Wheel Horse 314-8 will not start

[terc 1]

I have a wheelhorse 314-8 that has no problems until this morning when I tried to start it. It will not turn over or even fire at the sparkplug, also the test lights will not work. I thought this was very strange as this tractor has performed very well for many years. After pulling the battery to check the wiring I discovered the 25amp fuse had blown, so replaced with new one. Still no working test lights. The fuse will blow when you try to start the tractor. I have checked the pto and seat switches which seen to be working properly. Iam hoping the experts here can shed some light on this problem for me

[gwest_ca-(File Mod) 11,256]

The 314-8 was made in 1985 and 1993-2001. Would you happen to have the model number and serial number off the ID decal that may be on the rear fender pan under the left side of the seat? That will lead us to the correct wiring diagram so we are all on the same page.

Also - do you have a test light or multimeter for testing?

Garry

Edited June 26, 2015 by gwest_ca

[terc 1]

Model # 73400   Serial # 3901221

and yes I have both a test light and a multimeter

[gwest_ca-(File Mod) 11,256]

Here are the wiring diagrams.
http://www.wheelhorseforum.com/files/file/2214-tractor-1993-314-8-wiring-detailed-492-4509pdf/

The first thing I would do is look the tractor over real good for any locations that have wire contacting or close to moving shafts or levers and wiring over sharp edges. The steering and attachment lift are two of them. The insulation on the wire will wear away leaving an almost invisible section of the copper exposed = short. It will not likely be detected by feel.  You can only see it. Say this first because once you start working on it you move things around and lose tract of the possible problem locations. I have seen the wire insulation worn flat and in the center of the flat a small line that looked like a thin pencil line. It was bare copper and enough to blow a fuse on the steering shaft.

To save going through a truck load of fuses remove the blown fuse and replace it with a test light or voltmeter. You need to plug into each of the terminals the fuse was in. The test light will come on or a voltmeter will show 12 volts when a load or short is present. I use a small 12 volt electronic chime salvaged from a seat belt warning system from an auto. That way I don't have to watch a tester. When the short is present the tester or alarm is activated because the short is completing the circuit. Problem is any natural load like lights or a relay will also activate the tester or alarm. You have to disable them (unplug) to remove them from the circuit. 


From what you described I can't tell if the problem is in the ignition/accessories or the starter circuits. The 25 amp fuse feeds the ignition switch which powers the 15 amp fuse and it didn't blow so remove the 15 amp fuse and that will eliminate the hourmeter and lights from false triggering the tester or alarm.
Try turning the key to the RUN position and see if that triggers the short. You will need to unplug the relays as they will active the tester. Move the wires around to see if that is it. 
It may only short in the START position. You will need to unplug the relays as they will active the tester. Move the wires around to see if that is it.

You may want to unplug the circuit board for the idiot lights if you have them. The tractor will operate without them so unplugging will reduce the chance of a false tester reading.

A warning. Your ignition is self-powered and it is simply grounded to shut the engine OFF. Do not allow and power into the ignition wire as that will fry the ignition coil. The tractor does control the ignition through a powered relay so it needs to be disconnected to eliminate a false tester activation. 

Let us know what you find or if you have questions.

Garry
 

Edited June 26, 2015 by gwest_ca

[terc 1]

gwest - your warning does concern me alot. how can i prevent power going to the ignition wire. There are 2 I'm assuming they are the powered relay located next to the starter selonid. do these need to be disconnected.

[gwest_ca-(File Mod) 11,256]

You would have to physically jump the wiring from a battery power source to the ignition wire to cause a problem.

Not knowing what the relays are for I would say yes remove them. Just keep track of which one came from where if they are not the same relay. If you compare the wire colors to the relay with those in the diagram you should be able to identify which ones they are. You may end up reinstalling them to find the short if it is beyond the relay, The internal relay coils are enough to activate the tester or alarm so one has to use a different test method if it comes to that.

Garry

[Brian01 481]

Yeah I'm betting you have a bare/bad wire somewhere touching another wire or frame somewhere...look it over with a fine tooth comb.

[terc 1]

thanks to all that replied to my troubles. Turns out that the ignition switch # 103990 that  was ordered online did not work, which added to my confusion. Made a lenghty trip to another Toro/Wheelhorse dealer and after some troubleshooting it was decided to replace the ignition switch with a proper one.
problem solved. So was it the correct switch or just a bad switch,Hmmmmmm only the gremblins know for sure.

[gwest_ca-(File Mod) 11,256]

Here is an original parts list
http://www.wheelhorseforum.com/files/file/2587-tractor-1993-314-8-iplpdf/

The 103990 switch is for battery ignition and you have magneto ignition
The 111216 switch in the parts list has been changed to 103990.
The 116338 switch must be for the magneto ignition.
Have no idea why the battery ignition switch is even listed in the 1993 314-8 manual.

Garry.