Re: 1938 Super 8 1605 - adventures with a newbie
Posted by HH56 On 2023/1/21 12:05:02
On the subject of independent coil terminals, here is a breakdown of a later switch showing typical internal construction. As Tim said, most early cars will not have feedback issues because accessories are sparse and electrical paths are simple but later cars, particularly those with more than one power feed to an accessory or an idiot light charge indicator can. Some aftermarket accessories or one improperly connected can also cause issues.
I have not had any junk pre 55 ign switches to take apart so do not have any photos or a precise view of the internal contact action on those but since they have a BAT, COIL, and GA terminal I would wager, with a couple of exceptions, the internal contacts will work exactly the same way as the 54-6 switch. The exception would be that before 49 Packard had no left hand accessory position and before 54 there is no far right start position.
In this 55 switch the contacts are named using modern nomenclature. IGN would be the same as the earlier COIL and ACC is the same as the earlier GA. Obviously the contact plate would be shaped a bit differently on those pre 49 switches where there is no left hand position or on those 49-53 switches without a start terminal.
NOTE: While not applicable to the 38 model this thread is about, as an aside for those having key start cars look on the last (start) photo and see where the contact with the plate is made. Then check the other photos and look at the actual terminal contact point which appears on the photos as a black dot with a silverish color around it. That contact is formed by a raised "bump" pressed into the thin copper bar connecting to the center start terminal. It has a small contact point and on this switch the black dot is showing because it is a hole formed from the bump after metal was burned away exposing the hollow underside of the bump. The burning is due to the heavy current required by the pinion shift starter solenoid used on senior models. The burned away contact and a corresponding melted and warped spot on the plate is the usual reason the 54-6 switches fail. A reason why adding a relay to carry the heavy solenoid current is a good idea.
Attach file:
ign sw.jpg (176.79 KB)
I have not had any junk pre 55 ign switches to take apart so do not have any photos or a precise view of the internal contact action on those but since they have a BAT, COIL, and GA terminal I would wager, with a couple of exceptions, the internal contacts will work exactly the same way as the 54-6 switch. The exception would be that before 49 Packard had no left hand accessory position and before 54 there is no far right start position.
In this 55 switch the contacts are named using modern nomenclature. IGN would be the same as the earlier COIL and ACC is the same as the earlier GA. Obviously the contact plate would be shaped a bit differently on those pre 49 switches where there is no left hand position or on those 49-53 switches without a start terminal.
NOTE: While not applicable to the 38 model this thread is about, as an aside for those having key start cars look on the last (start) photo and see where the contact with the plate is made. Then check the other photos and look at the actual terminal contact point which appears on the photos as a black dot with a silverish color around it. That contact is formed by a raised "bump" pressed into the thin copper bar connecting to the center start terminal. It has a small contact point and on this switch the black dot is showing because it is a hole formed from the bump after metal was burned away exposing the hollow underside of the bump. The burning is due to the heavy current required by the pinion shift starter solenoid used on senior models. The burned away contact and a corresponding melted and warped spot on the plate is the usual reason the 54-6 switches fail. A reason why adding a relay to carry the heavy solenoid current is a good idea.
Attach file:
ign sw.jpg (176.79 KB)
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