72Cyan
Newbie
Posts: 18
Loc: Seattle
Reg: 12-21-22
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01-05-23 05:40 PM - Post#2853231
On my 1972 C10 with factory a/c, the heater control on the dash is a bit finicky. My 72 GMC from years ago had the same issue. When you slide the heat lever over to the far right/max it doesn't like staying there, it usually wants to slide back about 1/2 an inch or more.
First, I would think it has to do with the cable not being tight enough, but I also know the lever that attaches to the cable on the backside of the controller, behind the dash, is pushed tight up against all the hoses underneath the dash. This makes me think perhaps the issue is the lever hitting one of the hoses. But as this has happened with 2 of 2 of my own a/c equipped trucks I suspect its a common issue. Do others have the same issue, and has anyone figured out a solution?
Dan J. C.
Seattle, Washington
1972 Chevy C10 Cheyenne, SWB, 350/350, Hawaiian Blue/Blue
71,000 original miles (rebuilt at 65k)
3 owners, Garaged since new
Respray in 2010, new carpet and seat upholstery
Undercarriage all original |
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Tony1963
Frequent Contributor
Posts: 2056
Loc: Orlando Florida
Reg: 07-09-18
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01-06-23 01:12 PM - Post#2853248
In response to 72Cyan
I've had similar issues on GM vehicles with cable operated controls. Here's what I did.
You have to play with the adjustment of the cable until you effectively "center" the throw on the cable. In other words, adjust the cable so that the end of the throw is at the end of the door's movement. If the other end of the adjustment is now too short, adjust a little more to center the entire travel on the door to the slot on the heater control.
| People fear change because it threatens what they know, or what they claim to know. |
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72Cyan
Newbie
Posts: 18
Loc: Seattle
Reg: 12-21-22
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01-06-23 07:01 PM - Post#2853253
In response to Tony1963
thanks, I'm not fully understanding what you're saying beyond the adjustment of the cables. 
I've had similar issues on GM vehicles with cable operated controls. Here's what I did.
You have to play with the adjustment of the cable until you effectively "center" the throw on the cable. In other words, adjust the cable so that the end of the throw is at the end of the door's movement. If the other end of the adjustment is now too short, adjust a little more to center the entire travel on the door to the slot on the heater control.
Dan J. C.
Seattle, Washington
1972 Chevy C10 Cheyenne, SWB, 350/350, Hawaiian Blue/Blue
71,000 original miles (rebuilt at 65k)
3 owners, Garaged since new
Respray in 2010, new carpet and seat upholstery
Undercarriage all original |
|
69_BOWTIE
Senior Member
Posts: 1174
Loc: WYOMING,USA
Reg: 02-27-02
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01-07-23 09:31 AM - Post#2853259
In response to 72Cyan
Is your cable pinched ? Take it loose from both ends and see if it moves freely. I took 3n1 oil and lubed cables ,sounds like you don't have it adjusted right, when you have the end off check the travel distance of the door it dont take much movement to close or open the door. You have to find that sweet spot
2001 Silverado 4X4
2005 FXDWGI
69 CHEVY C-10 Short Step 327
63 IMPALA 2/DR HRDTOP 327 |
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72Cyan
Newbie
Posts: 18
Loc: Seattle
Reg: 12-21-22
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01-11-23 06:19 PM - Post#2853345
In response to 69_BOWTIE
thank you. but where exactly is the "other" end? :wink :
Is your cable pinched ? Take it loose from both ends and see if it moves freely. I took 3n1 oil and lubed cables ,sounds like you don't have it adjusted right, when you have the end off check the travel distance of the door it dont take much movement to close or open the door. You have to find that sweet spot
Dan J. C.
Seattle, Washington
1972 Chevy C10 Cheyenne, SWB, 350/350, Hawaiian Blue/Blue
71,000 original miles (rebuilt at 65k)
3 owners, Garaged since new
Respray in 2010, new carpet and seat upholstery
Undercarriage all original |
|
69_BOWTIE
Senior Member
Posts: 1174
Loc: WYOMING,USA
Reg: 02-27-02
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01-12-23 06:12 PM - Post#2853363
In response to 72Cyan
Its well worth the $ to have a service manual for these trucks. ITS up under dash , Do a google search, cant remember off the top of my nogin . and its to cold to go to the garage and look.
2001 Silverado 4X4
2005 FXDWGI
69 CHEVY C-10 Short Step 327
63 IMPALA 2/DR HRDTOP 327 |
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AngeloB
Newbie
Posts: 1
Reg: 08-14-22
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01-12-23 07:23 PM - Post#2853365
In response to 69_BOWTIE
You should find that cable and lever just above the floor defrost outlet on top of floor hump. Take the retaining clip off of the lever then remove the cable retaining screw. That will allow you to remove the cable to test the control arm and cable for freeplay movement. You can also check the damper door movement.
A lot of times the binding is due to that damper sticking in its housing as the factory grease has long since dried up.You can grease most of the friction points with a small brush but I usually remove that housing for cleaning and grease.
Angelo
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doubleE
Valued Contributor
Posts: 3929
Loc: Eagan MN
Reg: 06-02-03
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02-02-23 04:43 PM - Post#2854068
In response to AngeloB
I have a 72 C10 and have the same issues with the heater cables (no AC). I think with age these cables just get old and worn out and build up resistance. On other vehicles I've owned I would pull out the inner wire, clean it with steel wool. Also would soak the the outside jacket in diesel fuel for a couple days. After blowing them dry with some compressed air, I reinsert the core wire coated in lithium grease.
Now the problem with the 67-72 C10s is both ends have a loop making it impossible to remove the inner wire without cutting it making it useless.
Solution would be to buy a new set of cables which are available from several vendors.
Eric
| Proud owner of
My Blue 62
Impala SS |
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72Cyan
Newbie
Posts: 18
Loc: Seattle
Reg: 12-21-22
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02-09-23 08:17 PM - Post#2854318
In response to doubleE
Issue resolved. I pulled apart the entire bottom end of the interior heater a/c parts. First the flapper to divert air/heat between upper dash/defrost and the three dash vents was broken. I had to order a new box, then while those cables were detached, I lubricated all with WD-40 on both ends and manipulated all the levers/cables. Works just like new.
Dan J. C.
Seattle, Washington
1972 Chevy C10 Cheyenne, SWB, 350/350, Hawaiian Blue/Blue
71,000 original miles (rebuilt at 65k)
3 owners, Garaged since new
Respray in 2010, new carpet and seat upholstery
Undercarriage all original |
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