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Discussion Starter · #1 ·
Trouble shooting a " no crank " condition
`93 4020PS pin # 14184109
New battery 12.7 V
Figured I would investigate the ignition switch / safety switches and wiring this evening, looking at the schematic from Ingersoll.com
Diagram shows and lists as "quantity required"
2 seat switches ( (C37298)
3 switches at travel lever (C30275)
2 PTO switch (C37399)
A cursory examination has revealed one VISIBLE seat switch and I have yet to look at the PTO or neutral switches.

Why all the redundant switches ? or.. am I interpreting this all wrong ?
Admittedly electricity is my worst subject.

Thanks for your input
 

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10K and Climbin!
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Here's a typical (Cub) wiring diagram..

http://www.onlycubcadets.net/forum/showthread.php?t=22

Follow the STARTcircuit from the Ign sw. until it ends @ the solenoid.. The brown wire on the solenoid is the wire that makes the solenoid activate and connects the two big red wires.. Try to jump between the battery side large wire and thie brown wire and it should turn (key off & in neutral for your safety!) If the starter turns your problem is upstream from that point. Use a 12V test leght and trace the circuit with the key turned to start and you will find the problem. (If the starter doesn't crank check your battery/frame connections (Ground's TOO!) and retry.. If still no go the solenoid or starter is the trouble or the engine is siezed.. :goodl:
 

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Trouble shooting a " no crank " condition
`93 4020PS pin # 14184109
New battery 12.7 V
Figured I would investigate the ignition switch / safety switches and wiring this evening, looking at the schematic from Ingersoll.com
Diagram shows and lists as "quantity required"
2 seat switches ( (C37298)
3 switches at travel lever (C30275)
2 PTO switch (C37399)
A cursory examination has revealed one VISIBLE seat switch and I have yet to look at the PTO or neutral switches.

Why all the redundant switches ? or.. am I interpreting this all wrong ?
Admittedly electricity is my worst subject.

Thanks for your input
dual pole switches. 2 switches in parallel in the same package. Typical when you want to isolate and control two circuits. I'm not familiar with the switches on your tractor, but as an example on your truck maybe you want to actuate the brake lights and kill the cruise control when you depress the brake pedal.
 

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Ingersoll Dealer
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Do you have a hydraulic PTO on this tractor? Mounted in front of the operator and between your legs, next to the shifter. If not, you will not have those switches. If so, the PTO must be completely in neutral to allow the engine to crank (1 swtich) or for the engine to keep running (2nd switch) if you are not in the seat.

You will only have 1 seat switch, unless you also have the remote coupler package for the hydraulic PTO. The remote allows you to run the engine, to operate things like the log splitter, while you are not sitting in the seat.

The seat switch allows the engine to keep running while everything else is working, as long as you are in the seat. It should not prevent the engine from cranking, if I recall correctly.

The 3 travel switches are as follows: 1 controls the neutral light, 1 will shut the engine off if you get out of the seat (switch) while the tractor is out of neutral, 1 prevents the engine from cranking if out of neutral.

These are also interlocked with the PTO circuit, which will prevent the engine from cranking if engaged and shut the engine off if you get out of the seat while the PTO is turned on.

Hope that helps ... you pretty much have to step through bit by bit checking continuity to find the offending item.

All that said, will it crank if you jumper the solenoid (SAFETY: ensure neutral and PTOs off!)? If so, it is in the tractor wiring, no the starter/engine

Brian
 

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TWO KEY WORDS - "If equipped".

In other words, your tractor may not have all the switches shown.


But let's get beyond that and take a good look at the wiring diagram.. There are 2 wires going to the starter. One is the heavy lead AKA "battery cable" and the other is wire that is putting power to the solenoid to engage the starter.

So, how about we begin by making sure the starter and solenoid are OK? Use an old screwdriver to "short" between the big lug on the starter that takes the battery cable and the small terminal that needs 12 volts to make the solenoid kick in. If the starter spins the engine, we've now taken that item off the "suspect list".

The next thing to wonder about is whether the ignition switch is getting 12 volts to it. Do the warning lamps light up? If so, then we don't have a fuse problem and power is getting to the ignition switch. How about the headlights? Do they work off the ignition switch on that model you have? If they are working, then you are definitely getting power to that switch.

The most likely culprit is the dashboard mounted PTO switch and I would suspect the molded connector that the switch plugs into because the electric PTO draws high current all the time it is on. The connectors have a tendency to melt and also corrode... so look there first. The other molded connector of interest is the one that the ignition switch plugs into.

Just so you know, the wiring circuit for the starter is quite simple. Power leaves the "S" terminal of the ignition switch when the key is twisted to START. The power travels to the dash mounted PTO switch and passes through that switch IF the switch is turned OFF. It then goes to the hydraulic PTO switch on the left where the "15" is pointing at. From there, the power heads to the middle switch of the 3 "travel lever" switches before heading directly to the starter solenoid.

Obviously, the hydraulic PTO lever must be disengaged and it must be mechanically operating this switch. The same holds true with the travel lever. If an actuating lever has broken off or is stuck or bent, then the switch won't work. A test light or multi-meter will allow you to track the voltage leaving the key switch providing someone is hold the key to the START position for you. Having a color-coded wiring harness helps but it appears that Ingersoll cut costs by using black wires everywhere.

Print the diagram out and use a red pencil to highlight the wire path leaving the starter and going through the 3 switches to reach the ignition switch. If you do that, it will make sense to you and also make it easier to trace on the tractor. But as I said.....go for the PTO switch/connector first.
 

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Discussion Starter · #6 ·
Thnak you Brian & Castoff.
1. Tractor DOES have rear PTO.
2. There is no power to the solenoid actuating wire when "keyed". this means I`ll need to follow Castoffs path
3. Starter will NOT operate when jumped, have a spare starter. will investigate. Can it be R&R`d with the engine in place ?
4. Neutral light comes "ON"
5. Head and tail lamps all work
6. Printed the diagram yesterday and tried to make sense of it. The TRACTOR has color coded wires, unfortunately the schematic does not.
7. The seven switches for what I perceived as 3 functions was bending my mind.
Thank you both for the clarification.
 

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Discussion Starter · #8 ·
Electrical solved, bad connection at dash mounted PTO switch. Will begin a new thread seeking advice for the next chapter.
Thanks again !
 
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