| Author |
Message |
    
Dan Haakenson
Member
Username: Dhaaken
ND
Registered: 6-2008
Post Number: 57
| | Posted on Sunday, July 25, 2010 - 10:25 am: | 
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I don't have the electrical schematic so I can't trace the wires. There is power to the solenoid, but no power to either fuse. At first the lights would come on, and when I tried to start it, there was a click like a faulty solenoid, so I replaced that. Then the lights quit coming on at all, so I doubt it was that.
I assume a safety switch is likely involved, but which one(s) cut power off completely? It has the rear PTO so there are two PTO switches. The safety switch on the hydrostatic lever is engaged properly.
Thoughts? Ideas?
Dan |
Brad Meehan
Member
Username: Bradm
Ct
Registered: 6-2006
Post Number: 696
| | Posted on Sunday, July 25, 2010 - 10:37 am: |
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There is a circuit breaker that is under the battery tray on the right side that could be the problem. Here is a wiring diagram I stole from another thread. Thanks Chuck.
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Dan Haakenson
Member
Username: Dhaaken
ND
Registered: 6-2008
Post Number: 58
| | Posted on Sunday, July 25, 2010 - 11:01 am: |
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That appears to be it, thank you. For those that might look at this thread, perhaps we can take it a bit farther. I had removed the tractor side of the breaker, and both side of the breaker had power. However, when I connected the tractor side wire, the voltage dropped to zero. So when I first tried to start the 318, the click I heard was the breaker. If I waited long enough for the breaker to cool, the lights came back on, but when I tried to start it, I heard a click which was the breaker opening I assume. Unfortunately I didn't make the mental connection that the breaker was at fault.
Why would the voltage on the tractor side drop to zero when the tractor side wire was connected? There was no spark so it wouldn't appear there was a grounding problem. Second question, what is the purpose of the breaker? Thanks again. Dan |
Brad Meehan
Member
Username: Bradm
Ct
Registered: 6-2006
Post Number: 697
| | Posted on Sunday, July 25, 2010 - 11:35 am: |
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Dan,
I have had a issue were the breaker was not bad but the push on connector was loose on the pin of the breaker. The loose connector caused the breaker to trip because of the high resistance at the connector.
I cut the push on connectors off and crimped on eye connectors threaded a nut on the post then the eye connector then another nut.
The breaker is used so if you have a direct short to ground or overdraw of current somewhere you will not burn up the wiring harness. |
Dan Haakenson
Member
Username: Dhaaken
ND
Registered: 6-2008
Post Number: 59
| | Posted on Sunday, July 25, 2010 - 11:36 am: |
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I spoke too fast. With the new circuit breaker in place, the lights would come on, and the starter would engage, but then the breaker would trip again, and everything would go dead. I assume that means the starter is drawing too much current, or not? It appears changing the starter would required pulling the engine at least partially.
Dan |
Vinnie Hueber
Member
Username: Vinnie110
NY
Registered: 9-2004
Post Number: 1051
| | Posted on Sunday, July 25, 2010 - 12:38 pm: |
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I would want to inspect the wire that runs from the ignition switch to the starter solenoid for shorts before pulling the starter. Also I might want to disconnect the small wire from the solenoid and see what happens when the key is turned to start. Assuming the wiring is good it sounds like the starter solenoid is pulling too much current |
Cliff Harms
Member
Username: Charms
MB
Registered: 5-2005
Post Number: 716
| | Posted on Sunday, July 25, 2010 - 12:52 pm: |
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Dan, the starter itself does not draw power through the breaker. Somewhere else is using too much power or you have a short or the circuit breaker is faulty.
Cliff |
Dan Haakenson
Member
Username: Dhaaken
ND
Registered: 6-2008
Post Number: 60
| | Posted on Sunday, July 25, 2010 - 2:14 pm: |
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Cliff, I should have thought about that as the solenoid pulls power, but the power between the starter and the battery is direct because of the connection the solenoid makes.
Vinnie, but if I have a short in the wire, would it not get hot enough to melt or smoke or something.
How long does it take the circuit breaker to reset? It's been several hours and it still is not reset.
Thanks for your replies. Dan |
Chuck Van Dusen
Member
Username: Chuckv
OR
Registered: 1-2007
Post Number: 3822
| | Posted on Sunday, July 25, 2010 - 2:17 pm: |
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Dan,
The circuit breaker resets in approximately a minute or two...the time you state indicates another issue is involved as well...
Since it does not show in your profile, what year is the 318? There are minor differences with the B versus P series engines, the former has a Bendix starter and separate solenoid whereas the latter has a 'solenoid shift' starter with the solenoid mounded directly to the starter and also serving to engage the pinion with the ring gear as well as provide the high current contact switching.
Here is the wiring diagram for the starting circuit, but as noted by others in this thread, there may be a harness short elsewhere in the wiring that is tripping the breaker.
Note that the power for the solenoid passes through the key switch TWICE and the switch and its mating connector can be a source of symptoms like those you describe. If this is the original switch that came with the tractor, you will be well advised to replace it with a new one. Inspect the mating connector for signs of overheating and corrosion and service as required.
Chuck |
Dan Haakenson
Member
Username: Dhaaken
ND
Registered: 6-2008
Post Number: 61
| | Posted on Sunday, July 25, 2010 - 2:18 pm: |
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The circuit breaker doesn't trip until I engage the starter. That would seem to indicate the culprit would be the solenoid, but I did switch that, although with another used one.
That is, if the short were anywhere else on the tractor, the indicator lights would not even come on, right? Would not the fuses blow first?
Dan |
Dan Haakenson
Member
Username: Dhaaken
ND
Registered: 6-2008
Post Number: 62
| | Posted on Sunday, July 25, 2010 - 2:25 pm: |
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Chuck,
This starter has no solenoid mounted on the starter, the solenoid is mounted under the battery.
The starter switch is five-lug with a sixth lug which is a separate. The other 318 I have has only the 5-lug.
I'll check for mating plug heat as soon as the circuit breaker resets, or is there a way to do that?
Thanks. Dan |
Chuck Van Dusen
Member
Username: Chuckv
OR
Registered: 1-2007
Post Number: 3823
| | Posted on Sunday, July 25, 2010 - 2:26 pm: |
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Dan,
The symptoms you describe are those of a connection going open (or very high resistance) when faced with passing a somewhat large current. This could easily be in the key switch and its mating harness connector, and/or some similar connections (including the push on connectors at the circuit breaker...) The circuit path is getting interrupted at some large current flow, but this would not necessarily be enough to blow the fuse...
All of what you describe sounds like a poor connection somewhere -- did you also check/clean the battery terminals and the engine and frame ground cable connections?
Let us know what you find, and good luck.
Chuck |
Chuck Van Dusen
Member
Username: Chuckv
OR
Registered: 1-2007
Post Number: 3824
| | Posted on Sunday, July 25, 2010 - 2:29 pm: |
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Dan,
I was suggesting a visual inspection of the connector to see if it looked burned or corroded/blackened. You do not have to test for any elevated temperatures during operation...
As I mentioned earlier the circuit breaker only takes a minute to reset, so something else is open in the wiring if it still is not operable after several minutes of time has elapsed.
Chuck |
Dan Haakenson
Member
Username: Dhaaken
ND
Registered: 6-2008
Post Number: 63
| | Posted on Sunday, July 25, 2010 - 4:31 pm: |
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Chuck,
Visual inspection indicated two mating connectors that were badly rusted. When I cleaned them, the circuit breaker works fine. I was using jumper cables to test it, and they were a bit light and started to get hot, but I assume when I get the regular cables hooked up it will be fine. The starter must draw some serious current.
For my edification: Why would an open, interrupted connection keep the breaker from resetting?
I'll reinstall the battery (getting good at that) and see if I can get it started, then report back.
Thanks. Dan |
Chuck Van Dusen
Member
Username: Chuckv
OR
Registered: 1-2007
Post Number: 3825
| | Posted on Sunday, July 25, 2010 - 4:44 pm: |
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Dan,
Glad you found the culprit connections! Yes, the starter motor can draw some substantial amperage -- starter motors are "intermittent duty" devices and will get really hot if you run them too long at a time.
The circuit breaker probably reset in its nominal timeframe, but with an additional open circuit in series with it you could not tell...
Chuck |
Dan Haakenson
Member
Username: Dhaaken
ND
Registered: 6-2008
Post Number: 64
| | Posted on Sunday, July 25, 2010 - 5:37 pm: |
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Chuck,
The 318 turned over just fine and started several times. Then it died. At first, I could get it started again, but it sounded like an ignition issue. Back to where I was before. The switch looks fairly new, but could that still be suspect?
Dan |
Chuck Van Dusen
Member
Username: Chuckv
OR
Registered: 1-2007
Post Number: 3826
| | Posted on Sunday, July 25, 2010 - 6:19 pm: |
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Dan,
In all of the above discussion I see no mention of any measurements with a voltmeter to see where the voltage is being lost/interrupted when the symptoms are present. Does the input side of the 20 amp fuse (the side that connects to the key switch) have voltage present in both the START and RUN positions of the key when the tractor electrical system is 'dead'? If so, does the purple #700 wire to the solenoid have voltage when you turn the key switch to START. If any of these is answered no and you have tested all the safety switches in the wiring in my post 3822 above you may have a bad key switch. Note that the early tractors such as yours do not have the brake switch fitted, and when there is no rear PTO switch there is a jumper between the 720 and 730 purple wires in connector X5...
Chuck |
Dan Haakenson
Member
Username: Dhaaken
ND
Registered: 6-2008
Post Number: 65
| | Posted on Monday, July 26, 2010 - 12:57 pm: |
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I was going out to John Deere anyway so for $18 I picked up the switch. Still no go, so I'll trace down the safety switches next, and see where the power is being interrupted. Thanks. Dan |
Dan Haakenson
Member
Username: Dhaaken
ND
Registered: 6-2008
Post Number: 66
| | Posted on Monday, July 26, 2010 - 6:12 pm: |
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I checked the voltage on the tractor side of the circuit breaker and it would reset as you said, but still no indicator lights, but there was power to the switch.
So I took off the hood latch so I could get better access to the dash. I removed and reinstalled the connectors to the two PTO switches. As I remember the two-pronged connectors with purple wires are the safety switches. Now it appears to be working so back together one more time.
Chuck, is there a point on the tractor where it would be easy to check the continuity of all safety switches, or do they need to be done individually?
Dan |
Chuck Van Dusen
Member
Username: Chuckv
OR
Registered: 1-2007
Post Number: 3829
| | Posted on Monday, July 26, 2010 - 6:32 pm: |
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Dan,
If you look at the circuit in the drawing included in my post 3822 above you will see that the PTO switch(es) and the transmission neutral switch, along with the brake switch if fitted as in the later years, are effectively wired in SERIES -- so the presence of voltage at the purple wire #710 on terminal S2 of the key switch when in the RUN position confirms all of these are working as intended, but the absence of voltage there does not narrow the issue down to the particular one or more faulty switches or wiring.
The seat safety switch (operator present switch...) is "sensed" by the TDCM at X22 pin 9, so that would require a separate measurement/confirmation.
Chuck |
Dan Haakenson
Member
Username: Dhaaken
ND
Registered: 6-2008
Post Number: 67
| | Posted on Monday, July 26, 2010 - 6:43 pm: |
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Found it! I noticed that when I moved the wires around it would work for awhile. I pulled a long blue wire which was going to one of the PTOs, and it was shorting out. It was greasy and dirty so it appears the connection was just enough to trip the circuit breaker, but not enough to make the wire smoke. Live and learn. Thanks Chuck for your astute advice as always. Dan |
