reserve was cracked and caused a huge vac loss. Since bypassing it my vent control is returned.

You may have a slight vac loss from a crack. Not sure but it is something to check into.

[jmgtp]

I removed the reserve canister years ago. Weird thing happened - I gave it some throttle a few nights ago (the defrost was on) and it redirected the air to 100% on the front glass like it should and none on the feet. Next time I drove the car with the defrost on it it was back to some air on the glass but a lot still on the feet. Something is definetly weird here!

I put a handheld vacuum pump with gauge on the vacuum line under the hood that leads to the hvac controls. It held 20" of vacuum with no leaks. I'm starting to wonder if the controls are culprit.

[jman093]

I removed the reserve canister years ago. Weird thing happened - I gave it some throttle a few nights ago (the defrost was on) and it redirected the air to 100% on the front glass like it should and none on the feet. Next time I drove the car with the defrost on it it was back to some air on the glass but a lot still on the feet. Something is definetly weird here!

I put a handheld vacuum pump with gauge on the vacuum line under the hood that leads to the hvac controls. It held 20" of vacuum with no leaks. I'm starting to wonder if the controls are culprit.

If there are well and truly no vacuum leaks, I would maybe say the actuators or doors are sticking or something. Hard to say for sure. All I've ever seen cause problems are vacuum leaks.
If you want to fix your rear defrost, try this:

http://images.bizrate.com/resize?sq=500&uid=1719115829

It can fix broken grids. I bought some at O'reilly for my sister's Z34.