Pete D 83 #1 Posted April 12, 2023 (edited) My '73 16 HP with an Ark500 FEL just stopped working, (the electric clutch, that is), on it's 1st day of use for me. I'm letting it cool in case there is a thermal overload. What else could be the issue? I was scraping modified 3a to use elsewhere when it went out. It's in neutral, key in proper position, switch on, brake on. Belt is not moving, but pullies turn freely. Thanks in advance! Pete Edited April 12, 2023 by Pete D photo 1 Share this post Link to post Share on other sites
WHX?? 48,803 #2 Posted April 12, 2023 Guessing it has a plug on it connecting it to tractor. Check for 12 volts at the plug when trying to operate it. Check for any fuses & wiring supplying power to it. If that all checks out read through the windings of the clutch for continuity/resistance and report back. I don't believe they have a thermal device. 3 Share this post Link to post Share on other sites
Pete D 83 #3 Posted April 12, 2023 Yeah, it did not work after cooling. I will check when I get home. Share this post Link to post Share on other sites
pfrederi 17,685 #4 Posted April 12, 2023 Does yu r electric PTO Look like this one (no big bolt). Just put 12v into one connector plug grou0nd the other you should her a distinct snap. and a slight movent in the clutch plates. No snap check fro continuity between the two terminal pugs. Probably a bad coil. or if you are lucky one of the wires broke free from the field coil itself and there is a chance you can reconnect it. 2 1 Share this post Link to post Share on other sites
Pete D 83 #5 Posted April 12, 2023 Hoorah, no voltage to the clutch. Troubleshooting has begun. 1 1 Share this post Link to post Share on other sites
Pete D 83 #6 Posted April 12, 2023 Blown fuse. Now I need a fuse and must find the short. 2 Share this post Link to post Share on other sites
pfrederi 17,685 #7 Posted April 12, 2023 Lucky Day!!! Share this post Link to post Share on other sites
Pete D 83 #8 Posted April 12, 2023 (edited) Celebrated too soon. No obvious shorts, but blew my last remaining agc20. Next I will disconnect the plug at the clutch & try it with my last remaining agc5. If that does not blow, then I'm thinking the windings in the clutch are shorted, or the wire pulled loose like @pfrederi suggested. If it does blow, then I guess I will replace the wire running from the fuse to the clutch. I'll be removing the glass fuse holder and converting to blade fuses since the glass ones are getting hard to find, too. Edited April 12, 2023 by Pete D 1 Share this post Link to post Share on other sites
pfrederi 17,685 #9 Posted April 12, 2023 Use your multimeter check the field coil for open or short to ground.... Share this post Link to post Share on other sites
pfrederi 17,685 #10 Posted April 12, 2023 Just tested a good one. 3.7 ohms between the coil wires. INF between each one and a ground. 1 1 Share this post Link to post Share on other sites
Pete D 83 #11 Posted April 12, 2023 3 minutes ago, pfrederi said: Use your multimeter check the field coil for open or short to ground.... Field coil is the coil at the back of the electric clutch, I'm assuming. Yes? Share this post Link to post Share on other sites
pfrederi 17,685 #12 Posted April 12, 2023 Yes just unplug the connector and probe the plug on the coil side Share this post Link to post Share on other sites
Pete D 83 #13 Posted April 12, 2023 Ok, I've got 3.6 between the 2 legs and open from each leg to ground. I had the dash out yesterday while I replaced the choke. Although I see nothing rubbing, I may pull the dash again to double check. It did work for about an hour before it died, however. Share this post Link to post Share on other sites
Pete D 83 #14 Posted April 12, 2023 Hot feed is grounded between the clutch switch and the clutch. It seems I found the culprit 1 2 Share this post Link to post Share on other sites
Pete D 83 #15 Posted April 12, 2023 (edited) Maybe not so simple. Wire is fine (disconnected from clutch switch) It's grounding through the ignition switch @ off, probably normal. I'm going inside to review the wiring schematic. Edited April 12, 2023 by Pete D Share this post Link to post Share on other sites
Pete D 83 #16 Posted April 12, 2023 (edited) Sorry for multiple posts in succession. The schematic for this tractor shows a clutch switch with 4 terminals on the back. Mine has 2. It's a two wire (red & orange) to one leg, and the clutch feed with the inline fuse to the other terminal. Wiring appears to be factory. The switch matches the light switch. EDIT - looking at wrong switch. Doh. Edited April 12, 2023 by Pete D Share this post Link to post Share on other sites
Pete D 83 #17 Posted April 12, 2023 Think I found it. Pinched wire from dash removal. Thank you for your help, guys. I'll report back later after I fix it. I need a LONG extension cord to solder the wire. 1 Share this post Link to post Share on other sites
Pete D 83 #18 Posted April 12, 2023 (edited) OK, so I was officially a dumbass today. Always check the last thing you worked on. I've said that to people many times, and did not heed my own advice. Sorry to waste your time. One positive is that I now know how to test the field coil, with resistance value. Thank you @pfrederi Also, thank you @WHX?? for your reply Edited April 12, 2023 by Pete D 1 2 Share this post Link to post Share on other sites
Onmytractor 6 #19 Posted April 13, 2023 So it was the pinched wire from the dash removal then? I appreciated the back to back posts as each had your next steps in troubleshooting! Excellent read before I hit the hay. 3 Share this post Link to post Share on other sites
Pete D 83 #20 Posted April 13, 2023 Yes, it was. I tried a fuse with the clutch disconnected and the key on. When I flipped the switch, the fuse blew. I cut out the damaged section, soldered, and heat shrunk the wire. I also removed the AGC (glass fuse) holder and soldered in a mini ATC fuse holder since they are what my truck and bikes use. I always have some on hand. Concerning the filth in the photo showing the switch, I intend to go through the whole tractor and clean it. I may decide to paint certain parts to prevent rust and to improve it's looks a bit, too. 3 Share this post Link to post Share on other sites
Pullstart 62,812 #21 Posted April 13, 2023 @Pete D your name looks great in red! Glad you were able to make short work of the fix! 4 Share this post Link to post Share on other sites
Pete D 83 #22 Posted April 13, 2023 @PullstartI like to support useful resources so they remain available. Thank you. 2 Share this post Link to post Share on other sites
WHX?? 48,803 #23 Posted April 13, 2023 19 hours ago, Pete D said: OK, so I was officially a dumbass Welcome to the club! 1 1 Share this post Link to post Share on other sites