trouble starting

Does that 77 have a duraspark? is it still bolted to the inner fender with more than one screw? Do you have low spark or no spark ? You can try another duraspark or you can investigate the voltages in the primary circuit and the resistor wire. The public library may still have repair manuals that old by chilyon, motor, or mitchell. some reference libraries even had Ford books donated to them. Since it is almost 40 years old, any loss of the correct voltage in the circuit can be caused by the wires, the connections, or any component.

After those results are known you can investigate the switching if the primary and if you need new guts in one of the finely wired ignition parts, the tests in the book should lead you. be sure of your specs for inputs and your expected outputs. try to use motorcraft parts and you can enjoy another lifetime of joy and beauty in that ride.

i forgot to mention that once i have it running it tends to cut out and die within the first 5 minutes on the road then starts really hard and runs fine till i leave it parked over night

Here is something I found, there may come a time when you may hit start and it turns over fine and starts but when the key returns to the run position, the engine shuts down, I found that if I slowly manually returned the key from the start position in the direction of run .... it will first disengage the start solidnoid, but when held at that point, the engine will continue to run just fine as long as the switch is held at that point, but when allowed to return to run...the engine stops. The ignition switch is defective, and is located behind the instrument cluster.... a real pain !

Is there a warning system in the 2004 thunderbird when the battery is weak..?