That would work!
All that needs to be done is apply 12 VDC to the vehicle.
This can be done with a battery charger, extra battery, etc…
Connect the hot lead to the top terminal of the starter solenoid where the battery cable connects, and the ground to anything metal.
There’s the temporary battery to get the door locks to work.
Tester
I can’t open the hood either…I can’t get to the top of the solenoid. I’m going to try calling a tow truck instead of a locksmith, in hopes they will be more familiar with breaking into cars that the locksmith. Hopefully they can at least get the hood open! Thank you for your instructions! That is exactly what I was looking for! I think the solution for the future is to just not lock the car when I store it for the winter.
If you don’t mind getting dirty and a few scrapes, you could look into opening the hood by seeing where the hood opening cable goes to and working the mechanism. Then you can jump it.
How do you open the trunk normally? Pushing an electrical switch button? Or is it there a cable release gadget? If the latter, you may be able to see the cable path under the car and with the proper type of pliers grab hold of it to pull on it, and open the trunk that way. Same method could be used for opening the hood if the hood has a cable release mechanism. You’ve googled “how to open door on thunderbird with dead battery?”, right? Have you tried asking at a Ford dealership?
There are plenty of professional tools that gain access to a vehicle . . . without picking a lock, smashing a window, opening the hood, cutting the canvas top, hooking up 12V to the starter, and so on
Great idea! I usually use the remote, but there is both a key latch and a pull lever inside the passenger compartment for the trunk. I called the dealership, but the service desk was no help - basically said tow it in and we will see if we can get in it after we charge you the minimum consultation fee. I think the problem is more the door - I think the lock is broken because the battery has been dead before - just maybe not this dead, and that’s how I learned there was a key latch behind the seat.
Right - that’s what I was expecting from the locksmith - I definitely need a tow truck to check it out instead of a locksmith - I expected him to pick the lock, but he said no. I tried the slim jim approach but it didn’t work for me - I can’t find a schematic of the inside of the door to know what to pull and what not to…
I don’t mind a bit - great idea!
That is actually what the service department should say . Making diagnosis over the phone is a good way to make things worse . Also they have to pay their people for the time spent . And if they did give some theory that made things worse that would not be good.
slim jim isn’t the only non-lockpick means of entry . . . not by a long shot
there are tools that don’t even require the tool to get between the door panel and the door skin
I suspect that particular locksmith wasn’t well equipped or wasn’t knowledgeable enough
Here’s what they’re probably trying to use the open the lock.
Forget that.
Just apply enough voltage to the starter solenoid to operate the locks.
You’re going to have jack up the front of the vehicle as if you were replacing the starter.
Tester
I get it - I meant in reply to the people who asked if I called - I didn’t need a diagnosis, I needed a suggestion and they had nothing to offer but to tow it in. I have taken it there before and they were somewhat unhelpful even when the car was there - they don’t see enough of them to know much about them.
me too - especially when he suggested breaking the glass…
A common method of unlocking cars today is to create a gap in the top of the door or window with a small wedge then to insert a small airbag and inflate to spread the opening enough to use a rod to push the lock knob unlocking the door.
You will be asked to sign a release for that states that the lock-out service is not responsible for breakage or damage or it is no deal. Did you decline the service after you were told the glass might break?
The problem with lock out tools that are inserted into the door to push the linkage (I have the obsolete set shown above) is that there are so many difficult door designs over the years it would be impossible for the average tech to master them.
I had a friend that couldn’t get into his truck. The battery had gone dead after sitting all winter,and the neither of the door lock cylinders worked. He had ignored fixing the door locks because he always relied on the key fob.
I was able to charge the battery by connecting the charger to the lead at the starter that went to the battery.
Yosemite
That is going to be my Plan B - I’m going to try to locate the manual truck release cable first and see if I can get the trunk open that way, and if not, then move on to that plan. I’m going back to my storage garage tomorrow to give it another try. Plan C will be to call tow companies until I can find someone to pick a lock. Thank you!
as an idea: try getting a “snake camera” to find out how exactly hood lock works, then use one of prying tools under the control from that camera
What good is getting the hood open if the battery is located in the trunk?
Tester
I missed that entertaining part 
Thunderbird appears to have rimless doors, much like my first 1998 Subaru Legacy clunker I used to own.
The next day after I purchased it, its battery was dead and lock cylinder on the door seem not to work at all (oh well, what did I expect to have from $2700 car?).
I called roadside assistance from my insurance and guy used a small plastic wedge, followed with a small inflatable thing, then used some “hockey stick” thingy to open the door in 3 minutes from the time he arrived.
From watching him work, I was amazed how much flex the glass on a rimless door had and with what low effort it could be manipulated.
My suggestion to OP: let the towing guy to do that, the damage risk is there, but it is minimal.
Is the car parked outside or in a garage/shed?
If it’s parked inside, do you have room to maneuver a jack, so that you can put the car on jack stands?
I don’t particularly like ramps . . . so you’ll never hear me recommend their use
I have a kit like that, and I’m a mechanic, not a tow truck driver . . . which just reinforces my earlier suspicion that the tow truck driver op talked to wasn’t very experience, or maybe he didn’t want to invest money in proper tools to do the job