Joe 77 B100 84 #1 Posted December 20, 2021 I gave a new to me 1977 b100 a tuneup and new batter and turned the key. Nothing. Are there safety switches I should check? I don't have an owners manual. Anyone with a YouTube link with steps to check to problem solve? Total newbie here just learning Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,043 #3 Posted December 20, 2021 Click on the picture in the link Starter circuit for most models controlled by Ignition switch, pto switch, clutch pedal switch with gear transmissions or neutral switch with hydro transmissions. Later single cylinder Kohler engines added a low oil switch. All of these control the starter solenoid in that order. 1 Share this post Link to post Share on other sites
8ntruck 7,004 #4 Posted December 20, 2021 to the forum. Most tractors have a safety switch on the PTO and brake. PTO needs to be off, brake needs to be on. Share this post Link to post Share on other sites
Achto 27,571 #5 Posted December 20, 2021 Did this tractor run before you worked on it? Start at the beginning. 1-check battery voltage. You said it is new but I've gotten a bad one in the past. 2-check to see that you are getting voltage to the "B" terminal on the switch. 3-check to see that you are getting voltage to the small terminal on the starter solenoid when the key is in the start position. 2 Share this post Link to post Share on other sites
SylvanLakeWH 25,557 #6 Posted December 20, 2021 I’d also check the pto lever… make sure it is fully disengaged… Don’t ask me how I would know to check this… And 2 Share this post Link to post Share on other sites
953 nut 55,228 #7 Posted December 20, 2021 As @Achto said we need to look at the simple things first. Are all electrical cables clean and tight including grounds? Have you used jumper cables from another vehicle to be sure the battery isn't the fault? With the PTO OFF and you sitting in the seat with the clutch depressed what are the results? Use an old screw driver or pair of pliers to jump across the large terminals of the solenoid, should turn the starter over. Here is a series of checks to determine what component is causing the starter to fail. Why won’t my starter turn over from the key switch? Lets take a logical step by step inspection of your starter problem. Is your PTO in the ON position, a wheel horse will not start with the PTO on. Have you had the battery load tested at an auto parts store? Have you cleaned and tightened all electrical connections including grounds? Are all fuses good and fuse holders cleaned? If these have all been done, we can check components of the starting system as follows; don’t skip a step or you may miss the problem. Be sure the transmission is in neutral and the parking brake is set. Take a pair of automotive jumper cables and connect the black cable to your battery "-" and a good clean spot on the engine. Now connect the other cable to the large post on the starter and touch the other end to the battery "+" terminal, does the starter turn over? If the starter turns over the battery and starter are good. If it didn't turn over try the same steps with the battery in your car/truck, if that cures the problem then the "good" battery wasn't so good. Presuming the starter turned over move the jumper wire from the starter post to the other end of the wire going to the starter which is one of the large posts on the solenoid. If the starter turns over when the battery is touched by the jumper as before then that cable is good, if not you have found your problem. Presuming the starter turned over move that jumper to the other terminal of the solenoid, connect the other end to the battery and use a small piece of wire to temporarily connect the battery "+" terminal to the small terminal on the solenoid, this should cause the solenoid to close and the starter to turn over. If not, the solenoid is probably the problem. If this was successful remove the large jumper cable and use the small jumper wire to the small terminal of the solenoid, the solenoid should close and the starter turn over. If not the cable to the battery is the problem. Presuming all of these have been successful remove the black jumper wire and repeat the small jumper to small terminal, if the starter turns over the ground is good. If all of these components test good then remove your ignition switch, be sure the transmission is in neutral, parking brake on, clutch depressed and PTO off. Use a small jumper to connect the terminals that were connected to the “B” and “S” terminals of the ignition switch. If the starter turns over then the PTO switch and other safety switches are operating properly and your ignition switch may be bad. 3 1 Share this post Link to post Share on other sites
rjg854 11,361 #8 Posted December 20, 2021 and don't be hesitant about asking questions, there's lots of know-how here, sometimes a picture or 2 will also help a lot to help diagnose your problem. 1 Share this post Link to post Share on other sites
Pullstart 62,870 #9 Posted December 20, 2021 Everyone above seems like they got you on the right track. The B-100 is a pretty sweet rig! No nonsense worker! Share this post Link to post Share on other sites