Re: Automatic Bilge pump failure?
"You are really reaching here Fishn. Terminal #1 on that switch is not internal. It is an external terminal so the light can be grounded. Terminal #2 (also external) will never connect direct to #3 (also external)"
I do not know how old you are but age brings experience. Some say I am older than dirt. I see you may be an old timer just guessing by the number of your posts. I am sure your advice has helped many including myself. THANK YOU
But don't think just because it is rare that it can't happen.
All terminals on a switch pass through the switch housing to something. So this creates the term internal and external. Internal are contacts, external are wire terminals.
#1 as shown is the contact that the movable internal contact #2 hits when turned on to put power to #1 and end of the internal light lead on a illuminated switch. #2 feeds power to the switch. #3 only goes to the other internal light lead so circuit to ground is completed.
You are really stuck on word semantics and not on actual physical properties of a switch. Any External Terminal on a switch that is designed to hook a wire to, has a function inside the switch too. Therefore the term INTERNAL.
This switch is know as a lighted SPST (single pole single throw) switch.
There are usually 2 contacts on the movable part of the switch INTERNALLY. When turned on, one hits the light circuit and one hits the to DEVICE terminal. They are actually internally modified DPST (double pole single throw) switches
Just to see what brands had better internal construction, I have taken apart similar failed switches that would light but not measure any voltage on the "to device" leg. (more common in cars because of chuck hole jolts)
Internal contact worked to the light but the tiny feeler to the #1 point was bent up, corroded, or high amp burnt, and did not transfer the voltage to the wire terminal.
"possible but highly improbable"
True but like I said in an earlier answer, I did find such a short in an old boat.
Very frustrating problem. Turned out to be a frayed 12 volt feed to contact #1 from another circuit,(bilge blower)and a bad ground at the pump. The frayed area was just behind the shift control mounting location. Wires had sprung from the plastic hangers and all the jiggling finally caused a rub through. If it had only hit a ground instead, it would have blown a fuse and been easier to find. Weird stuff can happen. Ask the crew of Apollo 13 about weird highly improbable electrical shorts.
That was a reply to a posted comment that ALL SHORTS BLOW FUSES. Sometimes they do not. Only all shorts from power to ground blow fuses.
Not arguing with you, just pointing out that there are actually three possible circuits involved that could light the switch but not run the pump.
I thought the original poster mentioned that the light light but nothing happens at the pump.
And since it is an automatic pump and neither the float switch nor the manual override from the dash switch runs the pump, I would suspect a pump motor failure or a bad pump ground. The poster wrote that the dash switch lights. I was showing other very frustrating things that actually can and did cause a similar problem.
"You are really reaching here Fishn. Terminal #1 on that switch is not internal. It is an external terminal so the light can be grounded. Terminal #2 (also external) will never connect direct to #3 (also external)"
I do not know how old you are but age brings experience. Some say I am older than dirt. I see you may be an old timer just guessing by the number of your posts. I am sure your advice has helped many including myself. THANK YOU
But don't think just because it is rare that it can't happen.
All terminals on a switch pass through the switch housing to something. So this creates the term internal and external. Internal are contacts, external are wire terminals.
#1 as shown is the contact that the movable internal contact #2 hits when turned on to put power to #1 and end of the internal light lead on a illuminated switch. #2 feeds power to the switch. #3 only goes to the other internal light lead so circuit to ground is completed.
You are really stuck on word semantics and not on actual physical properties of a switch. Any External Terminal on a switch that is designed to hook a wire to, has a function inside the switch too. Therefore the term INTERNAL.
This switch is know as a lighted SPST (single pole single throw) switch.
There are usually 2 contacts on the movable part of the switch INTERNALLY. When turned on, one hits the light circuit and one hits the to DEVICE terminal. They are actually internally modified DPST (double pole single throw) switches
Just to see what brands had better internal construction, I have taken apart similar failed switches that would light but not measure any voltage on the "to device" leg. (more common in cars because of chuck hole jolts)
Internal contact worked to the light but the tiny feeler to the #1 point was bent up, corroded, or high amp burnt, and did not transfer the voltage to the wire terminal.
"possible but highly improbable"
True but like I said in an earlier answer, I did find such a short in an old boat.
Very frustrating problem. Turned out to be a frayed 12 volt feed to contact #1 from another circuit,(bilge blower)and a bad ground at the pump. The frayed area was just behind the shift control mounting location. Wires had sprung from the plastic hangers and all the jiggling finally caused a rub through. If it had only hit a ground instead, it would have blown a fuse and been easier to find. Weird stuff can happen. Ask the crew of Apollo 13 about weird highly improbable electrical shorts.
That was a reply to a posted comment that ALL SHORTS BLOW FUSES. Sometimes they do not. Only all shorts from power to ground blow fuses.
Not arguing with you, just pointing out that there are actually three possible circuits involved that could light the switch but not run the pump.
I thought the original poster mentioned that the light light but nothing happens at the pump.
And since it is an automatic pump and neither the float switch nor the manual override from the dash switch runs the pump, I would suspect a pump motor failure or a bad pump ground. The poster wrote that the dash switch lights. I was showing other very frustrating things that actually can and did cause a similar problem.
