Kelsey 91 #1 Posted April 28, 2022 I replaced 310-8 starter solenoid last week. I must have crossed a wire because as I started up the tractor there was a small spark or two behind the instrument panel. I took the solenoid back off and rechecked the wiring and I had something crossed. Next, I put everything back together and the tractor started right up, and it ran for more than a hour with out any problem. Also, I used the WHForum for help on the topic of 312-8 solenoid. Tonight the 3Ten started right up and I backed it up. The motor shut off and the starter was cranking. I put the key in the off position and pulled it out. The starter kept on cranking for a few minutes until I disconnected the negative battery terminal. After a few minutes of me shaking like a leaf, I touched the negative battery cable to the battery with insulated pliers. The starter started cranking all over again with out the key in the ignition. All concise answers would be GREATLY appreciated. Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,072 #2 Posted April 28, 2022 If you remove the small wire from the starter solenoid the starter should not run. If it does the solenoid contacts have welded themselves together. The small wire to the solenoid should only have power when the clutch pedal is down and the ignition key in start position. The start circuit has it's own diagram in the above file that you can download. 2 Share this post Link to post Share on other sites
Kelsey 91 #3 Posted April 29, 2022 Then, it's safe to assume that the solenoid is junk now because of the cross wiring. I ordered another solenoid from Amazon and it'll be here Saturday afternoon. I can't do any- thing tonight as per your advisement. 1 Share this post Link to post Share on other sites
953 nut 55,394 #4 Posted April 29, 2022 here is a pictorial of solenoid wiring. 1 Share this post Link to post Share on other sites
Kelsey 91 #5 Posted April 29, 2022 Thinking back on the swap out of the old solenoid, there was a black (-) wire on the LEFT side of the solenoid. Behind the solenoid plate, there was a wire w/ round wire connector that the hold down bolt went through to fastened to the tractor. And the red (+) went the the right side of the solenoid. Because of the bad light condition, I connected the smaller (+) spade connector on the wrong side. Same went for the (-) spade connector. Again, when I saw a few sparks fly, I shut off the tractor and called it a day. The next morning, I read about the the thread about 312-8 having a solenoid problem. Afterwards, I took the ground spade connector and placed it on the correct lead. Along with the positive spade connector. The tractor started up and ran fine for an hour or so. I shut the tractor off a few times to check it out. My questions are, why did the tractor run fine in the first place? what caused the tractor to shut off? What caused the alleged fusing/welding solenoid contacts? Thanks everyone! Share this post Link to post Share on other sites
squonk 41,171 #6 Posted April 29, 2022 I would look at the wiring at the switch and the switch itself. You may have melted something in there causing the engine to shut down and the solenoid to stay engaged. The switch contacts are pretty puny . 2 1 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,072 #7 Posted April 29, 2022 Do you still have the terminal holder at the ignition switch? I have never liked the individual terminals at the back of the switch as they are vulnerable to shorting to another close terminal. Best to get a replacement wire holder and use Packard terminals as illustrated here Share this post Link to post Share on other sites
8ntruck 7,034 #8 Posted April 29, 2022 I'll add that Packard terminals are available at NAPA stores. Share this post Link to post Share on other sites
Kelsey 91 #9 Posted April 29, 2022 (edited) 9 hours ago, gwest_ca said: Do you still have the terminal holder at the ignition switch? I have never liked the individual terminals at the back of the switch as they are vulnerable to shorting to another close terminal. Best to get a replacement wire holder and use Packard terminals as illustrated here There's a plug unit that houses 5 connectors that plug into the back of the ignition switch along with a separate plug. Edited April 29, 2022 by Kelsey Share this post Link to post Share on other sites
Kelsey 91 #10 Posted April 29, 2022 I just swapped out the ignition switch from another WH tractor. And I barely touched the (-) lead from the frame to the (-) battery post (with the ignition switch in the off position) and the starter started to whine. Share this post Link to post Share on other sites
953 nut 55,394 #11 Posted April 30, 2022 2 hours ago, Kelsey said: I just swapped out the ignition switch from another WH tractor. And I barely touched the (-) lead from the frame to the (-) battery post (with the ignition switch in the off position) and the starter started to whine. Not all Wheel Horses are wired alike! Use the information @gwest_ca has given you to get out of this problem. 2 Share this post Link to post Share on other sites
Kelsey 91 #12 Posted May 2, 2022 Update: I used the info that was provided by gwest and looked at the ignition switch for any problems. Everything looked good to the best of my ability. I replaced the solenoid and the tractor ran fine for another mowing session. Thank you to everyone for their suggestions and help. Kelsey 1 Share this post Link to post Share on other sites
mike avad 41 #13 Posted July 29 (edited) I went to the auto parts store today and order one with just one plug at the bottom of the solenoid 1976 B-80 just like the one that on there now Edited July 29 by mike avad mis spelling Share this post Link to post Share on other sites