Last post on Oct 13, 2013 at 2:35 PM
You are in the GMC Safari & Chevy Astro
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GMC Safari, Chevrolet Astro, GMC Safari Cargo, Heating / Cooling, Van
#140 of 371 chevy astro no heat.
Dec 05, 2007 (5:40 pm)
i just bought a 1996 astro,the seller told me that the heat wasnt working, so i new i had something to fix.i had to replace the water pump,it was leaking.i also changed the therostat,heater resister,fixed the vacum leak from ac to the manifold,checked the heater core and still no heat.all the control setting seem to be working,every time i turn on any setting cold air blows out.i think it might be the door that the outside air comes in isnt closing,any advice to help would be very welcome.also where is that door?
#141 of 371 Re: Astro Nightmare [gr8pumpkin]
Dec 14, 2007 (10:17 am)
Hi; I'm Curt and I have the same problem. Did You ever find a diagram? and if so where is it?
#142 of 371 Rear heat issue
Dec 27, 2007 (1:07 pm)
My rear fan works fine, but always cold. I checked the vacuum lines in the engine comp. that control the valve that lets hot water go to the rear heater. If the rear heater core was clogged, would both lines be cold, or would the input be hot and then the return cold? Seems if the core was plugged, no water would move anywhere. And how can you test the valve? It seems fine, all hoses connected, etc. Anyone ever have a core plug? I haven't...thanks
#143 of 371 Re: Heater only works sometimes????? [johnpettybone]
Dec 28, 2007 (7:30 pm)
I am having same problem with my Chevy Astro '97. I have flushed coolant, replaced thermostat, I think it may be the water pump - although the standard tests for this seem to indicate that it works. My car never over heats, and the gauge indicates that the car generally operates in the 150 degree range. The thermostat is set for 195 degrees. The gauge goes up to 210 and slightly above, then drops suddenly down to the 150 - 170 range. I have checked the lines to and from the heater core, and liquid is flowing through it. The lower hose (in to the heater core) gets warm, but the upper is cold. I just drove cross country, and the heat worked intermittently (mostly it just didn't work). The temperature outside has been cold (in the teens), and the heater works more often when it is a little warmer (40's and above).
If anyone has found a solution, I would be very interested to hear it.
#144 of 371 Re: Heater only works sometimes????? [brad70]
Jan 04, 2008 (8:03 pm)
i had the same problem,follow the hoses from the heater core to where they meet vat a temp.control valve.what the valve does is it opens to let coolant flow to the core.check and see if it is stuck,there is a little plundger in there that you see the top of it to see if it as moving in or out.if it is working fine the tryt flushing the core,thats really easy,just disconnect the hoses to the core in the engine compartment between the ac and the pass fender.take a hose and hold it on one tube and then the other.its a little messy.dont forget that when you fill it back up with anti freeze run it for a while to let the core fill back up.you will need to top off the radiater
#145 of 371 astro van playing tricks now
Jan 04, 2008 (9:29 pm)
I wrote a few posts ago about the vacuum problem in my 2000 Astro. That problem is now fixed but now (1 month later) there is a new problem. When I put my foot on the gas, the air stops blowing from the vents and goes back to the passenger side bottom and defrost only. If I take my foot off the gas, it will start blowing out the vents again. Whats more is that the rear heat turns cold with my foot on the gas and goes back to warm when I take it off. This is a weird car.
#146 of 371 Re: Heater only works sometimes????? [jet460fd]
Jan 07, 2008 (7:16 am)
The control valve is up in the engine compartment attached to the AC Evaporator housing, isn't it? I found mine, but cannot figure out if it is faulty. I did have issues with my rear heat low/med/high switch, and it seems to have failed. I did get it pulled apart and found a way to jumper 2 pins so I can get the rear blower to run on high, but have only cold air-because the water line is cold. So, I assume that the plunger unit is faulty, as my front heat is fine, and new radiator etc...You said to disconn the hoses betw the ac and pass. fender. could you email me at erik.lane.broekhuizengmail.com so you could walk me thru this? Thanks
#147 of 371 Baby, it's cold in here...Safari heater prob...
Jan 07, 2008 (1:59 pm)
Hi folks, been finding some great info in the forum, but still can't get any heat. I pulled out the doghouse, and sure enough found a rotted vacuum line. It ran from a T on top of the engine down to another T on the pass. side. That T went into a connector on the
fender wall and a skinny plastic line that went into a wire bundle. I replaced that line, but it didn't help. Any other ideas?
#148 of 371 Re: Baby, it's cold in here...Safari heater prob... [anim8r21]
Jan 07, 2008 (4:53 pm)
anim8r21, you said you can't get any heat, but does that mean the blower isn't blowing heat, or the heat is coming out of the wrong vents or what? You said you replaced a vacuum line, which one? The one from the engine to the vacuum ball canister, or the one that goes into the wire bundle to the selector switch on the dash?
Need more info on whether you have a possible stuck thermostat, and no heat, or your blower isn't blowing the heat thru the right vents, or the blower doesn't blow at all?
Would love to help, it's too damn cold!! (Even though we went from the teens last week, to 73 today. I actually rode my Harley all day yesterday with just a jacket. That's St. Louis weather for ya!!)
#149 of 371 Re: Heater only works sometimes????? [eriklane]
Jan 07, 2008 (7:11 pm)
you could take off the air filter housing,it should pop right off then you can look down at the plunger and see if it moves in or out.i took a long screw driver and kind of pulled up on the metal linkage on the top of it.if it moves up when you pull up on it you should replace it, also check the vacuum line that connects with the valve,.you should have someone start the van while you watch the top of the plunger with a flash light.if it is moving in and out when you turn the heat on and off it is working properly. as for the core,just unhook the 2 hoses and hold a garden hose to the core tube,top or bottom first,it doesn't make a difference.the water should flow through and back out the other tube at a good flow.if it piddles out or don't come out at all then its plugged.i didn't know much about these vans until i bought one.i had no heat and high speed on the fan.i asked my buddy who is a mechanic,he helped me trouble shoot the system.now i have heat on all speeds I also had the airflow mixture door stuck open so i was always sucking cold outside air in through the core so it wouldn't get hot just slightly warm.feel free to ask me anymore questions,i don't mind,its how i got my info.