1997 SSE with electronic climate control.

This problem started out a few weeks ago when we started getting very high temperatures in our area, (in excess of 100 each day). When I start the car on a hot day, the A/C blows through the defrost only for varying lengths of time. Sometimes it is for a minute or two, and other times, it may take 10 minutes before it will blow through the main A/C vents. Then it will gradually start blowing through the main vents until it is exclusively going through the mains. A/C cools just fine. Air is very cold. Just goes through this routine. It seems the hotter it is, the longer it takes.

Any suggestions?

Thanks.

Hi read the link in this thread entirely.. it'* long.. but should fix up any issues.

http://www.bonnevilleclub.com/forum/...ght=blow+vents

Does it happen when you manually command the A/C on, through the center vents, with fan speed on high? Does it take longer to switch to center vetns on very humid days?

I remember reading about a built-in lag time, possibly, depending on how humid and hot the air is outside, to allow the air to be dehumidified/cooled before blasting a person from the center vents. Still, I believe it should be just 40-45 seconds.

when I first start the car, the air is coming from the defrost and floor registers, and not the main vents. After a few minutes, it slowly starts changing to the center vents, and slowly stops coming out of the defrost and floor registers. Before the change over, the manual controls on the ECC do nothing. But once it changes the the center registers, you can use the manual controls and change to defrost, or floor, but when you come back to the center registers, it goes through the same routine as when you first start the car. It won't blow out the center, then goes through the slow change from defrost/floor to center vents.

I am certain now it is a vacuum issue. I am hedging more toward a crimped or impeded line instead of a disconnected or leaking line. It seems to me what is happening is that there is some vacuum, but not enough at first, and then the pressure has to build until it finally has enough to change. I may be wrong, but that seems to be the most reasonable hypothesis. I have to start tracking it down tomorrow. It is really a drag to get into the car on a 110 degree day and not be able to feel the air for 5 minutes or more.

Thanks for the links above

Well, I tried my best to find the vacuum leak, and I couldn't find one. So I took it to my local Pontiac dealer and they determined the problem was the "programmer". They said it wasn't the head unit in the dash but something up under the dash on the passengers side. Does anyone know what that is? They wanted $495.00 for the part, and about $150.00 to install it. So, I need to figure out where that is, and how to change it out myself. Also, I need to find one I can buy cheaper. Does anyone have a part number?

Thanks

Gary

Whoa.....before jumping straight into a new programmer, you may want to check the vacuum connector on the programmer for crushed/pinched nipples (hold off on the jokes) that is dicsussed in the links Billboost provided for you. The connector (clear and black plastic junction that connects all the different colored lines) is not sold as a seperate unit, only with a new programmer, but can be "fixed/bypassed" for about 79 cents (that is what the tubing cost me.)

The programmer is located under the hush panel behind the passenger side of the dash INSIDE a black box/case. If it were me (and it was last summer), I would follow the advice in the other threads and replace the connector with new lines before I spent $$$$$ on a new programmer.

Also, have you checked the vacuum supply canister under your front passenger side fender (underneath the car)? Make sure it and the connections to it aren't leaking. That is the reserave tank for vacuum operated systems in the car.

Well the dealer tore into the system and found that (in their opinion) that the programmer is bad. They say I need a whole new programmer. I don't know enough about this to know otherwise. They say they checked the connections on the progammer. I can only trust that they did. I am open to suggestions. I have read that thread you are talking about, and I saw the picture of the programmer. So I know what I am looking for. But they say it is bad and needs a new one. Are they trying to sell me a big ticket item? I guess they could be, but I don't know for sure. I'm open to suggestions. If it is that, are there any work arounds that I could use till the end of summer. And that is apparently far off for use here in Oklahoma. It is currently 105 and the long term forecast is for 100+ for several more weeks.

There is no way to know if they are giving you any bad information or trying to sell you a big ticket item. The only way to know for sure is to use a Tech II scantool (which is costly, so only repair facilites usually have them). I only offered up replacing the connector with vacuum tube for 79 cents, as a possible thing for you to try before you spend big $$$$.

If it is the programmer, then I would think you can install the programmer, yourself, if you find one. A junkyard or gmpartsdirect.com may net you one that is cheaper than buying directly from the dealer.

As for a short term fix, there is a way that many of us have rigged the airmix door closed for full A/C, but aI don't know if anyone has come up with someting to force the air out of the center vents. Everybody that has had the center vent problem fixed it with the "connector" replacement or another component was bad, but here is the fix:

http://www.bonnevilleclub.com/forum/...ht=redneck+fix

Well, here is an interesting update. First, I found the programmer on gmpartsdirect.com for 364.change. I started calling around to salvage yards, but as of yet, I haven't found one. Anyway, I drove out to the dealership to pick up my car. I asked them how they determined it was the programmer and they said by process of elimination. Did vacuum line tests and found no leaks. Checked the ECC unit in the dash and it was fine. Found no error codes (didn't say what they were testing). So, the only thing left was the programmer.

Anyway, I paid them $30.00 for the diagnosis and walked out to my car. It was 105 degrees at the time. Got in my car, started the engine, and low and behold, I had cold air out the center vents within 2-3 seconds. About the length of time it takes for the system to determine what is necessary for cooling the car, and for the door to change from defrost to center vents. Drove it home 30 miles. Worked like a champ. Stopped at my folks house to say hi, and killed the engine, and I heard the vent door close back to defrost. Started the engine back up, and air came out the center vents. Killed the engine again and went into my folks house. Visited for 15-20 minutes and then came back out and started the car....air out the center vents...just like it is supposed to be.

So, only thing I can guess is either a bad electrical connection, or a bad vacuum hose connection that was corrected by the technician disconnecting and reconnecting the programmer. Either way, I will hold out hope that this fix is permanent. I wasn't looking forward to dropping 364.00.

Thanks to all for their input. I will keep you posted as to whether or not this is a permanent fix.

Gary

That'* great!!!!!!!!!!!

Sometimes, all it takes is a little fiddling or a change in outside temperature to make a good connection. I hope it works for you. If you end up needing to try some of the other fixes, let us know, and we will guide you through it.