Chevy Astro AC/Heater Blower Vent con...

United States

#81 Mar 22, 2008
98 astro no a/c.
no blower/comp. just deadcould this be selector switch?
how do you check this?


#82 May 18, 2008
It was 104 deg yesterday. I had forgotten that the AC / Air-to-the-front-issue hadn't been resolved...decided to do whatever it took to get this problem behind me...found this blog / site...took the initiative...I haven't had air to the front of this van for well over a year...3 ft of 5/16 od vac. line later ($3.99 plus tax) the AC to the driver / passenger is a thing of the past...Thank you!

Warren, NJ

#83 Jun 2, 2008
I am having this same issue, I am going to try and fix this problem this afternoon or tomorrow. Everything works great except it only blow air to the defroster.
Luis Beltran

Richardson, TX

#84 Jun 14, 2008
Hey guys. I finnally got my 99 Chevy astro AC working again. Here I posted some picture to help you find the culprit hose @N06/?saved=1
Luis Beltran

Richardson, TX

#85 Jun 14, 2008
Ups bad link HERE IT IS!!!
Luis Beltran

Richardson, TX

#86 Jun 14, 2008
Chevy astro A/C blowing only defrost position regardless of A/C swith position. Bad vacum plastic hose (brittle and broken off) Find it and replace it very easily with almost no tools and in just minuts. follow this link to images I uploaded in

Tipton, IN

#87 Jun 26, 2008
Excellent info. Thanks. My A/C just quit coming out of the vents on a trip. Left it on high and the rear on high and it was just enough to keep us from baking. Found the hard plastic line melted thru that runs from the tee next to the evaperator to the manifold fitting on the driver's side between intake and valve cover. Removed it and it broke in several places. Replaced it with OLD fashioned rubber vac line. Works great! Thanks Again!!

United States

#88 Jun 27, 2008
I would just like to thank the people that posted here regarding the repair of the vacuum line enabling the heat/ac zone switch to function properly. That was exactly what was needed in my case and saved me $145.00. Thanks again

Atlanta, GA

#89 Jun 28, 2008
the astro ac heater control switch no work just comeout the air in the defrost

Atlanta, GA

#90 Jun 28, 2008
2000 Chevy Astro. Suddenly AC/Heater vents don't blow except for the defroster vent on the dash. The control switch operates to turn on/off AC, but will not select the different blower vent configurations. Stays on windshield defroster blower vent.


#91 Jul 12, 2008
ac blower only work on 3 setting not high please help me ,thank you.

Longmont, CO

#92 Jul 17, 2008
You would think by now the General would have figured things out. Long ago I had a 1994 Grand Am with the same issue (only blowing out defroster vent) and traced a hard plastic vacuum line around the battery (left front of engine compartment) and the rubbing had chafed a hole in it. Cut the hard line and added 2" of 5/32 vacuum hose to connect the two pieces, worked great.

Across all vehicle and model lines this seems to be an oft-recurring problem. As I say, you'd think GM would have figured out a better way to do this by now.

Take care and enjoy the ride,


#93 Aug 5, 2008
Hey guys...just recently had similar issue with my vents in the front stopped blowing. Had the hoses which were worn..replaced. Now I have a new issue...the high switch is no longer working...low and second two settings are fine but will not work when on the high position. Do I need a new control swtich thingy thats in the console? My astro is a 2000 model.

Spring, TX

#94 Aug 11, 2008
I had the same problem with air only coming out of the defroster vent, regardless of the switch setting. With the help from this forum, I was able to locate that vacuum line, and sure enough, about 6" of the line was completely gone. AutoZone gave me a piece of hose that I was able to splice in, which resolved the issue. Hardest part of the whole process was figuring out how to get the inside engine cover ("doghouse") off. Thanks a million to all of you for the tips and suggestions. No telling how much money that saved me.

United States

#95 Oct 28, 2008
'99 Chevy Astro 4.3 V6 Same problem with air at floor and defrost only. Same solution, vacuum line

United States

#96 Oct 29, 2008
I have the same problem the lower speeds run but not the high speed. see if you blower works on every speed except high, if it does there is a relay under the hood on the pass. side, bump that relay to see if it comes on. I read that the high speed fan is a relay and the low speeds are a resistor type.
john williams

Fort Thomas, KY

#97 Nov 15, 2008
i have a 1998 astro cargo van/heater problem/ i check the heater core/themostat/hot water heater vale/ all works/ but i get cold air/(i turn the switch on the dash from hot to cold back to hot/i checked under the glove box to see if i hear the door heater open and close) i cant hear this happen. does anyone know how to repair the heater door to let hot air into the cab.

Tonawanda, NY

#98 Dec 4, 2008
John, I'm having the same problem with my 99 astro, just changed the thermostat and cap,no real help from that, hopefully someone has a cure, I'm thinking of wedging the heater door open for the winter. Going to look for it tonight
Terry K


#99 Jan 2, 2009
John and Yasure.....Having the same problem on my 1998 Astro. I know the vacuum line that has been discussed earlier is bad, but haven't been able to get to the hose end that hooks on to the engine. temperature gage is acting erratically....going up to red line....then dropping back to normal...up & down constantly. I have stopped and removed radiator cap, but it doesn't seem to be boiling noise or steam. I get heater heat soon after I start driving, but a little later it just blows cold air. I wonder if the vacuum hose could be causing the problem. I purchased a new thermostat but haven't replaced it yet, because I'm not sure if that's the problem. BTW....what is the DOGHOUSE?

Northbrook, IL

#100 Apr 4, 2009
the problem is a 1/8 inch vacuum hose that cracks, if you hit a bump this hose bounces up and or down and seals the leak temporally. Very hard to see the end closest to the fire wall. Hose runs from the front right (passengers side back at a 45 angle to the left side of the carb) If you don't want to remove the dog house cut the hose in half and get some heat shrink tubbing. Slip this over the hose all the way to the back. You have to remove the air filter and hose to do this. Then slip a second shrink wrap to the front half section. Mate the two cut hose ends and over lap the heat shrink. I used a hand held torch to set the tubing. Be sure to push hard on that first section to overlap the rubber plug, you can feel the overlap but can't see it.
This quick fix last for two and a half years. Now if some one can tell me how to find where the heater vacuum hose hooks to some black ball that is impossible to see or reach.

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