312-8 Starting Issue

[TheMooseIsLoose 6]

I currently have (4) Wheelhorse tractors and i love them all except for electical issues which seem to come up all the time. My 312-8 when i turn the key nothing happens. I put a new starter switch in because it was all corroded and thought there was a polarity issue, also another solunoid and the battery is good, still nothing when i turn the key, if i jump the solunoid it will start, the only thing i didn,t do was clean all the grounds.

Does anyone have an idea as to why this is happining. Thank you for your support.

[gwest_ca-(File Mod) 10,474]

What is the model number of this 312-8? They changed the wiring on many of these.

 

Garry

[ARK 9]

From your post, the tractor is old, machines age but electrics take longer to age and at a point that older age catches up.

 

Catch up regarding grounding: grounding is a cheaper way to distribute the return wire from the device, but age brings rust, weakened joints and this in turn wrecks havoc with returns.

Devices get old and a lack of maintenance especially cleaning and removing oxide as rust hamper operation and increase the normal resistance and inductance making the device draw more current

Batteries age as do the cables, contacts and junction, all the joints need to be open, cleaned and then made tight.

The 312-8 has a simple electrical system but it his easily compromised by not doing regular maintenance.

Regular maintenance need to be done when the machine is 3 years old and every 2-3years.  That means cleaning, removing oxides, opening joints cleaning and securing them back up.  Verifying joints with a multi-meter, verifying alternator  voltage, cleaning light sockets and joints.

 

If not done electro al gremlins will always haunt that machine.

 

Wires age, contacts age, devices age, after checking and testing a light spray of WD40 will keep mater vapour away.  If you use dielectric greases incorrectly you are creating more problems.  But if you spend a warm afternoon every 2-3 years doing the work there is no need for dielectric grease in a routine PM program.

 

Try it once and you will see that the results are very satisfying.  Afraid of electrical work, don't be, Google your questions before hand and remember a 12V DC system is very low voltage but the starters can be higher currents.  It is very easy to kill a 12V DC circuit with any grease, learn how to apply and when before doing it

[TheMooseIsLoose 6]

Model # is 21-12k801 and is a 1985 issue, almost 30 years old but runs great when it runs. The saftey switches for the seat and clutch have been disconected. I'm thinking it must be some kind of grounding issue.

[gwest_ca-(File Mod) 10,474]

Wiring diagram from the operator manual

This model originally had battery ignition and 3 amp unregulated charging system.

Kohler K301S-47812

 

Garry

[tunahead72 2,332]

... the only thing i didn,t do was clean all the grounds ...

Not to be a smart a__, but I would clean all your grounds.  You may get lucky and that will completely solve your starting problem.  And if not, it's an easy and inexpensive thing to do, and will eliminate that as the cause.

 

Good luck, and keep us posted!

[TheMooseIsLoose 6]

Garry, thanks for the wiring diagram & Tunahead i cleaned the grounds but will have to check them again. I have since put this tractor away for the winter and will check in the spring, i don't have the time right now, thanks guys.

[varosd 1,185]

but if you get a snow blade or snow thrower you could use it year round!!

[TheMooseIsLoose 6]

Don, i have a 520H with a snowblower on it so i am all set for that.

[sorekiwi 761]

If the engine cranks when you jump the solenoid then it is unlikely to be a ground that is causing your issue.

 

I would first suspect one of the safety switch's, you stated that the seat and clutch switch's have been bypassed, so the only one left is the PTO switch.

[Wheel-N-It 2,967]

Well you can always temporary up a momentary contact switch so at least its useable this Winter. I would do that before just letting it sit till next Spring.

[motox25 36]

I would check the PTO switch and fuse box. The PTO switch on my 520 failed and it did that same thing.

[TheMooseIsLoose 6]

thanks for the feedback, i will check the PTO switch & fuse box, that makes a lot of sense, thank you.

[jackhammer 544]

If I may , I had a problem with my 312-8 this past spring. just as sorekiwi above said.

My problem was that the PTO arm over the years ,(1990), oval shapped the tower where it passes thru to the pto switch. At that entry point there is a small thin plastic bushing. I replaced the bushing first but didn't solve anything. The pto arm kept dropping down, just a small bit, because of the egg shape hole and would not engage the starter. I fashioned another stiffer and a bit longer bushing to fit into the tower(a plastic air wick dispenser inside sleeve). Reamed it out a bit. Holds the pto arm up and haven't had a problem since..

Rick