Ryan C 1 #1 Posted May 19 I've been having some trouble starting my 312-8 (73362). I bought it a few months ago and have only used it a few times. Recently when turning the key over I wasn't getting anything. I brought my battery in for a recharge and everything is ok on that front, and I just replaced my solenoid which seemed to be shot. Battery is reading adequate voltage and continuity on the solenoid is good. I thought that would be the solution but I still wasn't able to start with the ignition. I was able to start the tractor by jumping the solenoid, so I'm guessing its nothing with the starter. I just ordered an ignition switch off Amazon (Rotary #7280), to see if maybe that's the problem. Any other suggestions or easily replaceable parts that might be the issue? It looks like the electrical in this was pretty pieced together when I bought it, so hoping its not wiring. 1 Share this post Link to post Share on other sites
pfrederi 18,547 #2 Posted May 19 Is the PTO disengaged?? If you have a multi meter see if you have 12v at the small solenoid terminal when you turn switch to Start. 1 Share this post Link to post Share on other sites
953 nut 59,165 #3 Posted May 19 Please don't buy any more parts until we find out what is actually wrong, looking at the ignition switch you have ordered I see that it IS NOT correct for your 312.Not all Wheel Horses are wired alike. You ordered one for a battery ignition system and your 312 has a magneto ignition. The correct switch is shown below. This wiring diagram shows all of the components in the START circuit. Check the level of your engine oil, if it is low a relay will stop the starter from operating. Beginning at the left you should check the 25 amp fuse and fuse holder. Check to see if you have voltage at the B terminal of your ignition swatch. With your PTO disengaged and your clutch pedal depressed when you turn the key there should be 12 volts at the small blue wire on the Solenoid. Do these checks and let us know what you find. 3 1 Share this post Link to post Share on other sites
oliver2-44 10,555 #4 Posted May 19 If you have a multimeter check your battery voltage, sitting it should be 12.5-13.5 volts. Before you throw more parts at it verify the battery is good. Take your battery to a Auto Parts store and have them do a Load Test . With a verified good battery go over the wiring, cleaning all connections and coating them with dielectric grease. Especially your black battery ground connection to the frame and engine. A Dremel with a small wire brush, or a steel or brass looking tooth brush works good. Lightly pull on each connector to insure they are a tight connection. Run each wire between 2 fingers feeling for internal breaks. (This also helps you learn the wire routing. Clean the area around each safety switch (seat switch, clutch pedal switch, PTO switch) 1 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,386 #5 Posted May 19 The 73362 calls for this ignition switch 116338. The Rotary 7280 replaces switch 103991. Not sure it will work without changes 1 Share this post Link to post Share on other sites
953 nut 59,165 #6 Posted May 19 16 minutes ago, gwest_ca said: Not sure it will work without changes It will not work without otherwise unnecessary wiring alterations. 1 Share this post Link to post Share on other sites
Lee1977 7,124 #7 Posted May 19 The switch on a 312 is in the lower panel attached with only two screws. If it has been left out side the two screws and panel will get rusty making it hard to start with the switch. My 312 always started with the switch but some times it would take three or four tries. With a couple or rusted bolt connecting between the switch and battery ground they can be hard to start. Clean the rust screws and panels if they are rusted.and make sure the key switch has a good ground. 3 Share this post Link to post Share on other sites
