wraenking
1/2 ton status
went to go use the heat today, and i only have cold air blowing. where do i start?
CK5
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heat not blowing hot?
- Thread starter wraenking
- Start date
Esteban86K5
1/2 ton status
Start by checking that the hoses aren't kink or clogged. Then disconnect the top and bottom hose going into the heater core and run some water through it with a garden hose to make sure that there is flow. You may find that the heater core is clogged up from years of use. I hope for your sake it isn't that because they are a PITA to change. /forums/images/graemlins/doah.gif
good start there! Also check and make sure that your controls are actually moving the components that decide either hot air or vent air comes in.
wraenking
1/2 ton status
ok, i looked behind the glove box, and the the rod (arm) that controls the cold to hot lever works fine, the one that goes from , ac, vent, heat and so forth is barely moving.
any suggestions?
any suggestions?
BranndonC
3/4 ton status
thermostat not running hot enough? whats the motor usually run at?
wraenking
1/2 ton status
she runs at about 180
RustBuket
1/2 ton status
I'm pretty damn sure this isn't your problem but its funny:
I had enough antifreeze to go down to -40 Celcius but it went down to -50 Celcius for a few days (I live on the prairies of Canada ... /forums/images/graemlins/crazy.gif) so I just left it plugged in for the days that it was below but when I went to start it up, it blew snow!!! The heater core froze up!! /forums/images/graemlins/rotfl.gif I had to run it for about an hour to get it to thaw and blow hot again... lol..Blizzard inside the cab!! /forums/images/graemlins/peace.gif
I had enough antifreeze to go down to -40 Celcius but it went down to -50 Celcius for a few days (I live on the prairies of Canada ... /forums/images/graemlins/crazy.gif) so I just left it plugged in for the days that it was below but when I went to start it up, it blew snow!!! The heater core froze up!! /forums/images/graemlins/rotfl.gif I had to run it for about an hour to get it to thaw and blow hot again... lol..Blizzard inside the cab!! /forums/images/graemlins/peace.gif
Can Can
Pusher Man
Let's start here: When you switch from AC to floor to defrost can you hear a slight vaccuum hiss followed by a clunk under the dash somewhere?
wraenking
1/2 ton status
i hear a hiss for sure. dont know about a clunk.
should that lever by the glove box move a lot, cause its barely moving
should that lever by the glove box move a lot, cause its barely moving
Can Can
Pusher Man
I've gotta dig up an old post of mine that explains how all the vacuum-actuated shite under the dash works. I'm willing to bet that your hot/cold door isn't opening and letting warm air in from the heater box......
Does anybody have the post in question in their faves? It's from the 73-91 tech board.
Does anybody have the post in question in their faves? It's from the 73-91 tech board.
wraenking
1/2 ton status
def interseted in that post
sheel kill me if we go camping witho0ut heat /forums/images/graemlins/thumb.gif
sheel kill me if we go camping witho0ut heat /forums/images/graemlins/thumb.gif
The arm that opens that blend door is held with a plastic clip. When you go from heat to defrost that door closes and vice versa when going from defrost to heat.
Often the little plastic clip breaks and the arm moves but the door stays partially open. You end up with weak defrost and weak heat.
Does this sound familiar or do you get good airflow but it's cold?
If it's just blowing cold the first thing I'd do is check the coolant level. Too many times I've found out the coolant was low...
Rene
Often the little plastic clip breaks and the arm moves but the door stays partially open. You end up with weak defrost and weak heat.
Does this sound familiar or do you get good airflow but it's cold?
If it's just blowing cold the first thing I'd do is check the coolant level. Too many times I've found out the coolant was low...
Rene
wraenking
1/2 ton status
will check all tomorrow, and give an update. so who wants to fly in to swap in my ax;es lift and tires?
lol
lol
What the heck do ya need heat for? It's still like 95 degrees in the day time for goodness sake!!! /forums/images/graemlins/screwy.gif /forums/images/graemlins/histerical.gif
Rolled
1/2 ton status
[ QUOTE ]
What the heck do ya need heat for? It's still like 95 degrees in the day time for goodness sake!!! /forums/images/graemlins/screwy.gif /forums/images/graemlins/histerical.gif
[/ QUOTE ]
Too funny /forums/images/graemlins/histerical.gif I have not used a heater in years. In fact, I use the AC, just about, every day of the year in my cars/trucks /forums/images/graemlins/smile.gif
Another month and the weather will be perfect for the last of my Blazer projects. I can't wait /forums/images/graemlins/smile.gif Right now, it's still a bit too hot to get serious about anything outdoors...
What the heck do ya need heat for? It's still like 95 degrees in the day time for goodness sake!!! /forums/images/graemlins/screwy.gif /forums/images/graemlins/histerical.gif
[/ QUOTE ]
Too funny /forums/images/graemlins/histerical.gif I have not used a heater in years. In fact, I use the AC, just about, every day of the year in my cars/trucks /forums/images/graemlins/smile.gif
Another month and the weather will be perfect for the last of my Blazer projects. I can't wait /forums/images/graemlins/smile.gif Right now, it's still a bit too hot to get serious about anything outdoors...
R72K5
Banned
sounds like plugged heater core, or incorrect routing of core hoses, or stuck closed heater core hose inline valve- if so equipped,
if so equipped then remove it, i would anyways, but then youre in AZ so maybe it wouldnt be such a HOT idea
if no luck iwth any of the above then make sure the vacuum hose for heater controls is connected to intake vacuum source, trace it from heater box under hood to engine, its a small plastic black vacuum tube line, without it you will have no operation of the control panel for the vent boxes assembly and flappers and vacuum diapragms but youll still have blower though btu would be cold only most likely, IE outside air only and not through heater core box unit inside cab
if control panel position lever seems like it has very little or no resistance then the cable may have come off at one end or may have broken, but i have never seen either happen and i have had ALOT of gm trucks 67-87, and have disassembled ALOT of them too, never seen a cable break or come off, so,,.
if i had a digicam then i could take you soem pics of heater box and cables related stuff, as i have some 73-up boxes laying upstairs that are destined for scrap after i rmeove the heater cores for their copper.
if so equipped then remove it, i would anyways, but then youre in AZ so maybe it wouldnt be such a HOT idea
if no luck iwth any of the above then make sure the vacuum hose for heater controls is connected to intake vacuum source, trace it from heater box under hood to engine, its a small plastic black vacuum tube line, without it you will have no operation of the control panel for the vent boxes assembly and flappers and vacuum diapragms but youll still have blower though btu would be cold only most likely, IE outside air only and not through heater core box unit inside cab
if control panel position lever seems like it has very little or no resistance then the cable may have come off at one end or may have broken, but i have never seen either happen and i have had ALOT of gm trucks 67-87, and have disassembled ALOT of them too, never seen a cable break or come off, so,,.
if i had a digicam then i could take you soem pics of heater box and cables related stuff, as i have some 73-up boxes laying upstairs that are destined for scrap after i rmeove the heater cores for their copper.
