Well, I drove the 57 that I recently pulled from hibernation some more and encountered a couple issues last weekend electrically and wondering if they are related, or if this has been encountered by anyone else? First, a taillight bulb (signal) went out, so I went to the parts store to replace it, but they didn't have the same number. There was one that looked the same, so I tried it. It worked briefly, then blew the fuse. I thought at first that maybe it wasn't the correct resistance, but the fuse looked like it was pretty crusty not being used for 30 years, so I replaced it with the correct amperage and tried again.
I then drove the car around, parked and left the signal on a minute, and no problems. However, when I went to turn the car off, it kept running. Is this likely the ignition switch shorted or is there a more likely place? I would think this is an unrelated circuit and unrelated to the taillight problem, but is there any possible connection or is it just coincidence? I am hoping to try and find the problem this weekend. Any suggestions?

I have a '57 Super that did that. It seems that there was a starter circuit modification on later models but would still bolt up to the '57. When this was the case, after starting, the engine would not shut off. I disconnected the #16 ga yellow wire that run from the starter to the terminal block next to the voltage regulator. Problem solved, short of replacing the starter. I believe it might be worth a try in your case.

Dan
'57 Roadmaster
'57 Super
'63 LeSabre

This exact problem happened to a friend of mine last year.
His car wasn't a 57 Buick it was a 60's chrysler but the symptom was the same.
He had to replace a fuse for the wipers when it blew and tried to do so at night time so he could drive the car home in the rain.

He pulled the blown fuse and replaced it with a good one while straining to see under torch light. He then started the car.......wipers worked fine and off he went home. Got home and tried to turn the car off and it would not turn off no matter what he did in the end I think he had to disconect the battery.
I won't go into the full story of what he did to the cat to try to rectify the problem but he spent a lot of time and head scratching wondering what the heck was wrong

He decided to retrace his steps starting with the fuse box and found that the new fuse was sitting wrongly in the fuse box.
Instead of being in it's correct position it was sitting in between the wiper fuse position and another(I'm guessing ignition?) and so it was effectively hot wiring the car so that once it was turned on it was preventing it from turning off.

I don't know the layout of a 57 fuse box or if the same scenario is possible but the stories are so similar I thought I would share his story just in case that may be your problem.

Before you go pulling everything apart and attacking starters etc have a look at the positioning of the fuses to ensure no crossover has happened.

As my friend said in the end.............it's most always the simple things that cause the problem and very often they are overlooked because we think something more dramtic has happened.

Hope you have success

Most of the time this problem is the small wires on the starter solenoid get twisted when being tightened and come into contact with the main terminal for the battery cable. Loosening these wires and retightening being careful to ensure there is no overlap to the battery terminal straightens the situation.

However, if your car was right before changing the fuse for the signal lights then I would not suspect this. Instead I would inspect the wiring harness near the fuse box. If you had to push on this to get access or change the fuse then maybe you have a broken wire in there now? I think the 57 ignition is nothing more than a toggle switch, like my 56.

It does sound possible that this may be related to something at the fuse panel after hearing these stories - thanks for the sanity check! I also remember that there was a nearby fuse that was not all the way in and a pushed it in. I wonder if doing so caused it to make contact with a nearby fuse when the clips expanded?

I didn't get to solve the problem this weekend, but I drove it again to see it the same thing would happen. The first time I went to shut it off, it turned off no problem. After that when I got home, same problem over and over! I finally pulled the coil wire to shut it off. I'll check it out and post back.

On the back of the 1957-1958 ignition switch there is a little particle board or bakelite cover which is held in place by two or three crimped over or bent metal tabs. After many years of use, the particle board or bakelite can develop some low spots, which allows it to rotate just a bit under the metal tabs when the ignition key is turned. When I had my '58, I found that the backing of the ignition switch was turning just enough to (in my case) keep the car from switching on to start it. A combination of some good glue and a deeper, harder crimp or press onto the metal tabs fixed the problem, though it is/was not a permanent solution.

Pete Phillips, BCA #7338
Sherman, TX
1949 model 59
1950 model 76-R (two)
1963 Wildcat 4-spd. conv.

Another way to kill the engine would be to manually push up on the choke linkage which will flood the engine. It's a lot less shocking than yanking the coil wire..

I am happy to report that the problem is solved; thanks for all of the input! As it turned out I sort of got lucky (that it wasn't too difficult to solve). I checked the fuse panels and didn't find any problem there. It occurred to me that the problem was to a degree intermittant, plus a battery drain issue developed suddenly, which made me believe that the explanation given by Pete Phillips was the cause. I bought a new ignition switch and installed it this weekend. It works!! Finally the car starts, drives, and shuts off as it should!