Interior Air Handling

Okay, now I've got a problem I don't want to have. The cable attached to the lowest of the three dash-mounted sliding knobs is in bad shape. it pushes and pulls VERY STIFFLY. Sunday morning the wire in this cable was bent again, this time badly.

First, I need to see why this thing is so stiff, and I'd appreciate any advice or predictions.

Second, the dealer says the cable is not available separately. the whole (dash airhandling control panel) bundle is about $500. I thought these cables were separately available!

Aaaarrrrgggghhhhhh!

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'83 SC

Salvage yard or eBay.

Jack has become one of my favorite posters here, but he did not tell me what I want to hear. So, I'm still listening....

Also, I'd like to know how to properly lube these cables. Graphite?

And are the cables usually at fault when they operate VERY stiffly, or does the vent mechanism at the other end of the cable fail to operate smoothly? And is there a lube recommendation for the valves controlled by the cables.

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'83 SC



[This message has been edited by Superman (edited 11-20-2000).]

It really ticks me off to find out a $500 module is the only fix offered for a little problem with a $2 part ... except the $2 parts from the past are $20, now ... but I digress!

It seems like if you can EASILY get to the ends of all of those control cables, tag both cable and its' terminating point, then remove the control panel ... without obvious interference from other modules or structure, then do that. Then, luricate all of the flaps, valves, etc. with a spray moly lube that leaves lubricant behind after the aerosol propellant has evaporated. Finally, if the individual cables can be easily removed and reinstalled, spray them with the moly lube from both ends and work back and forth to see if any binding is occuring. I hate to be so generic with suggestions, but A/C systems are not something I work on very often!

One thing I have observed of dealer repairs to these systems is that it usually takes two or three visits to get the initial problem fixed , and the other problems caused by careless or inept technicians in the process. Not Porsche dealers ... but just domestic ones that all seem to fit in the same category when it comes to A/C systems in general! It seems as if these systems are so complex, yet constantly changing, so the technicians really get disgusted at them, and complacency seems to take over ...

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Warren Hall
1973 911S Targa

Hi Superdude, I have heard bout not tryed it myself that you can buy that cable at a gocart shop. It is frustrating to get zapped by a cheap part in an expensive assambly.

Randy Jones
1971 911

A frustrating situation to be sure. Dealer repair was not cheap nor a long term fix - I have the same problem with my 87. WARNING ... do not let this go unattended. In the 87, the bent/looped wire caught the ashtray light wiring, pulled it out of the rubber boot, chafed the wire and I had a real-live under the dash wiring fire on the freeway downtown Dallas in a rush-hour rain storm. Never did figure out why the fuse didn't catch it - but it didn't. Repair was no fun at all!!!!

Superman,

I'm having the same diffucuties with my heater control. After completely removing the flapper valves and fan housing, I rebuilt everything and made certain there was no binding/resistance prior to reintalling. When I still had difficulty moving the slide lever, I completely disassembled the heater control. While there was some dried up lubricant on the control, it did not seem to be terribly difficult to slide. I did find one cable that was kinked. I used the cable from an old choke cable to fabricate a new cable. Prior to installing everything, I used copius amounts of Lithium grease to lubricate the cable and housing. While it is improved, it is still not acceptable in it's operation. At this point, I am thinking I may have to reroute the cables to allow a larger radius as it makes the turn from the passenger compartment into the trunk. Very frustrating to spend so much time on such a small think. Such is life with older cars!!!

Okay now you're talking. Go car shop. Thanks, Randy.

And I also appreciate the commiseration and validation, Warren. Indeed, this does not strike me as a legitimate $500 repair! On the lube subject, are we talking WD-40 or similar? I am concerned that this might make the cables stiff in cold weather. Perhaps that lube is low enough viscosity....

Scary story about the dash fire in traffic.!

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'83 SC

Super,

No, the lube I have is made by TRW, in a gold can, and comes out black and more fluid (lower viscosity) than WD-40, and once 'dry' the moly sticks around to do its job. The aerosol and carrier evaporate within five minutes. There is no oil base to cause swelling.

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Warren Hall
1973 911S Targa

Okay, so what you're saying is that the lubricant is dry (graphite lets say) and is simply suspended in a liquid that evaporates?

I've got some really good ideas here. Let me ask this: The broken thing is the wire itself. Coudl I have a hope of finding and working (properly bending) a piece of wire? As long as I start with the right piece of wire?

I'm such a fix-it cheapskate. But I love this stuff. You know, I'd like to be on Junkyard Wars. I'd sure be happy with some of my PP BB buddies as team mates. We'd kick ass.

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'83 SC

Hey Superman, Your first assumption was right, they are available separately! I was just thumbing through the latest performance products catalog (#48a) and saw a listing for replacement heater control cables (page #227). The part number you need is either 902077 ($19.95) or 902078 ($12.95), depending on your car's configuration. Check it out!

-EJ

Same topic, slightly different question:

After fiddling around with my blower motor, cables, wiring etc, my blower motor now works only at speed II and III. It actuates when the lever is in position I, but blows heavily at the same rate than in position II.
That is definitely too much-its getting snow here today!
Maybe I did a too good cleaning job on the controls...
Anyone have an idea about a reasonable priced fix? (No P car salvage parts availale)

Jens


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Superman, I have the same problem in my car. It hasn't been a real problem since it's the heater flap control, but now that it's winter, I sometimes like a little warm air on the floor. Until now it's been stuck in the defrost position.

Last night I got out there and simply grabbed some of the wire with some needlenose pliers, and shoved it into the cable guide. I did so at night, with the lights on, since there's light behind the dash. I could see the wire perfectly, and now I have heat on both the dash and the floor. It's stuck but it works.

To fix this, you need to replace the actual cable, not just the cable guide. To do this, you have to get at the heater flow director flap - it's certainly different in our cars but it's up there somewhere. Disconnect the wire from the flapper. Cut it with a strong pair of wirecutters - it's piano wire. Do the same at the control end.

Once you have the wire out, go to the hardware store and procure a peice of piano wire of approximately (well, exactly) the same gauge. Get this wire into the guide with some white lithium grease on it and bind it to the posts on either end.

It's *critical* to get the length right. Once you have the wire bound to the flapper, move the flapper by hand to its extreme-defrost position, and with the lever also in that position, measure and bend appropriately.

Warning: I haven't done this! It was the fix described to me by a fellow 911 owner who had the same problem and also didn't want to spend $500 for a new control cluster (I think "cluster" is a great description for this).

Good luck.

Jens, I had the same problem with my fresh air blower. I just sat there with the car off and wiggled it back and forth through that area about 200x. This wore through some of the carbon enough to make contact again. I suppose you could get in there with some contact cleaner, but...Keep It Simple!

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Mark Szabo
1986 911 Targa 3.2

Forgive the flashback here but I'm done fixing this and thought I'd report my findings. I ended up removing the control octopus which is how I should have started. I was able to straighten the bent cable, using a vise, a beer (another vice I suppose), heat and patience.

All the cables have one straight end, so you can slip the sheath off. I used plain graphite after cleaning them. They're smooth as silk now. I was unable to remove the driver side control box with the brake MC in the way, so working behind it was tricky. I used more beer.

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'83 SC