When I first got my 318 the ignition switch was acting up. I installed a new switch and it helped for a while, but the problem returned. I looked at the schematic and in the "run" position they have a 3 amp and 20 amp fuse feeding the tractor circuits. This seems like a lot of current to be passing thru the switch contacts. I installed a relay which has a contact rating of 30 amps. I installed a wired socket that matches the relay. Now the ignition switch "run" only activates the relay coil. One of the contacts of the relay connects to the 25 amp circuit breaker and the other contact connects to the 3amp and 20 amp fuse that used to connect to the ignition switch.
Ignition switch improvement
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Larry,
That modification should dramatically increase the life of the switch -- potentially more than just the "starter improvement kit" which uses a similar relay to offload the switch from the high current drawn by the starter solenoid.
In a 318, the other major loads are the PTO (about 3 to 4 amps each...and most 318 tractors have only the front one fitted) and the headlights. Since these loads are not typically on when the key switch is moved to the RUN position, the key switch contacts only must carry the loads when active -- not switch them. In any event, your modification will help.
Does your tractor have the starter improvement relay added also, or was that solenoid load contributing to the early demise of your last key switch?
Chuck
That modification should dramatically increase the life of the switch -- potentially more than just the "starter improvement kit" which uses a similar relay to offload the switch from the high current drawn by the starter solenoid.
In a 318, the other major loads are the PTO (about 3 to 4 amps each...and most 318 tractors have only the front one fitted) and the headlights. Since these loads are not typically on when the key switch is moved to the RUN position, the key switch contacts only must carry the loads when active -- not switch them. In any event, your modification will help.
Does your tractor have the starter improvement relay added also, or was that solenoid load contributing to the early demise of your last key switch?
Chuck
I eventually traced the problem to a corroded "run" contact on the back of the ignition switch. The old switch showed burn marks around the contact as well. I replaced the contact in the connector block that connects to the back of the switch. My change covers the starter solenoid and all of the other loads as well. Power for the solenoid still flows thru the start position of the ignition switch. I have a B43G engine which has a external solenoid. The P218 has the solenoid on the starter.
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1,641 Posts
Larry,
The external solenoid of the B43G draw a lot of current and a relay for the Start position is a very good investment.
The key switch don't have a spring loaded trigger like a good quality switch.
For this reason every transition to the start position generate a spark for a long period of time because the current began to jump even when the contacts are not connected.
Andre
The external solenoid of the B43G draw a lot of current and a relay for the Start position is a very good investment.
The key switch don't have a spring loaded trigger like a good quality switch.
For this reason every transition to the start position generate a spark for a long period of time because the current began to jump even when the contacts are not connected.
Andre
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1,001 Posts
Hello Larry
I replaced the Ignition switch in my Son in law's 316 and it worked fine for awhile but then began to Just click the starter. I Placed the starter Improvement kit and it Cured the clicking noise and it start's Effortlessly now. Regards, Kurt
I replaced the Ignition switch in my Son in law's 316 and it worked fine for awhile but then began to Just click the starter. I Placed the starter Improvement kit and it Cured the clicking noise and it start's Effortlessly now. Regards, Kurt
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