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Phantom electrical issue?

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24 minutes ago, KongaMan said:

Which begs the question: which circuit is heating up?  The ignition doesn't draw that much current; it is likely the accessories which are responsible.  Although a lot of the high-draw components (windows, lights, etc.) don't go through the switch, those that do (blower, etc.) are substantial enough to put a strain on the wiring.  You could probably get away without a relay on the starter circuit.  Even though it's a long run and a heavy draw, it's a really short duty cycle (might save your neutral safety switch, though).  In any event, you could probably eliminate the warm key problem with one relay. 

The combined amp draw of all the circuits which are not unloaded thru a relay enter the switch via the red battery lead wire...so that wire, because it carries all the amps into the switch, shows the effect of heating and cooling before the other wires which feed individual circuits.

As I stated in my first post, there is a possibility an issue on any of the circuits could cause the overheating/excessive amp draw thru the switch but I have seen this sort of deterioration when all is well more frequently as compared to a short or excessive amp draw.

  Tom

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13 minutes ago, 1965rivgs said:

The combined amp draw of all the circuits which are not unloaded thru a relay enter the switch via the red battery lead wire...so that wire, because it carries all the amps into the switch, shows the effect of heating and cooling before the other wires which feed individual circuits.

As I stated in my first post, there is a possibility an issue on any of the circuits could cause the overheating/excessive amp draw thru the switch but I have seen this sort of deterioration when all is well more frequently as compared to a short or excessive amp draw.

  Tom

 

That's true, but there won't be nearly as many amps going through that red wire (or the switch) if the ACC feed goes to a relay instead of directly to the fuse box. If you think that deterioration is a function of current draw, then putting a relay on the ACC circuit will help to mitigate a problem with the battery lead.  The other high draw circuit feeding from that red wire is the starter.  Put a relay on that circuit as well, and you reduce the maximum current through the red wire and switch to a fraction of its present value.  At that point, the only current through the red wire, switch, and connectors would be that required to power the ignition and two relays.  That low draw shouldn't present any problems at all.

 

One might also suggest that if you see deterioration at the red wire, then by definition, all is not well.  IOW, you're seeing the failure of an under-engineered component.

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23 hours ago, KongaMan said:

 

That's true, but there won't be nearly as many amps going through that red wire (or the switch) if the ACC feed goes to a relay instead of directly to the fuse box. If you think that deterioration is a function of current draw, then putting a relay on the ACC circuit will help to mitigate a problem with the battery lead.  The other high draw circuit feeding from that red wire is the starter.  Put a relay on that circuit as well, and you reduce the maximum current through the red wire and switch to a fraction of its present value.  At that point, the only current through the red wire, switch, and connectors would be that required to power the ignition and two relays.  That low draw shouldn't present any problems at all.

 

One might also suggest that if you see deterioration at the red wire, then by definition, all is not well.  IOW, you're seeing the failure of an under-engineered component.

You asked "which circuit is heating up?" My reply was to point out that the heat is being generated on the feed of the switch, not a switched circuit. Is it possible one of the switched circuits is the culprit? I`ve already stated so several times in this thread because I have found this to be true in isolated cases.

My reference to "all is well" was in regard to the switched circuits operating as originally intended, not the original engineering of the circuit as a whole. Was the circuit layout poorly engineered? Maybe. Are the cars well beyond their intended life cycle? Definitely.

 To add a relay to reduce load on a switch when needed? Seems like overstating the obvious but sure, knock your socks off...

Tom

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On ‎1‎/‎31‎/‎2018 at 12:01 PM, 60FlatTop said:

a psychiatric term called "flat surface syndrome" 

As a very good friend says, "horizontal surfaces are the enemies of order" and I'm living proof!

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33 minutes ago, 1965rivgs said:

You asked "which circuit is heating up?" My reply was to point out that the heat is being generated on the feed of the switch, not a switched circuit. Is it possible one of the switched circuits is the culprit? I`ve already stated so several times in this thread because I have found this to be true in isolated cases.

Understood.  The point is that the circuits coming from that main feed do not draw equally.  As such, remediation efforts are best directed at the circuit(s) which are responsible for high draw.  In that same vein, it's not just possible that one of the switched circuits is the culprit; it's inescapable.  Drop the current through that connector and switch, and the problems disappear. Look at it this way: if the key gets warm and the connector from the battery feed to the ignition switch is burned, pitted, and/or melted, do you just let it go until it burns through or catches on fire because it still works? ;)

 

It should also be mentioned that there are ancillary benefits to adding relays to the ACC and/or starter circuits.  To wit, you'll see better performance from the high draw accessories (blower, wipers, etc.) and the starter as you lessen the inherent voltage drop in the original circuit.  You'll also prevent damage to other components (e.g. NSS and ignition switch).  Folks don't seem to think that adding relays to the headlight circuit is ill-advised or excessive. Are the reasons for that not the same as the reasons for addressing the same problem in the ignition switch?

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