Cab heat

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Monk
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Cab heat

Post by Monk »

Well, I'm sure most should not have THIS issue, but....,, I case one does,,...

I noticed on longer trips , that my heat sucks big time, sometimes it goes cool air blowing (I guess room temp) then will go just Luke warm,...(can go up and down temp wise for air blowing)

I've changed threw the years rad / water valve / heater core / t-stat / everything lol, I could think of...

And still temps in cab fluctuated ,

Soooo only other thing is thought was my blend door actuator, I figure was moves by itself...

I removed the plug to it and always was "Luke warm"

Then week ago "outta boredom " I took the actuator off, WELL ....... I found out the hard way my "index" was off,...and now she can blow HOT AS HELL..... For Hwy driving,.. It gets hot, now not saying it's the best car heat, but Super good... As the fresh air door is closed fully...and for heat it was hot!!!

Just putting it out there in case your "Luke warm " temps
96 HMC4

Optimizer N/A

Super Swamper IROKS 39.5x13.5x 16.5
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whitehumh2
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Re: Cab heat

Post by whitehumh2 »

You should also consider blocking the radiator in order to reduce cooling the 32liters of coolant as you drive! That helps a lot as well!
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Skenth
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Location: Milton, ontario

Re: Cab heat

Post by Skenth »

Monk

Where is the actuator plug? I'd like to give it a try. Mine fluctuates from cold to Luke warm and sometimes warm.

Well, I'm sure most should not have THIS issue, but....,, I case one does,,...

I noticed on longer trips , that my heat sucks big time, sometimes it goes cool air blowing (I guess room temp) then will go just Luke warm,...(can go up and down temp wise for air blowing)

I've changed threw the years rad / water valve / heater core / t-stat / everything lol, I could think of...

And still temps in cab fluctuated ,

Soooo only other thing is thought was my blend door actuator, I figure was moves by itself...

I removed the plug to it and always was "Luke warm"

Then week ago "outta boredom " I took the actuator off, WELL ....... I found out the hard way my "index" was off,...and now she can blow HOT AS HELL..... For Hwy driving,.. It gets hot, now not saying it's the best car heat, but Super good... As the fresh air door is closed fully...and for heat it was hot!!!

Just putting it out there in case your "Luke warm " temps
Sonny Kenth

96 Hummer H1 4 dr Hardtop w slantback
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Monk
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Joined: Mon Oct 01, 2012 10:36 am
Location: Ontario

Re: Cab heat

Post by Monk »

Ok, passenger side, sit in your seat lol, and >>>>

1) remove the bottom foot cover thing

2) remove the cash pad

These are simple, but first time might take a few extra secs as once you see all the screws goes quick.

3) you then can then see and touch the motor, unplug that power harness to motor and leave hang

4) remove the 3 small nuts that hold that black motor (easy to reach) , I THINK 10mm socket worked

5) motor then can be pulled / slide off that shaft that controls the blend door


I found some pics so you can see about where it sits and also what the motor looks like


Yes, I used to be driving on the Hwy and temps (while trucks at operating temps) it would come out Luke warm , then

Go cool for a while, and honestly during our winters , lol we want hot all the time, heehe
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Last edited by Monk on Fri Dec 30, 2016 6:48 pm, edited 1 time in total.
96 HMC4

Optimizer N/A

Super Swamper IROKS 39.5x13.5x 16.5
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Monk
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Location: Ontario

Re: Cab heat

Post by Monk »

Basically it sits in the very side of your hvac unit, and super easy job, and can be a 10-15 min job , lol, long as nothing screws up....hehe

And when reassembling, just be gentle and dot over tighten nothing,


I took (for now) my blend motor off, (and put in glove box) .... Now the door is fully "naturally" spring closed (when the motors off)and at 100% pure heat, or lol what ever we can sqeak out of our hummers....

I notice now on hwy, it can get hot air now.....

But, if I'm idling in a parking lot, she's not the hottest air, but zero cool temps like before,

I'll replace my motor in spring, I think my motor was not closing the blend door fully which keep heat not the best....


Also I should note, if you want to try easy, you can just unplug the motor and the blend door should be closed, mine didn't close all the way so I had to remove my motor and I could hear it shut,

Hell, you can turn you shaft by hand (after the motors off)if ya want to hear it shut
Last edited by Monk on Fri Dec 30, 2016 6:57 pm, edited 1 time in total.
96 HMC4

Optimizer N/A

Super Swamper IROKS 39.5x13.5x 16.5
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Skenth
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Location: Milton, ontario

Re: Cab heat

Post by Skenth »

Thanks Monk for the info & pic. I took the easy way as you suggested... I managed to locate the unit and I've unplugged the plug (looked like a computer hard drive plug with small pins adaptor). Additionally I've also blocked off the hood grill radiator (worked great last year). Now it's time to test it out!


Basically it sits in the very side of your hvac unit, and super easy job, and can be a 10-15 min job , lol, long as nothing screws up....hehe

And when reassembling, just be gentle and dot over tighten nothing,


I took (for now) my blend motor off, (and put in glove box) .... Now the door is fully "naturally" spring closed (when the motors off)and at 100% pure heat, or lol what ever we can sqeak out of our hummers....

I notice now on hwy, it can get hot air now.....

But, if I'm idling in a parking lot, she's not the hottest air, but zero cool temps like before,

I'll replace my motor in spring, I think my motor was not closing the blend door fully which keep heat not the best....


Also I should note, if you want to try easy, you can just unplug the motor and the blend door should be closed, mine didn't close all the way so I had to remove my motor and I could hear it shut,

Hell, you can turn you shaft by hand (after the motors off)if ya want to hear it shut
Last edited by Skenth on Tue Jan 10, 2017 2:38 pm, edited 1 time in total.
Sonny Kenth

96 Hummer H1 4 dr Hardtop w slantback
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Monk
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Location: Ontario

Re: Cab heat

Post by Monk »

Exactly , I think it had like 5-6 pins, but ya, that's what did at first and I'd BET your is position proper,

Yes , as Polar Bear mentioned , the covering the hood make a nice difference ,...


My issue was I have a dog that I drive everywhere with me, he lays at the middle tunnel at the back, soooo I can't use back heater or (Even if I closed vents) still hot air blowing at him...

During our last cold spell, I removed the 2 back centre middle louvers, and then pulled up that centre back heater plastics cover,..

Put 2 piece of plastic over the two holes, then duct tape over the two holes from the Louvre spot,


then replaced the cover and will keep my vents in the garage (they won't fit back for now, to deep) BUT now its air blocked 100%, zero air come now from the back upper vent area, and now I can keep the rear heater on, and it will blow on my right arm, and down to the rear floors and the dog stays cool and lol I can have extra heat,...
Last edited by Monk on Tue Jan 10, 2017 4:00 pm, edited 1 time in total.
96 HMC4

Optimizer N/A

Super Swamper IROKS 39.5x13.5x 16.5
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Skenth
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Posts: 185
Joined: Tue Jun 04, 2013 10:59 am
Location: Milton, ontario

Re: Cab heat

Post by Skenth »

Unplugging didn't make much of a difference unfortunately. It still cycles back to cool and then warm again...should

I plug it back in so it's all back to stock


Just as an aside, I too have non heated windshield....do u notice that the defrost does a pretty good job for passenger side windshield but not so much for driver side. I'm thinking maybe something is stuck in my front driver side defrost vent by the windshield. Or is it just poor design?


Also any suggestions for fog clearing??
Sonny Kenth

96 Hummer H1 4 dr Hardtop w slantback
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Monk
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Joined: Mon Oct 01, 2012 10:36 am
Location: Ontario

Re: Cab heat

Post by Monk »

Wait, before ya plug it back in hit the Hwy, and see if it's hotter then before? I didn't notice any difference while idling


Also I use "rainX" from Canadian tire you wipe on the inside of the window, I find fogs worst on days like this, rainy....


I'm gonna check mine, not sure on the air pressure per side...

I did however see a video of someone taking a damper piece out of the vents at the front, to increase air flow at windshield...

I'll look for it when I get back,
96 HMC4

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Super Swamper IROKS 39.5x13.5x 16.5
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Boeing Jet
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Re: Cab heat

Post by Boeing Jet »

Another thing I noticed is that just near that motor is another flap which is hooked to the vacuum system. What ever I sent my controls to that flap doesn't open. As an experiment I opened it and noticed more air coming though the vent then when it's closed so now I have it in the open position and now have more air through the windshield or feet or face vents
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