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Hello,
this is the second time I have noticed my change over switch melted. What could be the possible cause?
attach photos for reference and help to resolve this.
The slide-on connection method used on the contact pins is a poor design. They are subject to becoming loose. Poor connection = high resistance = high heat = meted switch
The slide-on connection method used on the contact pins is a poor design. They are subject to becoming loose. Poor connection = high resistance = high heat = meted switch
Cheers
DD
DD, how could this be prevented from occurring when I replace the switch?
Hi,
I would check with David about another switch and plug which I believe you have already replaced before ? I can see it was spliced / taped together in your pictures. I would install the "new" plug wires by first crimping with butt connectors then soldering the wires into them and finally heat shrink tubing over everything. Might be overkill but I tend to do that alot ! The circuit does not have any fuses etc for protection so it needs all the help it can.
I'll try to upload a picture of the circuit, but basically the big white wire should be the feed from the ignition switch and the white with purple stripe goes to the three fuel switching valves.
"Off=left" should pull and return fuel to the left tank, and "On=right" should energize all three valves switching them to use the right tank.
It could be a loose connection as mentioned above but I would check the resistance of the white+purple wire ( unplugged from the switch ) to ground to see if it or one of the valves is shorted to ground. It should be between 3 to 6 ohms to ground at the switch.
I checked some of my old valves and each one individually measures between 10 to 18 ohms but they are in a parallel circuit, so they are equivalent to / measure 3 to 6 ohms when installed together.
This means the total max current should be 2 to 4 amps going through the switch when using the right tank. You can also test this with a Amp meter in series. If the hot wire or one of the valves is pinched / shorted to ground somewhere then unlimited current will try to flow until something melts !
DD, how could this be prevented from occurring when I replace the switch?
Take a small, pointy tool...you decide what kind....and carefully press against the small eyelets in the connector to make them a bit smaller. This will allow them to grip the pins on the switch more firmly
Hi,
I would check with David about another switch and plug which I believe you have already replaced before ? I can see it was spliced / taped together in your pictures. I would install the "new" plug wires by first crimping with butt connectors then soldering the wires into them and finally heat shrink tubing over everything. Might be overkill but I tend to do that alot ! The circuit does not have any fuses etc for protection so it needs all the help it can.
I'll try to upload a picture of the circuit, but basically the big white wire should be the feed from the ignition switch and the white with purple stripe goes to the three fuel switching valves.
"Off=left" should pull and return fuel to the left tank, and "On=right" should energize all three valves switching them to use the right tank.
It could be a loose connection as mentioned above but I would check the resistance of the white+purple wire ( unplugged from the switch ) to ground to see if it or one of the valves is shorted to ground. It should be between 3 to 6 ohms to ground at the switch.
I checked some of my old valves and each one individually measures between 10 to 18 ohms but they are in a parallel circuit, so they are equivalent to / measure 3 to 6 ohms when installed together.
This means the total max current should be 2 to 4 amps going through the switch when using the right tank. You can also test this with a Amp meter in series. If the hot wire or one of the valves is pinched / shorted to ground somewhere then unlimited current will try to flow until something melts !
Hope this helps !
Cheers,
Brian
Hi Kuzu
great info and I would be glad to use the left tank for now till I get in another switch so kindly send me the picture of the switch so I can find it and do the switch off to use the left tank
Hi,
I would check with David about another switch and plug which I believe you have already replaced before ? I can see it was spliced / taped together in your pictures. I would install the "new" plug wires by first crimping with butt connectors then soldering the wires into them and finally heat shrink tubing over everything. Might be overkill but I tend to do that alot ! The circuit does not have any fuses etc for protection so it needs all the help it can.
I'll try to upload a picture of the circuit, but basically the big white wire should be the feed from the ignition switch and the white with purple stripe goes to the three fuel switching valves.
"Off=left" should pull and return fuel to the left tank, and "On=right" should energize all three valves switching them to use the right tank.
It could be a loose connection as mentioned above but I would check the resistance of the white+purple wire ( unplugged from the switch ) to ground to see if it or one of the valves is shorted to ground. It should be between 3 to 6 ohms to ground at the switch.
I checked some of my old valves and each one individually measures between 10 to 18 ohms but they are in a parallel circuit, so they are equivalent to / measure 3 to 6 ohms when installed together.
This means the total max current should be 2 to 4 amps going through the switch when using the right tank. You can also test this with a Amp meter in series. If the hot wire or one of the valves is pinched / shorted to ground somewhere then unlimited current will try to flow until something melts !
Hope this helps !
Cheers,
Brian
[QUOTE=Doug;2384486]Take a small, pointy tool...you decide what kind....and carefully press against the small eyelets in the connector to make them a bit smaller. This will allow them to grip the pins on the switch more firmly
Cheers
DD[/QUOTE
Thanks DD, I will do as directed when I get in the switch
Hi Mike,
The switch is the one shown in your pictures. Because the plug / connector is melted and maybe shorted inside, I would disconnect or cut the solid white wire going to it that is wrapped in black tape in the pictures. Make sure the end is taped or covered with a wire nut to insulate it since it will have 12V anytime the ignition switch is on. You can then safely use only the left tank until getting a replacement plug and switch, assuming none of the three fuel valves are stuck in their "energized" = right tank position. They should be okay, otherwise you should have already had problems with fuel going back to the wrong tank and overflowing etc.
Change-Over switch melt
