HH56 wrote:
In most of their literature Packard treated many switches and relays as black boxes just showing wires going in and out. To save you some time in searching here is the complete 56 TL diagram showing all contacts inside the control switch and solenoids. This also shows the manual switch wired in properly but that switch was a late arrival and an option so may not be on your car.

Note that if you need a new solenoid, even though they look the part they are not the typical starter solenoid you find in the parts store. On the TL solenoids the coils are connected to the battery internally and need a ground on the control terminal to operate. Cole-Hersee has a suitable replacement.