Re: A Tale of Two Patricians
Posted by HH56 On 2021/8/28 21:48:19
Your methodology is fine but the switch is for all practical purposes a direct short between the BAT post and the IGN or ACC contacts so you can use the lowest ohm setting on your meter.
Here is the inside of a Packard switch and the contact layout typical of almost all 4 position rotary switches. This one is a 55-6 switch but the 54 is identical except for the mounting method to the bezel. The chart or the red dots I placed over the contacts show the connections in the different switch positions. You should have zero or a very low ohm reading between BAT and the other terminals depending on which switch position you are in. No reading at all to the terminals not shown as having a connection at a particular position.
Notice the damaged START contact on this switch. The actual contact is on the tab coming off the center post and is the melted blob located right next to the ACC contact. The melted area makes the photo look misleading and almost makes you believe there is a connection to ACC. It does not connect. The START contact also has a relatively small surface area compared to the other terminals yet carries a large current load on cars with the pinion shift solenoids. Hence the suggestion of adding a high current relay to bring in the solenoid instead of the signal coming directly off the switch. The burning and melting on the contact and in the corresponding area on the moving contact plate is typical of the damage Packard switches seem to experience.
Attach file:
IMG_2430.jpeg (41.48 KB)
ign sw.jpg (165.99 KB)
Here is the inside of a Packard switch and the contact layout typical of almost all 4 position rotary switches. This one is a 55-6 switch but the 54 is identical except for the mounting method to the bezel. The chart or the red dots I placed over the contacts show the connections in the different switch positions. You should have zero or a very low ohm reading between BAT and the other terminals depending on which switch position you are in. No reading at all to the terminals not shown as having a connection at a particular position.
Notice the damaged START contact on this switch. The actual contact is on the tab coming off the center post and is the melted blob located right next to the ACC contact. The melted area makes the photo look misleading and almost makes you believe there is a connection to ACC. It does not connect. The START contact also has a relatively small surface area compared to the other terminals yet carries a large current load on cars with the pinion shift solenoids. Hence the suggestion of adding a high current relay to bring in the solenoid instead of the signal coming directly off the switch. The burning and melting on the contact and in the corresponding area on the moving contact plate is typical of the damage Packard switches seem to experience.
Attach file:
IMG_2430.jpeg (41.48 KB) ign sw.jpg (165.99 KB)
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