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wil84911

Stuck Heat Lever

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Top lever pushed to the right (heat) and won't move back left. Unsuccessfully tried removing that panel. Anyone encountered this or could provide a solution? Many Thanks!

IMG_8600.JPG

 

 

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I think that you need to remove the console and the whole assembly to get behind the panel.  It's probably shown in the FSM.  Might be in the site's Technical area also.

I had a similar problem.  The lever pushes and pulls on a stiff cable.  If somebody gets aggressive on the push, the cable bends and shortens up.  Then it acts like a spring and won't allow the knob to come back.  I straightened mine out and had it working for a while but eventually I replaced it with a piece of piano wire.

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Look on the driver's side, to the right of the gas pedal.  One goes all the way to the fire wall, another to the side of the radio mount.  Take them loose and try working it.  Seems like the top one is the one that goes to the firewall?  The middle is to the heater core valve on the passenger's side.  The bottom is the one that opens those doors behind the radio, or maybe it's the top one???  Anyway I'd bet it's the one to those doors/flaps that you need to free up. 

That panel is a huge pain to remove.  Very fragile to.  Good luck.

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As noted by others, you have a bit of a 'task' ahead of you in order to fix the stuck lever.

The centre (tunnel) console has to come out first.  Be careful not to break the plastic.  You'll need to detach the choke lever assembly from the console.

Remove the radio control knobs and fastener nuts, then remove the radio faceplate.

Remove the knobs from the heat/vent control levers.

Remove the Blower fan speed control knob and the retaining nut behind it.

Remove the Map light faceplate and then lever the map light housing out of the heater fascia plate.  If possible, pop the wiring connectors free and remove the map light altogether.

At this point, you should have an assemblage of parts that looks like this (these are from a Series 1 car, so your parts may look a bit different)...

x100_4071.jpg

Now disconnect the four heat/vent control cables where they connect to the Heater assembly.  You'll find three of the cable connections on the pssgr side of the Heater assy and the fourth on the left side.  The securing clip for the cable that connects to the heater control valve (lower right side of the Heater assy) is often corroded.  It will probably help to apply some penetrating oil first and let it soak in for a day before you try to loosen the screw.

Remove the four screws that secure the Heater fascia plate to the Dash frame.

At this point, the Heater fascia plate is ready to come out.  As you pull it away from the Dash, it will come away complete with the Heat/Vent control lever assy and the four control cables. The cables are curved and somewhat stiff, so you'll need to tug a bit to pull them free.  The radio and the Fan Blower speed control knob will get left behind.  The lower part of the Heater fascia plate is like a ring and it can break at the corner(s) if you pull on the fascia plate unevenly or too enthusiastically.  Here's what you'll be looking at (sort of)...

x100_4195.jpg

 

Experienced Z owners will see that my control lever assembly had experienced not just a bent cable (not visible in the photo above) also a mechanical failure of the topmost linkage (a guide pin had snapped out of the lever frame, allowing the top upper lever plates to separate. 

An intact lever assy looks like this (note how the slots in the two top link plates both fit over a common 'peg')...

x100_4655.jpg

 

Here's what a bent control cable looks like this.  On my car, it was the bottom lever and cable (goes to the heat control valve) that had problems.  The cable was bent into a full J-hook shape.  In the photo, the lever asy has been turned upside down, so you're looking at the bottom...

70Z Heater Control Lever Assy 4.jpg

 

You won't be able to unbend a bent control cable.  Easiest is to buy new ones (Z-Car Depot has them, maybe others do too).  Or you can do what Zed Head and I  did, which is to buy a roll of tempered-steel 'music' wire and form your own.  Not easy, but not impossible either.  The Series 1 system used 1.0mm wire.  Later versions used 1.2mm wire.   The ID/OD of the plastic cable sheathing is the same for both versions, so you can use 1.2mm cable inside the Series 1 or Series 2 sheathing.

Make sure you find out why your control cable bent and fix that problem too.  Otherwise, your new cable will probably bend just like the old one did.  Unfortunately, the top control lever operates two inner air control flaps that are buried inside the Heater assy.   It's not likely that they've jammed just because the pivot points got a bit rusty.  Instead, it seems more probable that the one of the padded vinyl covers used on the internal control flaps has come unglued from the metal flap plate (common problem) and is preventing the flap from closing fully...

100_4276.jpg 

 

To the driver (or passenger), this would have felt like the control lever wasn't moving all the way to the right or left in its slot, so they would have started tugging on it to try to get the lever to go to the full 'OFF' or (more likely) 'HEAT position'.  If I'm right (and I hope for your sake that I'm not) you're going to have to drain the engine cooling system, disconnect the heater hoses, pull the Heater assy out of the car, and then pretty much fully disassemble it.  Big job. :ermm:

 

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That's quite a write-up.  I was thinking of your other article when I mentioned that something might be in the Technical area.  

 

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Thank you so much for the replies. I will certainly report back once I get somewhere with this. Obviously with the colder northeast weather up ahead I really don't mind some permanent heat. 

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I went a step further after removing the entire assembly. Each control cable has an E clip at the anchor/swivel point. These are easily removed with a jewelers screwdriver. Be careful they have a spring loaded effect when they release. Suggest disassembly with a large beach towel to avoid things bouncing away. Do one cable at a time so you don't confuse reassembly. I then straightened one end just enough to get the insulation to move over it without damage. Then smeared anti-seize on the metal cable. Slide the outer insulation back and forth to spread it. I also let a set sit in transmission fluid just to free them up, took about a week. My car has spent most of its life in moist climates but it is a common problem. Grease the achor/swivel point generously. I used a very small model paint brush.  After the metal cables free up the anti-seize prevents future freeze and stiffness. It took most of the morning to complete but they work as they did back in 1970. For those that don't have a set of jewelers screw drivers you will see the need if you need to remove interior knobs. As SITEUNSEEN said be patient, everything releases just find the release point. Good luck.

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