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73-87 Chevy _ GMC Trucks => Interior & Equipment => Heating, Ventilation & Air Conditioning (HVAC) => Topic started by: juancano on September 07, 2023, 08:48:58 pm

Title: Air blows sometimes, most times it doesn't
Post by: juancano on September 07, 2023, 08:48:58 pm

Hi; 1986 Silverado. This truck had AC but at some point it was removed.

If I try to use the Vent to blow air, nothing happens 75% of the time. Then sometimes after it's been "on" for a bit, it starts up and I get air blowing.

I can't seem to find a pattern. I don't understand enough of how it works.

Any ideas? Thank you.

Title: Re: Air blows sometimes, most times it doesn't
Post by: Mike81K10 on September 07, 2023, 09:11:25 pm

I had a nest in my unit by the doors that prevented the doors from operating properly. I believe others have experienced the same. Pull the unit off and check inside would be one suggestion.

Your fan could also be going bad or you might have a bad wire connection. Check connector to fan, clean if needed.

Title: Re: Air blows sometimes, most times it doesn't
Post by: juancano on September 08, 2023, 08:20:35 am

I'll do that; where is the fan in this truck? Under the dash or under the hood? Wondering if it's part of the old AC leftover parts. Thanks

Title: Re: Air blows sometimes, most times it doesn't
Post by: Mike81K10 on September 08, 2023, 01:33:41 pm

Firewall Passenger side, under the hood.

Title: Re: Air blows sometimes, most times it doesn't
Post by: juancano on January 24, 2025, 01:59:32 pm

I cleaned the old blower fan a while back, and this week I put a brand new AC blower from a 1994 Truck. Same result.

I am thinking next steps is checking the heater box and see if the flaps open correctly. My heat also doesn't seem to work. Heater core replacement then.

Title: Re: Air blows sometimes, most times it doesn't
Post by: bd on January 24, 2025, 02:20:43 pm

Does the blower motor turn on like it should but no air flows from the vents, or is the blower motor dead?