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August 27, 2020

1963 Issues With Fuel Gauge Reading

Bill -

The fuel gauge on my 63 Sedan was inop. I ordered a new fuel tank sending unit from Lincoln Land. When I installed the new sending unit it only reads 3/4 or slightly less, when the tank is full. I also replaced the constant voltage regulator. The service manual says to substitute a known good unit to verify the problem. Since I only have one unit, that is not possible. When I ground the sending unit wire to the body of the car the gauge goes past full. I pulled the sending unit back out and measured the resistance. When the float is moved to the full up position as would be a full tank of gas it reads 5 ohms from the terminal to the body of the unit. My question is, will you take a known good sending unit and measure the ohms of the unit when the float is moved to the full position? This would help me troubleshoot the problem Before the old sending unit wore out it would read full when appropriate.

Thanks,

Jeffrey

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Hello Jeffrey -

Some of these electrical problems can be frustrating. We can check our Sending Units here at Lincoln Land but there is another way to test your new sending unit first. Remove the new unit from the tank, plug the wire from the dash gauge in to that tank unit and ground the body of the tank unit. Turn the ignition on a then operate the tank unit by hand from empty to full. Observe the dash gauge to see if it now can reach the FULL and EMPTY mark during the test. If it cannot read full at this time, the sending unit is faulty or its rod is bent or the float is defective. Another possibility is that the constant voltage regulator in the dash is defective. With the key in the on position probe the sending unit wire at the gas tank. This cvr sends out a flashing or pulsating signal to the tank unit. If this signal is not clearly observed at the fuel tank wire the cvr could be defective. Do not directly ground out the cvr wire as a test as this could be detrimental to the gauge. Please be very careful while working near the open fuel tank in order to avoid a fire. Let us know what you find.

If you have any further questions or do not fully understand the above suggestions regarding diagnosis please do not hesitate to call Lincoln Land and ask for George. He will get one of our techs to discuss the matter with you. Together we will get it working properly as this is a common issue with gauges.

Sincerely,

Bill

August 25, 2020

1976 Town Car Question About Starting

Hi Bill,

I have had two separate mechanics tell me, that my carb / choke is fine, although it takes about 6 or 7 cycles to get it started from a cold start. It is only driven once a week. My question is ? should I have to pump the gas, in that many cycles to get it started ?

Michael

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Hi Michael -

Those 76 Town Cars sure are nice vehicles, especially when everything is working as designed. For your starting problem, have your mechanic observe the choke plate while cranking the engine "cold". The choke should not open at all while cranking cold. If it does, it could be set too lean. Next the choke should be opened by hand and the accelerator should be operated while the engine is off and cold. The fuel spray should be observed for abundance. If the spray is weak, the accelerator pump in the carburetor could be weak and/or the fuel pump pressure is weak.

If the car has been sitting around and not driven very often you can expect some fuel delivery problems between the fuel tank and the carburetor. If all is well you should not need to pump the accelerator more than a few times. The above is based on your information above and assuming that all of your tune up electricals etc. are in good order. good luck with the diagnosis and we will have any of the items that you may need for that 76.

Sincerely,

Bill

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Bill -

Thanks for the tip, my mechanic discovered a fuel filter leak and that seems to have helped tremendously with the cranking.

Michael

August 24, 2020

'75 Mark IV Blower Works On Max Only and ....

Hi Bill,

I've been reviewing your blog with enthusiasm over the last few days. In summer 2008 I resurrected my father-in-law's 1975 Mark IV after it had sat for 17 years. I bought a few parts from you then and they did the trick nicely! We drove it as a toy for a couple summers then had to park it again due to life... until I brought it to our "new" home in 2017. Anyway this car has been a learning experience for me: first carburetored car (from the big 3's nadir, off) and all that, but I've managed to sort it out by attacking one issue at a time. It looks great and runs smooth and even won a trophy at a local show.

Anyway, I'm hoping you can lend some advice for two issues. I know you are busy so I will try to be brief, but detailed... it's a tough balance so please bear with me.

For further background: the car has 82000 miles and had a blown #8 exhaust manifold stud and gasket, which made it tend to run hot. I finally got the gasket fixed (no easy task with all the broken studs), then rebuilt and tuned the carb myself (no easy task for someone learning). The car has ATC of course and the A/C has never worked in my time - I'm sure the coolant leaked out ages ago or maybe the compressor is shot, but it's not a priority before getting the car running right.The heat works well and is quite roasty - but the blower only works on max.

1) So the blower speed (max only) is my problem. I have the set of orange '75 FoMoCo manuals and based on reading them and your blog, have tested / confirmed:

- Under-hood blower relay works. When I jump the harness (Or/Bk to Gr) wired to run the blower on low, nothing happens

- I checked the blower resistor pack. There are 3 resistor modules. They all bench test good with a meter, two at ~62 ohms resistance and one at ~50 ohms. The spring contact in each module works. The 3-prong module has a diode, which measures OK.

- The servo sensor was filled with a bug nest back in 2008 and I'd cleaned it carefully. The bimetal springs, etc all look clean and flex nicely.

- I checked the Servo Motor & EVM module by removing it from the plenum and observing its operation. I opened its electrical switchboard module and discovered its contact board was fairly well blackened, so cleaned it up. If I start the car I can watch the vacuum modules work - granted, I realize they may not be in spec but at this point I'm trying to get the blower to work electrically*... by ensuring the electrical sled from the servo motor was moving. Unfortunately, the blower still does not activate with the control set in the auto position. I had the system (vacuum) set to Vent and 75 deg, but I manually moved the switchboard sled and could not trigger any response from the blower - HOWEVER I could hear the EVM module pulse and/or click as I moved the swtichboard contacts, so it seems my cleaning did some good.

*I don't have a vacuum tool handy. However, by observing the parts loosened from their mounts but connected to their hoses, I could observe their relative function which "seemed" OK. (if I manually push on the sniffer sensor, I can observe the servo respond, etc). No audible vaccum leaks and if I disconnect hoses, the engine stumbles badly.

Anyway... that's a bit of a ramble gut given how this ATC system tries to read ambient conditions and engine status... surely I don't need the A/C part(s) fixed for this to work, do I? Or did I overlook something stupid? I plan to get a vacuum tool shortly but meanwhile I was doing the best exploration I could with the tools I have.

Also I should mention, while the blower does work on Max, it makes an awful screeching noise for the first 15 seconds or so (sometimes longer). I'm assuming it needs replacing soon anyway, but that doesn't explain the lack of low speeds? (Hopefully you can appreciate I am trying to identify "anything/everything else that might need replacing while I'm in there).


2) Back to that "wow but the heat is roasty": As nice as this car is for its time, I absolutely hate how FoMoCo cheaped out with a single idiot light for temp/amp/vacuum. And knowing it was running hot while it had the exhaust leak... call me paranoid but I'd like to add a triple-gauge set for Temp, Amps, and Oil pressure. Of course I now understand the single stock temp sending unit is critically integrated to the ATC and other functions, so I can't just plug a different one in its place. Surely I can't be the only one who's attempted this, but I don't see any resources online. Can you recommend a location to tap for temperature? I'm thinking of tapping into the cabin heater inlet hose, as that would be easy and reversible, and temps should not be much different from the thermostat / radiator. I didn't see obvious available locations in the manifold (which might still present other clearance challenges).

3) I'm sure this goes back to me "learning" the carb but this car is very hard to start after it sits for a few days. Takes 30 seconds or more of cranking (I use 6-second cycles to preserve components). I've read and followed the rebuild and tune guide over and over and can't seem to get anywhere. It runs OK, and starts fine when warm. I replaced the fuel pump in 2008.

Well anyway I apologize for the dissertation. I hope it at least gave you enough information to consider some advice but if you need any more info, please ask. Thanks again for your service and expertise! I've attached some pics of the car... I called it the "Angstmobile" when getting it running. I let my 15yo daughter practice some 3-pt turns with it the other day, too. Also, I am led to believe the Pastel Blue / Navy combo is fairly rare, and when it came time to replace the cluster bulbs, I went with light blue LEDs to match the car and arguably "update" it a bit.

Kind regards,

Tony

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Greetings Tony -

Welcome to Lincoln Land and Bill's corner. It is good to know that you have the correct manuals for your Mark IV. They are among the best tools in your toolbox.

The blower motor on your Mark uses a completely separate circuit for the lower speeds. For max. the power is from a fuse link directly from the battery and through the High Blower relay. For the lower speeds and the other ATC controls there are two fuses that are located in the fuse box. Your information regarding the blower squealing for a period of time is important for the diagnosis as this indicates resistance. It is "possible" that because of this resistance the blower motor cannot turn with the lower voltage of the lower speeds.

You should begin by testing the circuit as shown on page 36-74-6 of your Electrical manual with a 12v test light. Start by testing for power at the blower motor with the engine off but warm and the key switch on. Turn the ATC on and select a lower blower speed. With your test light check for power at the blower motor connector. If there is power but no blower operation the motor would need replacing or lubrication. A draw test on the blower at this point would also be a good idea.

If there was no power at the motor connector, test the fuse box fuses. If they are good, you will then need to test the circuit to and from the Hi Blower relay through the resistor and all of the switches etc. with the test light. When testing watch for burnt connections and/or melted plastic. After the repair a blower motor "draw" test is very much advised.

To answer your other question, the actual refrigeration system does not need to be operating at all for the blower to work properly.

If you are installing some sort of aftermarket temperature gauge, my opinion as yours is that the hot heater hose close to the engine could be a good location to tap into.

We will have any of the ATC parts that you may need as well as a new blower motor here at Lincoln Land for you as required. We wish you the best of luck with the testing and diagnosis.

Sincerely,

Bill

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Hi Bill,

Sorry for my delayed response here, but I'd like to thank you very much for your prompt reply. What you suggest makes sense, and hopefully I'll have some time this weekend to poke around again for follow up and let you know how it goes with the blower circuit. Thanks again!

-Tony

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Hi Bill,

As promised, here's some follow-up: After thinking about your hint that "possibly" a weak motor would have too much resistance to work on lower speeds, and what I already knew about the car's 80K historic miles sustained under smokers, farm dust, and who-knows-what else... I decided to finally dig in and remove the blower motor as I'd actually been meaning to for a while, but wasn't looking forward to the job. Well, after finally getting it out, I guess I should be shocked and amazed that it even worked at all?! I was instantly greeted with lots of debris, rust scale, caked dust and ash, and who knows what else. The wheel is somewhat difficult to turn by hand and there is a definite drag spot somewhere in the armature. Once I get it turning, and removed the wheel, the bearings squeal even by hand. But arguably the worst telltale of all is I could not separate the harness plugs for the orange wire: the "car side" wire lead pulled out of the harness, and eventually with it removed from the vehicle, I can now see they melted / deformed together (so much for using the test light at the connector)! See attached photos....

So it looks like a new blower motor is in my future regardless of the overall ATC health. The wheel will clean up nicely, but the shaft retention spring clip launched itself to the nether as I attempted to set it down after removing it.

If you'd like to quote a replacement motor and wheel clip, and perhaps the harness connector(s) (I may yet be able to separate and salvage the originals, or use standard connectors if need be) I'd be grateful. Everything else looks OK thus far, and the fuses look good too.

Thank you,

-Tony

(PS and BTW, FWIW I am no stranger to difficult DIY repairs in tight spaces (Fox-chassis heater cores; steering rag joints, removing transmissions and engines, etc etc etc) but getting the two rearmost screws out of that lower blower housing ranks up among the most sanity-checking miserable tasks I've endured in a while! I'm embarrassed to admit just the one of them took me almost an hour of struggle and contortion to find the magic balance of reach, fit, bite, and angle. Hopefully it goes back together more easily!)

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Hi Tony -

We were happy to see your reply and that you have found a definite problem ( actually several problems ) and a new plan of attack to cure your blower speed issues. With the installation of your new blower motor that you ordered at Lincoln Land today along with the repaired electrical circuit, that part of the Automatic Climate Control should work as good as new.

Sincerely,

Bill

August 11, 2020

1966 New Owner Brake Light Question

Hi Bill -

I recently purchased a 66 Convertible. One thing I noticed is that the left side brake lamp doesn't not operate. Running lights and turn singles work in the left side, and all functions of the right side work. Just no left side brake light. Changed all the bulbs and cleaned all the sockets. I traced the wire harness I. The trunk and all seems to be OK. Any ideas? Thanks for your help.

Christopher

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Hello Christopher -

The brake lights and turn signal lights are more complicated than you may suspect. Power to the brake light indicators originates from the turn signal switch. This switch is a common problem and therefore is a good place to start diagnosing. This switch can be diagnosed using the correct FoMoCo wiring diagram and a 12v test light. Another quick way is with the turn signals in the off position to press on the brake pedal and using the test light check for two wires ( left and right brake lights ) at the t/s connector located in the lower steering column connector becoming live with the brake light depressed. If only one wire becomes live, I would then suspect the T/S switch and check it further.

Be advised that in 1966 Lincoln used two completely different steering columns and t/s switches. One for the standard column and one for the Tilt Steering wheel option. The tilt wheel option was actually a GM unit. We usually have parts available for both although the tilt wheel switch can be sometimes difficult to locate.

Let us know what you find out with your diagnosis.

Sincerely,

Bill

1978 Continental New Owner Question - Autolamp System

Hi Bill,

I purchased my '78 Continental back in April to give me something fun to tinker with during these times (I've nicknamed it the COVID cruiser!). It is not my first older car but it is my first Lincoln. I purchased an entire set of factory service manuals to help me tackle a myriad of small issues that I've been able to correct one at a time. Everything works on the car now except for two items: the power door locks (which I've successfully diagnosed but haven't got around to fixing yet) and a feature of the Autolamp system. It turns on and off as expected (regarding ambient light conditions) when the car is turned on and the Auto-dim feature also works. The issue is with the delay-off feature. Aren't the headlights supposed to stay on for a certain length of time determined by the left-hand flag dial after the car is shut off? I cannot get this to work and I’m stumped. The headlights turn off immediately when the car is turned off, regardless of what position the flag dial on the le ft side of the headlamp switch is placed. Any direction is appreciated.

Thank you!

Adam

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Greetings Adam -

Yes, you are correct that the lights should remain on for a short period of time when the key is turned to the off position according to the setting on the Headlamp switch control tab. It is great to hear that you have the correct factory manuals. Your Autolamp lighting system operation should be explained along with diagnosis procedures in the electrical section.

Assuming that your Autolamp has not been tampered with and I had to guess I would first suspect that a faulty Amplifier Control Module is causing your issue. Let us know what you find.

Sincerely,

Bill