I got the P218 in and all hooked up, now I need to know if I did a few things right or not, I removed the old panel mounted solenoid and ran a straight battery cable down to the starter. Also on the starter post is the red wire from the starter improvement gadget. The purple wire to the solenoid terminal went up to the main harness and a non used purple wire was in there and it tested hot with the key to the start position. The old 25 amp circuit breaker remained on the chassis and I hooked this to the battery positive side. Everything cranks and it did start once, even though I have fuel delivery issues now, I can worry about that later, anyway , the spark it weak. Just wondering if I have something wrong or can anyone that has done this conversion put some more insight on this, thanks in advance.
B43G 318 motor swap to P218 electrical help
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Hello Mike
The Purple wire should run from the spade terminal of your solenoid to the Key switch. The Red wire coming off of your 25 amp circuit breaker should go to the Hot Threaded stud of your starter along with the Main hot battery terminal wire held down with the stud Nut Both of these wires go together on your starter. If the Red circuit breaker wire is Not attached with your Hot battery cable wire on the solenoid of the starter the engine will not turn over using the key switch. The spare Purple wire may be for the Rear PTO switch option and it should be run to a connector close to the dash area close to where the front PTO switch connections are & it has a Factory Placed Jumper wire across the Rear PTO Female wire connector if the Tractor does not have the rear PTO Option on it, it's connector is simply sitting there with a Jumper wire placed in it. I hope this helps, Kurt
The Purple wire should run from the spade terminal of your solenoid to the Key switch. The Red wire coming off of your 25 amp circuit breaker should go to the Hot Threaded stud of your starter along with the Main hot battery terminal wire held down with the stud Nut Both of these wires go together on your starter. If the Red circuit breaker wire is Not attached with your Hot battery cable wire on the solenoid of the starter the engine will not turn over using the key switch. The spare Purple wire may be for the Rear PTO switch option and it should be run to a connector close to the dash area close to where the front PTO switch connections are & it has a Factory Placed Jumper wire across the Rear PTO Female wire connector if the Tractor does not have the rear PTO Option on it, it's connector is simply sitting there with a Jumper wire placed in it. I hope this helps, Kurt
ok, that does help some, it seems that I need to jump the positive side of the coil with 12volt, this would tell me the key switch is not working right, other than that I have the tractor starting and running good now. are these known for key switch issues?
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Hello Mike
The later John Deere 318's that had the P-218 in them were well known to be Key switch eaters. It is due to the electric current having to Travel twice through the wiring harness safety switch's before supplying Power to the starter and if there is any slight voltage drop it makes the starter work harder due to the voltage drop. The starter improvement kit is supposed to help this issue. Regards, Kurt
The later John Deere 318's that had the P-218 in them were well known to be Key switch eaters. It is due to the electric current having to Travel twice through the wiring harness safety switch's before supplying Power to the starter and if there is any slight voltage drop it makes the starter work harder due to the voltage drop. The starter improvement kit is supposed to help this issue. Regards, Kurt
Ok, I wondered about that and thought I had heard of that a long time ago. I dont seem to have any power going to my coil +side from the wire coming out of the TDC box. I jumped a wire from the battery to the coil and it started up using the key like normal. (I did try a good key switch off the good 318) all the other stuff seems to work, neutral switch, pto switch (seat switch is wired closed) and all works good and will not start. I think rather than get a new TDC, I could just add a fused switch to the coil and be good to go. comments...
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Mike,
It is very likely NOT the TDCM, but rather the safety interlocks. Here is what is needed to make the coil "hot" on the Onan engines in the 318 tractors:
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When the key is in the RUN position, you should have voltage on the X22 pin 9 of the TDCM connector if the seat is occupied. That allows the ignition to be hot whenever the operator is present, and kills the engine if he should come out of the seat with the ground speed lever engaged or the PTO on. Voltage on pin 9 may be missing if the F2 fuse or holder is bad/intermittent, or there is an open wire in the harness back to the seat switch.
There is a bypass path (not shown entirely above) via pin 7 of the X23 connector -- it will have voltage when the drive lever is in the Neutral slot and the PTO switch(es) are off. Later models also incorporate a parking brake switch which must be closed as well by setting the parking brake.
Are you able to properly crank the engine with the START position of the key switch (only works if the neutral switch is closed, the PTO switches off and the parking brake set...)
Chuck
It is very likely NOT the TDCM, but rather the safety interlocks. Here is what is needed to make the coil "hot" on the Onan engines in the 318 tractors:
When the key is in the RUN position, you should have voltage on the X22 pin 9 of the TDCM connector if the seat is occupied. That allows the ignition to be hot whenever the operator is present, and kills the engine if he should come out of the seat with the ground speed lever engaged or the PTO on. Voltage on pin 9 may be missing if the F2 fuse or holder is bad/intermittent, or there is an open wire in the harness back to the seat switch.
There is a bypass path (not shown entirely above) via pin 7 of the X23 connector -- it will have voltage when the drive lever is in the Neutral slot and the PTO switch(es) are off. Later models also incorporate a parking brake switch which must be closed as well by setting the parking brake.
Are you able to properly crank the engine with the START position of the key switch (only works if the neutral switch is closed, the PTO switches off and the parking brake set...)
Chuck
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Hello Mike
I am Glad that Chuck Van Dusen chimed in here, it was him that helped me work through an electrical issue that I was having on my 1991 John Deere 316 that I was building for my son in law. My issue was that the Previous owner had cut the Red wire that goes from the circuit Breaker down to the Hot battery cable stud on the starter and ran it to the Hot side of the battery instead. I could not get the Onan P-218 to start by Turning it's key switch, Yet by crossing the back of the switch with a screwdriver it would turn over and start. We also found the purple wire unhooked that run's from the Ignition switch to the spade Lug on the starter solenoid. Once I corrected the wiring issues that were wrong it would Turn the engine over by using the Key switch but not every time so I figured it had to be a bad Ignition switch so I got a new one and all is fine now, as the Original one was not working all of the time due to an Internal issue caused by the voltage having to pass through it twice before engaging the starter, which in an Older wiring harness the voltage can easily drop due to Old connection's or corrsion issues at those connections. How I found the circuit breaker wire missing that goes to the starter is I did a Search on this forum for Onan starter wiring diagram which showed me that the circuit breaker wire ran directly from the circuit Breaker down to the Hot Lug on the starter Joining the Hot Battery cable at the same location and that the Purple wire was supposed to go to the male spade terminal on the side of the starter solenoid See The attached Link below of that diagram, it is similar to the one Chuck provided but a Little more clear to me as it shows the starter circut wiring for a Late 316 which has the Onan P-218 engine with the electronic ignition on it which is just about like the same diagram as that for my 318 but mine is a first Year model bing a 1983 and has Point's ignition so the starter's are different as well as some of the wiring harness.
Most Guys that have the later P-218's engine's in their 318's have added a starter Improvement kit in their wiring systems. By doing that it supplies the starter with a full 12 Volt's when the Key switch is Turned to the start position, Rather than to run the electrical current twice through the Tractor's safety switch's which is the function of the T.D.C.M AKA: Black Box. If it were me, I would check all of your safety switch connector's to be sure that there is no corrosion present and Place some Di-Electric Grease on their connector's. There will be a seat safety switch, neutral safety switch at the Hydro lever under the dash panel, and depending on the year of the Tractor a Foot Brake safety switch, as well as a Jumper wire connector for the Rear PTO if there is not one on the Tractor that Purple Jumper wire has to be making a good solid connection. Being that Most of these Tractor's are now 30 Years old or so vibration and corrosion may be present at the connectors. I did find one spade fuse connector Loose so I wedged a screwdriver into the connection making sure it held the fuse solid Making a good connection and my wiring issues have been solved. We will be placing a starter Improvement Kit eventually on the 316 to Make it's ignition switch last longer and allow the Tractor to start easier. I hope this helps, Kurt
[URL="http://ww2.justanswer.com/uploads/motoforge/2012-01-20_012254_316_late.jpg[/IMG]http://ww2.justanswer.com/uploads/motoforge/2012-01-20_012254_316_late.jpg[/URL]
I am Glad that Chuck Van Dusen chimed in here, it was him that helped me work through an electrical issue that I was having on my 1991 John Deere 316 that I was building for my son in law. My issue was that the Previous owner had cut the Red wire that goes from the circuit Breaker down to the Hot battery cable stud on the starter and ran it to the Hot side of the battery instead. I could not get the Onan P-218 to start by Turning it's key switch, Yet by crossing the back of the switch with a screwdriver it would turn over and start. We also found the purple wire unhooked that run's from the Ignition switch to the spade Lug on the starter solenoid. Once I corrected the wiring issues that were wrong it would Turn the engine over by using the Key switch but not every time so I figured it had to be a bad Ignition switch so I got a new one and all is fine now, as the Original one was not working all of the time due to an Internal issue caused by the voltage having to pass through it twice before engaging the starter, which in an Older wiring harness the voltage can easily drop due to Old connection's or corrsion issues at those connections. How I found the circuit breaker wire missing that goes to the starter is I did a Search on this forum for Onan starter wiring diagram which showed me that the circuit breaker wire ran directly from the circuit Breaker down to the Hot Lug on the starter Joining the Hot Battery cable at the same location and that the Purple wire was supposed to go to the male spade terminal on the side of the starter solenoid See The attached Link below of that diagram, it is similar to the one Chuck provided but a Little more clear to me as it shows the starter circut wiring for a Late 316 which has the Onan P-218 engine with the electronic ignition on it which is just about like the same diagram as that for my 318 but mine is a first Year model bing a 1983 and has Point's ignition so the starter's are different as well as some of the wiring harness.
Most Guys that have the later P-218's engine's in their 318's have added a starter Improvement kit in their wiring systems. By doing that it supplies the starter with a full 12 Volt's when the Key switch is Turned to the start position, Rather than to run the electrical current twice through the Tractor's safety switch's which is the function of the T.D.C.M AKA: Black Box. If it were me, I would check all of your safety switch connector's to be sure that there is no corrosion present and Place some Di-Electric Grease on their connector's. There will be a seat safety switch, neutral safety switch at the Hydro lever under the dash panel, and depending on the year of the Tractor a Foot Brake safety switch, as well as a Jumper wire connector for the Rear PTO if there is not one on the Tractor that Purple Jumper wire has to be making a good solid connection. Being that Most of these Tractor's are now 30 Years old or so vibration and corrosion may be present at the connectors. I did find one spade fuse connector Loose so I wedged a screwdriver into the connection making sure it held the fuse solid Making a good connection and my wiring issues have been solved. We will be placing a starter Improvement Kit eventually on the 316 to Make it's ignition switch last longer and allow the Tractor to start easier. I hope this helps, Kurt
[URL="http://ww2.justanswer.com/uploads/motoforge/2012-01-20_012254_316_late.jpg[/IMG]http://ww2.justanswer.com/uploads/motoforge/2012-01-20_012254_316_late.jpg[/URL]
I now believe its in the safety interlock. the neutral switch and pto switch will not allow it to crank when these are activated, but it cranks normally otherwise. the seat switch was jumpered from the PO. I think I might be on my way to a used TDC or just rewiring things to work around it.
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Hello Mike
If the neutral safety switch and PTO swith in the On Position are keeping the engine from turning over, The T.D.C. AKA Black Box is doing it's Job. You may have a brake safety switch as well depending on the year of your Tractor. The 316 that I was Building had a faulty brake safety switch so I jumped it as I do not have one on my 318 and could not see any reason to have it operational on the 316 as the Neutral safety switch is in working order. The brake safety switch is on the Lower right frame rail close to the brake pedal assembly it is easier to see and work on from the bottom of the Tractor. The T.D.C. Black Box seldom goes bad in these Machines it's Primary function is to send Power through the safety switch's twice before allowing the engine to start using the key switch. I would suggest that you replace the seat safety switch and take it from there is it start's and Run's it will not be needing the Black Box replaced. I hope this helps, Kurt
If the neutral safety switch and PTO swith in the On Position are keeping the engine from turning over, The T.D.C. AKA Black Box is doing it's Job. You may have a brake safety switch as well depending on the year of your Tractor. The 316 that I was Building had a faulty brake safety switch so I jumped it as I do not have one on my 318 and could not see any reason to have it operational on the 316 as the Neutral safety switch is in working order. The brake safety switch is on the Lower right frame rail close to the brake pedal assembly it is easier to see and work on from the bottom of the Tractor. The T.D.C. Black Box seldom goes bad in these Machines it's Primary function is to send Power through the safety switch's twice before allowing the engine to start using the key switch. I would suggest that you replace the seat safety switch and take it from there is it start's and Run's it will not be needing the Black Box replaced. I hope this helps, Kurt
I believe that the pto switch is now the culprit, and possibly the TDC is intermittenly having issues. for now, I added a seperate switch to the coil power and the pto until I can get some donor parts to fix it correctly, but it is running really nice now.
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