Weak defrost

Wiring, lights, heater controls, anything electrical..
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davie

Weak defrost

Post by davie »

The motor sounds strong, the ducts are clear and the vents all operational but not a strong flow of air coming out of the vents. Does anyone have an upgrade for this system? A clear windshield and warm feet would be extra nice!! '66 W-200.

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oneowner71
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Post by oneowner71 »

did you check the air intake for the system?? If I remember right, the intake is in the cowl area on the passenger side, which last time I checked mine was about 4 inches deep in oak leaves. Helps with rust and airflow in all kinds of good ways...
Thanks, Clint
1971 D-100, 318 3-spd
1970 Dude, 383 / A727
1974 Challenger, 383/A727 (451 5-speed, someday)
1971 Plymouth Satellite,
2002 Dodge Ram 1500 Quadcab

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nfury8
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Post by nfury8 »

Does the 66 use vacuum control push buttons like the 71? If so, do the buttons feel solid, when one is pushed do the others all come back out to the correct position?

If the vacuum operated switch box is cracked it will not operate the doors correctly and air will not be completely routed. I had this same problem with a 69 Fury, which happens to use the exact same switch box as the 71 D-100. Replaced it and the heat/AC worked awesome! I am in the process of putting a new one in my truck right now.

shearingmatt
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Post by shearingmatt »

My 66 D-100 doesn't have vacume controlls. You reach underneath the dash to push a lever to turn it from heater to defroster.

The stock system on mine puts out a lot of heat if not as much air as some modern systems (well, until the heater core leaked and shorted something out, I need to tear it apart). If its the big black box type heater (like mine) there should be a little door on the far right side of it. Make sure that is open, that'll be the air intake when the vents are closed. Reach inside and to the left. You should be able to feel the heater core. Make sure there aren't any leaves or anything blocking the airflow. If you can't get in there very well from there, there should be a sheet metal screw on the front of the buttom. If you run your hand down the front of the big black box that has the heater core inside, you should feel it about an inch from the front. Once that is out the front will come off it will be easy to make sure that the heater core is clear of leaves and stuff.

Hope this helps.

Matt
66 D-100 long bed swept
Shearingmatt@yahoo.com

davie

weak defrost

Post by davie »

All manual on the '66, no fancy vacume here!! The blocked cowl intake is an excellent idea! I will check it out, but doesn't it also take in air from the cab?

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Seabee
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Post by Seabee »

something else that can happen over the years; dust accumulates in the vanes of the "squirrell cage" fan blades and renders them little more than paddles.

Davie

weak defrost

Post by Davie »

Dang, you guys are good! I am just going to disassemble the whole fan, cowl and heater box and see what's up and I'll let you know. Thanks for all the ideas!

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wideblock
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Post by wideblock »

try what matt suggested with opening the door on the lower right corner of the heater box, this recirculates the inside warm air and gives you better heat. cleaning the squirrel cage will do more good then you could imagine. but one thing you might want to do, this killed my 66's defrost. check where the vents mount ot the dash, mine had one tab broken on each vent and had allowed the vent to rotate where only a portion of the vent was actually shooting air out. my dash was real warm, but it didnt do much good for the windshield. you also need to make sure that the door for defrost closes all the way, this system doesnt allow for heat and defrost at the same time. so if you got warm feet, while its in defrost, your door on the inside aint shut all the way, and no matter what you do you wont have good air flow to the windshield. :Thumbsup

one last suggestion, oil the cables. this is done real easy on a 66 since they are wrapped with coiled steel as a housing. just soak the out side with penetrating oil, in a matter of minutes they will move nice and easy. they might not be moving far enough to open and close the doors the way they should.
Trey

1965 CSS Utiline.


ex trucks:
70 D100
66 d100
66 d100
67 d100
69 d100
69 d200 crew cab
65 crew cab
66 d100
66 d100


"i don't know it all, but i know enough to be dangerous"

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wideblock
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Post by wideblock »

i just got back from a drive into town and the thought hit me, wonder if this guys making the same mistake i did in my 66. pardon me for saying this, im not assuming your incompitent, but this is a mistake i made, so i figured it was worth at least mentioning. to work the heater, you pull the heater knob out, and flip on the switch for the blower, simple enough. heres where i screwed up, to work the defrost, you ADD the defrost being pulled out to the heater staying pulled out, you do not close the heater and pull the defrost knob. the heater cable opens the heater box to let heat into the cab, the defrost cable simply reroutes the air from the floor to the dash. if both knobs are not pulled out, then the defrost will only get the air blown around the closed heater door. i spent 2 months wiping the windshield with a rag on the way to work because of this "lack of knowledge". no assumptions are being made here to anyones intellegence except my own. it is possible that im the only moron that didnt figure this out the first time they used the darn heater, but i doubt it. :Thumbsup in any case, let us know what you do to solve your problem. it could be a big help to someone else with the same probs.
Trey

1965 CSS Utiline.


ex trucks:
70 D100
66 d100
66 d100
67 d100
69 d100
69 d200 crew cab
65 crew cab
66 d100
66 d100


"i don't know it all, but i know enough to be dangerous"

davie

weak defrost

Post by davie »

Trey, thanks for thr tips! Since I have no "owners manual" to describe operation, I appriciate your input! I admit that I have fiddled around with the push-pull knobs a bit looking for the right combo without actually LOOKING under the dash to see what was actually happening.

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wideblock
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Post by wideblock »

glad to hear im not the only one who didnt know how to work the dang thing!! LOL!! :dance :clap
Trey

1965 CSS Utiline.


ex trucks:
70 D100
66 d100
66 d100
67 d100
69 d100
69 d200 crew cab
65 crew cab
66 d100
66 d100


"i don't know it all, but i know enough to be dangerous"

davie

weak defrost

Post by davie »

OK, cage cleaned, al debri removed from heater box (not much there) but when I removed the cowl vent - man, what a pile of stuff was in there! Cleaned and flushed the cowl, lubed the wiper linkage, put it all togeather and it blows alot better now. Thanks all!

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wideblock
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Post by wideblock »

on the front of the heater box, far right side youll find a little door that open with a quarter turn of the latch. after the truck starts to get warm, id open the door on mine, you will get a lot hotter air sucking from the cab then from the cowl area. :Thumbsup
Trey

1965 CSS Utiline.


ex trucks:
70 D100
66 d100
66 d100
67 d100
69 d100
69 d200 crew cab
65 crew cab
66 d100
66 d100


"i don't know it all, but i know enough to be dangerous"

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