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GMC Safari/Chevy Astro Heating / Cooling



  • 97xpresso97xpresso Posts: 249
    It's a vacuum line on (over and too close to) the engine which was damaged. You have to have really long arms to reach from the front hood area.
  • cobcob Posts: 210
    Is it easier to reach by removing the doghouse?
  • tkwtkw Posts: 29
    Hi 97 xpreeso:

    I have the same problem on my '98 Safari. Can you tell me more about where to locate this vacuum hose? Is it accessible from inside with the doghouse removed? What make you decide not to replace it with new parts?

    I have got hold of a Haynes Repair Manual but it's no help at all. I too like to investigate more to decide if I have to take the dash out. Thank in advance for your advice!
  • 97xpresso97xpresso Posts: 249
    The reason it was not properly repaired is that it was a company vehicle that they did not want to spend $ on. I now drive a 2005 Astro, and the air actually comes out the dash, but for how long? A co-worker claimed he had success with a neighbors Astro and I watched him try to fix mine. I believe if the proper diameter hose was available it would have worked. Standing in front of the van the hose came out of the dash just off center towards passenger side. It then curved downwards 180 degrees across the top of the engine where heat deteriorated the hose. It probably would be easier to remove the engine cover. Good Luck.
  • cobcob Posts: 210
    I found the vacuum line on my 97 that had broken. The line starts over behind the a/c evaporator on the passenger side of the van right in front under the hood and goes across the motor and hooks to a fitting on the intake manifold behind the a/c compressor. I routed it above the air cleaner to keep it cooler instead of along the intake manifold where the factory routed it, time will tell if this lasts. That line fixed the problem and now the air comes out wherever the knob is set to on the dash. I removed the air cleaner cover and the tube that connects it to the rest of the air intake and it was easy to fix from right under the hood. The vacuum line is a real small diameter plastic tube with rubber connectors molded to each end. You can't hear the vacuum leak with the engine running since the hose is so small.
  • I love my astro but am having some probs at 140k. My wiper motor has gone intermittent. (A bad thing in the daily fog drizzle we have here every day this time of year) I saw a fix earlier that suggested re soldering connectors at the circuit board. Can someone tell me the location of that board so I can find it without having to go through the trouble I did locating the wiper motor? Click and Clack said it was under the dash by the glove box. So I hauled everything out only to find the motor under the hood which required cutting of the protective housing to remove.

    When the motor came out I dissected it expecting to find worn or hung brushes. I had neither! Everything looked fine. I had tested and found voltage to the unit before removing it, but now suspect that maybe the voltage that registered on my digital Radio Shack cheapie maybe didn't have enough amps to turn the motor.

    Any ideas?

    My directional air controller has failed as well. But from reading previous fixed I'm going to have to look at the vacuum line.

    My A/C left sometime last year and I can't tell if the clutch is engaging or not. It worked fine always good and cold until that point. I would appreciate some advice on how to begin trouble shooting that system.

    Why do I love her with all these problems? Unlike my wife, I've had her since new, and she's proved WAY more reliable and predictable.

    Thx in advance for any and all advice.
  • cobcob Posts: 210
    Check with you r dealer about a recall on the wiper motor. GM recalled all of them in trucks and vans over about a 3-5 year period 96-99 or something to that effect. I had mine replaced in the 97 for free last year. As I explained before the vacuum line is an easy fix. You can tell if the clutch engages because of the extra noise it creates engaging and disengaging. The engine also changes speed up and down during that process. Good luck on the repairs.
  • tkwtkw Posts: 29
    I've got to try this one. I should have check this forum before I went on the wild goose chase under the dog house last weekend. I tried to tackle this same problem from under the dog house without success. BTW, does anyone know how to remove the dog house without taking the passenger seat out. I can only manage to turn to side way to get access to the engine.
    It was unseasonably warm last saturday,over 90 degree F. We usually don't get this weather until way into July. Now, DW is threatening to file for divorce if I don't get A/C to come out from the dash outlet. :mad:
    Anyway, thank cob for the tip.
  • tkwtkw Posts: 29
    Hi cob:
    I found it. It was broken in two places and lying on top of the thermostat housing. There's actually a flat spot on it resulted either from heat or rubbing against some moving parts. Without your descriptive & helpful explanation, I'd never suspect this stiff dingy 1/8" hose is a vacuum hose. I was looking for a 1/4" flexible rubber hose all along. BTW, did you buy the replacement hose from auto parts store in bulk or you have to get it from the dealer.
    Thank you in advance!!!
  • tkwtkw Posts: 29
    I yanked the hose from its fitting at the evaporator end and took it to Canadian Tire this morning. The guys at the service counter have never seen such a vacuum hose. No luck. I will try a few other auto parts store before I hit the dealer b/c they are normally three times the cost. Suggestion anyone please?
  • cobcob Posts: 210
    I got my hose from the dealership. I then routed it over the plastic air intake to keep it cooler so it would not melt again. I guess they make repair kits for the hoses but it is a cheap part even at the Chevy dealer. You can get the doghouse out without removing the seat I have done it a few times. You have to move the seats back all the way and pull the cover straight back. When you lift it out you will have to compress the corner of the seat cushion to squeeze it by and it takes alot of jimmying but it will come out. Putting it back on is a little easier.
  • tkwtkw Posts: 29
    I placed an order at the dealer this morning and picked up after lunch. It was surprisingly cheap, under $10 CAD. I tried 3 autoparts store to try to get longer ones so that I can reroute it out of harms way without success. I know you have to get the whole assembly from the dealer with the end fittings and afraid that it may be in the range of $50. How often you can get away with $10 from the dealer?
    The downside is the re-routing option will be limited by its pre-determined length (800mm). I read it here that a fellow member has replaced his from under the hood. I will try my best not to touch the doghouse. I did it last weekend and it really sucks!
    Anyway, thank you for your help and wish me luck!
  • tkwtkw Posts: 29
    Hi guys:
    A big thank you for all of you here who shared their experience. Here's my update.
    I replaced this vacuum hose thing from under the hood this morning with some difficulty. But it is doable if you have small hands like me. At one point, I almost have given up and attempted to take the dog house out. From under the hood, first I removed the air filter, air intake housing and the electrical connectors. Then I picked up the old hoses piece by piece on the manifold and traced it to near the back of the A/C compressor. I had the rubber fitting held between my left index finger and middle finger and stuck there. I didn't have any room to get my thumb on it to pull it out. I wondered it'd help if I have all thumbs. ;)
    To avoid wrestling with the dog house, I reached in and removed the wing nut securing the metal bell housing over the throttle body. This gave me an extra inch or so to pull the rubber fitting out. The new hose from the dealer is barely long enough to allow rerouting over and away from the engine. And now that we finally have dash A/C, it is raining out there today.
    Sorry for the long post. To keep the record straight, this so call vacuum hose is actually a vacuum signal tube for HVAC control. Its GM part no. is 15967970. It is 1/8" O.D. x 800 mm long. I hope this would help those who has this nagging problem.
  • wmrherewmrhere Posts: 1
    In 2 words - vacuum line.

    I have a 97 Safari which has had the same problem. The factory supplied tubing is less than 125" O.D., and runs from the top of the manifold about 20 - 30 inches. In my case it was glossy black and really brittle after heat exposure. I ultimately replaced the entire length, after 2 unsuccessful problem area replacements.
  • cobcob Posts: 210
    I have a 1997 that is a conversion van by Glavel. The rear heat/a/c was installed by them at an aftermarket company. There are freon lines and heater hoses running to it so I would assume it would work for both a/c and heat. However the control for it is just a 3 speed fan switch. The unit always blows warm air no matter what temp I have set on the dash control. The a/c portion is an extra evaporator connected to the factory unit and there is a sticker under the hood that states they put in x amount of freon at this company. My dash factory a/c blows cold (so I know that the freon is not leaking)but the rear one blows warm air. Is there a valve somewhere in the system that may be stuck for the temp control to the rear unit? If there is where can it be located? If anyone else has this setup or has some answers please reply, thanks.
  • Claire@EdmundsClaire@Edmunds Chicago areaPosts: 968
    cob, you might also want to bring your questions to the folks in the Climate Control Problems: All Cars Forum to see if they have any answers for you.

    ClaireS, Host
    Coupes & Convertibles | Vans & Minivans



  • tkattkat Posts: 1
    Look here for the Vacuum hose issues on your AC, it may just be cooling your feet, as the diverter is not getting any/enough vacuum. As to the wiper motor, unbolt it partially, and clean the copper grounding strap you'll find on one of the mounting bolts. It's a poor combination of two dissimilar metals, and corrodes after about 5-7 years. Result: no ground, no wipe.
  • jpc47jpc47 Posts: 62
    Turned out to be a melted vacuum line going to the ac control. My mechanic spliced a piece in and now I'm fine.
  • Just last week my 96 astro will only blow air out of the defrost and floor, like it is stuck on that setting even when i try to make it blow out of the dash vents.

    Where do I even start to fix this problem???

    Thanks allot!
  • cobcob Posts: 210
    Look back a couple of pages and you will see many posts on this issue. It is a common problem that the plastic vacuum line from the passengers side front of vehicle by the a/c components that runs across the engine to a vacuum port on the drivers side of the motor. The line melts and you lose the air settings. It is a cheap part and try to route the replacement line over the plastic air intake so it doesn't melt in the future.
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