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73-87 Chevy _ GMC Trucks => Electrical => Topic started by: MEXICANKAMIKAZE on March 03, 2016, 01:51:49 am

Title: heater fan
Post by: MEXICANKAMIKAZE on March 03, 2016, 01:51:49 am
whenever i put my key in and turn it the fan comes on even when set to off. is that supposed to happen? or is there some wiring gone wrong somewhere
Title: Re: heater fan
Post by: blazer74 on March 03, 2016, 02:19:27 am
Normal for constant ventilation.
Title: Re: heater fan
Post by: FlatBlack77 on March 03, 2016, 07:24:50 am
it helps keep moisture out of the system
Title: Re: heater fan
Post by: bd on March 03, 2016, 09:12:11 pm
Quote from: blazer74 on March 03, 2016, 02:19:27 am
Normal for constant ventilation.

Quote from: FlatBlack77 on March 03, 2016, 07:24:50 am
it helps keep moisture out of the system

These ^^^^^

The constant flow of air helps to dry the ducts and prevent the growth of mold.
Title: heater fan
Post by: philo_beddoe on March 03, 2016, 09:48:37 pm
This pic is right from the 1977 owners manual. I have always wondered that too... (Yes, always on)
(http://uploads.tapatalk-cdn.com/20160304/2dcda7f0a933bfe578eaec89b43d0448.jpg)
Title: Re: heater fan
Post by: MEXICANKAMIKAZE on March 05, 2016, 04:55:08 pm
Yea i always wondered nice to know its not more faulty wiring
Title: Re: heater fan
Post by: philo_beddoe on March 06, 2016, 02:27:19 pm
They still should have given us the option to turn it off completely though.  Imo.
Title: Re: heater fan
Post by: gunrac on March 06, 2016, 07:15:28 pm
Quote from: philo_beddoe on March 06, 2016, 02:27:19 pm
They still should have given us the option to turn it off completely though.  Imo.

Just unplug it. I have at times thru the summer months.....
Title: Re: heater fan
Post by: philo_beddoe on March 06, 2016, 08:35:14 pm
Wheres the plug for it?
Title: Re: heater fan
Post by: gunrac on March 06, 2016, 09:18:34 pm
Quote from: philo_beddoe on March 06, 2016, 08:35:14 pm
Wheres the plug for it?

On the fan motor itself. Raise the hood, look toward passenger seat, mounted on the firewall.
Title: Re: heater fan
Post by: philo_beddoe on March 06, 2016, 09:59:06 pm
Oh yeah, thats right....duh. Drew a blank for a sec. thats all. For the record i knew where that was.  Or could just pull the fuse.
Title: Re: heater fan
Post by: philo_beddoe on March 31, 2016, 11:06:19 pm
Quote from: gunrac on March 06, 2016, 07:15:28 pm
Quote from: philo_beddoe on March 06, 2016, 02:27:19 pm
They still should have given us the option to turn it off completely though.  Imo.

Just unplug it. I have at times thru the summer months.....
For the record, i have been told by a reputable source not to unplug, air flow going through keeps fresh dry air moving and drives out moisture in the system. Just sayin...
Title: Re: heater fan
Post by: bd on April 01, 2016, 12:05:08 am
Quote from: philo_beddoe on March 31, 2016, 11:06:19 pm
For the record, i have been told by a reputable source not to unplug, air flow going through keeps fresh dry air moving and drives out moisture in the system. Just sayin...

This is a true statement.  The constant air circulation inhibits the formation of mold and odor.
Title: Re: heater fan
Post by: VileZambonie on April 01, 2016, 05:28:33 pm
Allowing mouse turds, moisture, pollen, dirt, etc to sit stagnant turning into crap moldy mildew and then blasting it in your face and into your lungs.... yeah, let's keep the air moving. They got it right in theory & they could have made it quieter but quite frankly who doesn't love the little growl from the blolwer motor for nostalgia when they turn the key on?
Title: Re: heater fan
Post by: philo_beddoe on April 01, 2016, 10:04:18 pm
Well stated! I hate mice, especially when they go number 2!
.....
Title: Re: heater fan
Post by: FlatBlack77 on April 02, 2016, 06:59:41 am
plus if you unplug it over summer and get caught in a rainstorm and you need to defog, you are in trouble lol
Title: heater fan
Post by: philo_beddoe on April 06, 2016, 10:00:33 am
Since this is a heater fan thread, although mentioned elsewhere, my truck is like a steam bath or like a hot steamy shower when i turn on the defrost on a cold day after warm up, kind of started all of a sudden. Windows fog up heavy on the inside. Totally clueless. Is moistere getting in somewhere, there is no smell whatsoever.
Title: Re: heater fan
Post by: AZ87V10 on April 06, 2016, 01:03:33 pm
What's the weather look like there? How cold is it? Humidity level? You're letting your engine warm up first before you turn your HVAC system on? If that's the case, it sounds like you're blasting air that is warmer and more humid onto the windshield than the surrounding ambient air. It's naturally going to condense when that happens. As long as there's no evidence of coolant in that fog on your windows then you're probably fine. Maybe wait for a warmer and dryer day and see if it does the same thing?
Title: Re: heater fan
Post by: Irish_Alley on April 06, 2016, 01:54:05 pm
have you checked the coolant level? i know you said it doesnt smell like it but there might be a chance
Title: Re: heater fan
Post by: AZ87V10 on April 06, 2016, 02:11:57 pm
Well, it's a pretty unmistakable smell when a heater core starts to fail. When the one went out in my Dodge last year, it stunk up the whole cab! Plus, the windows would fog over and you could see the oily residue of the coolant in it. I also had the signature steam coming from the HVAC vents! It looked like smoke but was evaporated coolant. I had it replaced and I still get the occasional smell of coolant whenever I run the heater.
Check the obvious things first like Tim suggested and go from there. It sounds like you might just have moisture build up in your ductwork. You said it's been cold there, the air in the ducts is warmer than the surrounding air and it's condensing like I already said. That seems the most logical culprit if your heater core is fine.
Title: Re: heater fan
Post by: philo_beddoe on April 06, 2016, 08:10:09 pm
I'll keep a close eye on those things you mentioned.  It is unseasonably cold up here in MA.
Title: Re: heater fan
Post by: philo_beddoe on April 07, 2016, 06:18:33 pm
Warm and heavy rain all day. Nonetheless, it wasnt too bad. I think for the short time i had it unpluged, moisture built up in there.