1976 Town Coupe Auto Temp Control Questions

Hiya Bill,
I have recently become the owner and custodian of an exceptional 1976 Town Coupe, ex California car with 67000 miles on the clock, last owner 37 years, (from 12 months old), spare never down, jack never used, and completely original. What a find! Cannot believe it. It arrived over here in the UK end of November 2014, and was ready for collection in January 2015. After lighting mods., service and under seal, the car swept though it’s MOT with flying colours, needing nothing. Few modern cars achieve that. Testimony to how well it had been looked after.
The journey from London to my home in Blackburn, Lancashire, (230 miles approx.), passed without a hitch, apart from a rough tick over. Work then started on the, yes, you guessed it, the Ford 4350 carb., which was flooding, and leaking fuel due to warping. Thanks to splendid advice from your very own John (Haroll), and carb., repair kit and filters etc., from Lincoln Land, and a certain cold weld product, the car now runs, dare I say it “like a Rolls Royce”, only better!!
I have added a couple pictures for you. You are more than welcome to add these to your web site, if you so wish. If you would like any more information about the car please do not hesitate to ask. I could go on about it all day, but don’t want to take up too much of your time.
I am hoping you may be able to help with the only problem I have with the car at present, which is more of an aggravation than anything else, and it’s a “chattering” noise coming from the ATC box as the unit modulates the incoming air temp. The unit works fine in all functions, and does what it should, the A/C is cold and quiet, but as the temperature control is increased from 75 degs., onwards the “chattering” noise comes in with the increase in air temperature, and changes in frequency as the vacuum modulates. I have had a vacuum gauge connected to the Tan vacuum lead to the heat door motor, and at 65 degs., it seems to be pulling 15 ins, and steady, but as you increase the temp., the vacuum becomes erratic from about 75 degs, varying by about 1 – 2 inches at approx.,10 ins., accompanied by this “chattering” sound, and then becomes steady again and quiet, down at around 3 ins., and 85 degs. So it seems as though unsteady vacuum supply is causing components within the ATC box, and linkages to vibrate. You can actually “feel the noise” by touching the ATC box and the heat door vacuum motor. The noise is still present with this motor disconnected. Could a faulty transducer be the cause? Have you experienced this on other Town Cars of this era? Any suggestions would be very welcome. ( I wish I lived around the corner from your workshop!). I have all the manuals, and as an engineer, am reasonably adept as sussing out most problems, but this is causing some grief. One problem that I do have, is getting the car to an ambient temperature of 70 – 80 degs F, to carry out the sensor resistance checks as per the manual. The car is too big to work on inside, (without resorting to a retail garage workshop – who probably would not know what to do with it anyway! ) and of course we rarely see ambient temperature of 70 degs F in the height of summer, let alone October! However the system does seem to provide incoming air temperatures as per that demanded by the temperature resister.
I hope I do not presume too much in contacting you regarding this matter, but as winter approaches, I will be needing heat rather the A/C for quite a while, and would like it to be provided relatively quietly if possible!
Thank you for taking the time to read this message, Bill
Kind regards, (my best wishes to John too)
Jim
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Greetings Jim –
That era of Lincolns offer some of the most luxurious and spacious vehicles ever produced. Yours sounds like a real beauty and should provide you with many years of motoring pleasure.
Your issue of the annoying “ATC box chatter” is a very common complaint these days as the systems age that actually began to appear on some units after the introduction of the Automatic Climate Control many years ago. Back then new repair parts were available to cure these and other ailments. Fortunately we at Lincoln Land are able to rebuild these ATC Boxes and do a complete internal tune up inside in a way that they will operate better than new. All failed non re buildable parts are replaced with rebuilt components and the finished assemblies are pre tested before returning them to the owners. The Factory Service Manual outlines all of the necessary tests for the Climate Controls but we find that 99.9% of these boxes require extra specific service internally. It is not uncommon for some vehicles to have two or three faults as well in other climate control components but your description indicates to me at this time that your problem is located only within the ATC box. These boxes are not repairable by anyone who is not fully experienced and therefore must be sent in for proper service, or we can make arrangements to send you a repaired unit in advance with a Core Charge. If you decide to send it to us please include my name in your cover letter so that I can discuss your system with our technician before returning the unit to you. In the mean time, please enjoy your Lincoln.
Sincerely
Bill
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You are a STAR, Bill & Erik.
The new ATC box is fantastic. I thought the original box was working reasonably well, apart from the chattering. How wrong I was. The new box has made an unbelievable difference, and I can now appreciate how good the old system is. The heater does not start until the engine is off full cold, as it should, the heat output is excellent, as is the calibration, i.e., achieving the required 80 degs F(approx.) cabin temperature, with the rheostat set at 75, and the set temperature is maintained to a very satisfactory level. All in peace and quiet. The A/C seems to be OK too, although the weather here is not conducive to ice cold air at this time!
All in all, a most satisfactory result. The guys at Lincoln Land are to be congratulated on an excellent standard of refurbishment, and please pass on my thanks, and tell them I am very pleased with the unit.
I will now pack up the old unit (Core), and send it over to you. Although the shipping costs are somewhat prohibitive, I may as well let you have the unit to re-build, as it looks in good condition, although obviously needs work inside, and it is a shame to throw it away. I will let you know when I do send it off. Should be this week some time.
Thanks again for the good advice and great service,
Kind regards to all,
Jim