Cant open the heater all the way on 76 J10

[candymancan]

So on my J10. There is 3 button. Off. Heat and defrost.

If i hit defrost it clicks. But i dont really feel air coming out the dash up top. If i hit heat. Defrost pop out but the heat button doesnt click. Just pushes up and back out. But i do see the cob webs moving at the trabs hub. So i guess air is moving

The slider for cool and hot also seems stuck. Itll go to cool and sorta half way to mild. But it stops any further. When i check the heater box and try to move it manually it still stops. Feels like the flap is hitting something if i try to pull it any further

I can move it back and forth only like 1 inch. Any ideas on these subjects. Why isnt the heat button holding or clicking like off and defrost do.

I noticed those buttons when i had the cluster out. Were a giant vacuum line mess. There is a vacuum line going to a vall behind the carb thats broken. And i have it disconnected at thr intake so there is no vacuum leak. Is this line what conttols the heater ?

Also looks like a wire is cut there where that one line meets at the fire wall. By the brake booater

[letank]

So on my J10. There is 3 button. Off. Heat and defrost.

If i hit defrost it clicks. But i dont really feel air coming out the dash up top. If i hit heat. Defrost pop out but the heat button doesnt click. Just pushes up and back out. But i do see the cob webs moving at the trabs hub. So i guess air is moving

The slider for cool and hot also seems stuck. Itll go to cool and sorta half way to mild. But it stops any further. When i check the heater box and try to move it manually it still stops. Feels like the flap is hitting something if i try to pull it any further

I can move it back and forth only like 1 inch. Any ideas on these subjects. Why isnt the heat button holding or clicking like off and defrost do.

I noticed those buttons when i had the cluster out. Were a giant vacuum line mess. There is a vacuum line going to a vall behind the carb thats broken. And i have it disconnected at thr intake so there is no vacuum leak. Is this line what conttols the heater ?

Also looks like a wire is cut there where that one line meets at the fire wall. By the brake booater

as for the lever not moving, the heater box might be full of leaves so the flapper cannot compress any more compost! I rechecked mine and the lever on the heater box has a range of 90 degrees or about from closed to fully opened.

for the clicking... the lever could be slightly worn... or abused and the retainer tab does not catch on the bar of the control... usually the middle spring (pict) pops out but then any of the levers are not holding in the selected position

HeaterControlSpring.png

Cannot find a pict of the tabs, but this is a good start

[devildog80]

My heat control was a bit stiff in my '84 GW (after sitting 18 yrs), and a little 3 in 1 oil loosened it up so the buttons would function correctly, as the switch does not wear much on how it is built.
Check your little vac lines and be sure they are good, and pull your fan motor to clean out the plenum. Lots of older rigs do get critters building homes inside these when they sit for some time.
One of the first things you need to do, is get the vac line re-attached off the ball vac reservoir under the hood, and be sure to get some lube inside the heat select cable. Just a wire inside the jacket, but gets some rust inside from the metal wire over time.

Here is what my '84 GW looked like when I took the cluster out.

20221112_134849 by Scott Weckerly, on Flickr

20221112_133722 by Scott Weckerly, on Flickr

I used a scrap piece of stiff wire to hold the vac lines in correct position, when I pulled the cluster, so I knew what position they went back on the vac switch.

20221218_115139 by Scott Weckerly, on Flickr

[tgreese]

Using a Sharpie, you have a big drawing surface on the plastic bezel. Last Time I did this, I drew a picture of the valve and labeled the colors on this bezel. Good as a permanent reference.

The TSM has a diagram that shows what each vacuum motor does. It also shows where the cable connects. If not connected now, that should be plenty for how to connect. It's a switch - you can characterize it with your Mity Vac or simply blowing through it.