2001 Chevy Astro no heat

KCFCHI

MEMBER
2001 CHEVROLET ASTRO
6 CYL
2WD
AUTOMATIC
84,000 MILES

When I turn the knob to red to make heat the air just blows cool. The water in the radiator is at top. I turned the heat on the other day and it started to blow warm but shortly after turned cool again. Is there something electrical involved? Winter is coming and I'm getting concerned. Ps: I just purchased and took possession a week ago.

3 Replies

HMAC300

MECHANIC
48,601 POSTS

Theere is an air temperature acutator on the passenger side above the heater, you'll probably have to feel around for it to find it. There is also a coolant bypass valve behind the drier under the hood, that is the big silver thing on pass side. Check to see if the by pass valve is stuck or not getting any juice. Then go to the temp door.

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Tuesday, August 31st, 2010 AT 7:54 PM

KCFCHI

MEMBER
5 POSTS

Thanks for the new info. I also have new info that I think leads to the bypass valve. While driving (on 2 different occations) I actually got heat into the cab, however for short periods only. Also I can hear the temp door opening and closing, which seems to eliminate that. I can clearly see the junction of hoses behind the drier on the bypass valve. Now my 64k $? Is how is that manipulated. I don't readily see electrical wire to it or a manual switch. I havent begun to really get down in there so i'm possibly missing something. Before I do I want to ask you if you know of a manual manipulation or what was meant in your response by "see if its getting 'juice'"
thanx, I know I am getting close to the end now

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Wednesday, September 1st, 2010 AT 3:25 PM

HMAC300

MECHANIC
48,601 POSTS

"juice" mean power that's all. When I looked to find the water valve it showed electricty going to it to operate it. Before you go through contortions though, see if there is a relay for it. It should be plainly called out although I didn't see itin the wiring schematic. If you can find the wire, you will only need a test light to see if it is getting power or not. But it may be low voltage if it lights dim. But a volt meter is alot better.

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Wednesday, September 1st, 2010 AT 3:51 PM