defrosters

[Brainchild]

OK I know these trucks aren't the best in the defroster area,but is there any better vents out there than the ones that came stock?
I changed the hoses,heater core and thermostat,might as well go the distance.

[passthebuck]

I hope i can help. I dont know of better defrosters, but to improve efficency of your current system, make sure that where the hoses enter/exit the heater box under the hood that they are well sealed. (I used hockey tape) Also, make very sure that the heatercore is sealed very well against the inside of the box to prevent the highpressure heated air from going around the core instead of through. With these mods & a new core I now have a serious heater that does just fine all the way down to -30C. & I'm happy to report that I no longer need the frost shields! (I keep them on to be retro though)

[Brainchild]

I did swap the core already,and I am going to pull the inside box out this week,and do some repairs,if it ever quits raining
It was only mid 30s today,and I had 2 large circles to look through most of the day.I can't even imagine what that's gonna be like in a serious cold spell with blowing snow.

Thanks for the help

[mrein3]

Originally Posted by Brainchild

I did swap the core already,and I am going to pull the inside box out this week,and do some repairs,if it ever quits raining
It was only mid 30s today,and I had 2 large circles to look through most of the day.I can't even imagine what that's gonna be like in a serious cold spell with blowing snow.

I'll guess it will be better if it is snowing and blowing.

If it is snowing and blowing the air is usually dry. When it is raining it is usually wet. It sounds like you had a lot of moisture in the cab.

In addition to keeping you cool in the summer air conditioning also dries the air out. The next time it is raining and you only have two circles to look through turn on your AC. If you don't have AC consider adding it.

[Brainchild]

The truck had AC,and someone changed the wiring harness,and heater box over to the non AC,why I have no idea.
Anywho,that's a lot more work than I intend to do this winter

SOooo back to the old school defrosters

It has rained every other friggin day for a month,and I am defroster challenged ATM.Snowing yesterday,I may have to pull the heater apart today.

[Brainchild]

It was a beautiful day here in the Ozarks today,so I pulled all the heater out of the truck,and cleaned,lubed,and insulated everything.Swapped out all the defroster hoses,ect.Put it all back together,and while i still don't have much flowing through the defrosters,it is nice and Hot.
The switch in the assembly isn't working either,I'll have to change that,and I just have a toggle on the fan right now.But at least it's warm in the truck now

[purple gas]

Just a thought,, CLEAN windows are easier to keep fog/frost free. Espicailly if you're a smoker.. keeping the inside of the glass clean means less tiny little particles for the moisture to condense on. also cracking a window just a tiny bit lets the air flow out of the cab, meaning less restriction on your blower. Just like Headers,, it's all about air flow.

[GMC Jim]

Blower motor for Standard DeLuxe Air System ( 13.5 volts; 6.25 max amps[cold], RPM - 2550 min./2950 max )

Blower motor for Four-Season Air conditioning system ( 12 volts; 16.5 max amps[cold], RPM 3700 Min )

The bpwer desinged for air conditioning is interchangeable and as per above specs; puts out a lot more air; increasing efficiency and very noticeable in defrost mode.

[Terry Peerson]

You might want to check your "Diverter" box. Make sure the flapper isn't broken. When I first got my '72, my flapper wouldn't move 'cause the rubber that connects it to the pivot rod had just rotted out. ALL of the air was coming out of the dash vents. It didn't matter where the heater controls were set. Replaced the "Box" and it worked like a new system!

TP

[71-longbed]

yep i second that ... i notice a huge bump in fan speed with i crack a vent window

[GreyHoundSteve]

I live in TX so i dont have any need for this product my my granny who lives in South Dakota uses this product that is intended for eye glasses and she snears it on her car windows and it keeps them from fogging. She said she bought this stuff at lenscrafters and has been using it for years and it works great.

[chickenwing]

I used a product by Rain-X called No-Fog in my old crappy no-heater or nothing else 75. I remember it working pretty good. It might get ya by a week or so till ya get em fixed.

[purple gas]

Now that I think of it, good old fashioned shaving cream works great to keep fog off of glass. I use Barbasol myself. Put a teeny tiny bit of it on the bathroom mirror wipe it on with a paper towel & the mirror doesn't fog up even after the hottest steamiest shower.(apply it before you steam up the room). haven't tried it in a truck but I bet it would work. & likely cheaper than the special stuff you'd buy. try it, you'll be amazed.

[toddtheodd]

Originally Posted by GMC Jim

Blower motor for Standard DeLuxe Air System ( 13.5 volts; 6.25 max amps[cold], RPM - 2550 min./2950 max )

Blower motor for Four-Season Air conditioning system ( 12 volts; 16.5 max amps[cold], RPM 3700 Min )

The bpwer desinged for air conditioning is interchangeable and as per above specs; puts out a lot more air; increasing efficiency and very noticeable in defrost mode.

And I can use this motor on my truck even though my truck is a non-a/c truck? Just a straight changeover?
Makes that big of a difference too?

[Brainchild]

Originally Posted by GMC Jim

Blower motor for Standard DeLuxe Air System ( 13.5 volts; 6.25 max amps[cold], RPM - 2550 min./2950 max )

Blower motor for Four-Season Air conditioning system ( 12 volts; 16.5 max amps[cold], RPM 3700 Min )

The bpwer desinged for air conditioning is interchangeable and as per above specs; puts out a lot more air; increasing efficiency and very noticeable in defrost mode.

Thanks Jim,that's a nice piece of info to hang on to I think I'll swap the motor before too long

As far as the box,I pulled cleaned and fixed all that stuff yesterday.It works much better now.It even warms the truck

[Hooter]

I just plain dont drive mine in the winter , I thought I was the only ony with a ****ty defroster in my truck, good to know im not the only one with this problem

[passthebuck]

i know this is an obvious-type question but what temp thermostat are you running there brainchild?

[Brainchild]

192 degree.It's plenty hot now that I took it all apart and cleaned it up,just not much airflow to the top,adn I have replaced the hoses to the defrosters as well

Hooter,I have never owned one of these trucks that had a great defroster,and I have owned several too.The little square outlet just doesn't work that well to clear the window,which is why I was hoping they had an aftermarket unit that was better than the stock ones.The faster rpm motor sounds like a good investment though

[GMC Jim]

Brainchild, a defective flapper door that directs air to the defroster vents is a common defect in these 30+ yrs old trucks....a quick check is to put the control levers in defrost position and feel for air coming from heater floor vent or any of the 3 dash mounted airconditiong vents...If so, then the flapper doors are defective or the cables from the control head are not adjuted properly....There is a flapper door located on the lower part of the heater assembly. This door directs air to floor outlets or the defroster outlets...adjust so that at end of cable travel; all the air is going to the defroster outlets and none to the floor outlet. Another door; termed the 'outlets' door directs the air to the dash outlets at one end of travel and the air to the floor outlet/defroster door at other end of travel.

In summary, when the control levers are in full defrost position; ther should be no air comimg from the floor outlet or the dash outlets.....
Of course , you will want to check that all air duct hoses are seated properly....

[Brainchild]

I'll give it a test today at work Jim,but it's not too bad right now.I took the girl to school a bit ago,and after sitting all night,and being 30 degrees outside the heater was warm,and the window clear by the time I drove 4 blocks to,and back from school.I'd say it was 15 minutes tops.
I drove it 20 miles a few days ago and like to froze to death,so it is way better