mikemc53 10 #1 Posted September 11, 2021 This one is odd to me but maybe to someone else there's an obvious issue. 1978 C-81 that I've had for about 15 years. Always runs and has had very few problems. About a week ago I was cutting the grass and out of nowhere it stalled - almost exactly like it does when you run out of gas. I had just filled the tank but checked anyway and it was good. Started right back up, cut for awhile, then did the same thing three more times that day. Stall out and start right back up without any excess cranking. So I am thinking fuel delivery issue of some kind which had me go through the filter, fuel pump (mechanical type), gas, carb, etc.. Everything cleaned up and good to go. Cutting today and the same thing...one time. Stall and start right back up. Cut a bit more and it stalled and then...nothing. No start, no crank, no sound of any kind, just dead. Checked the battery and I'm getting about 12.6 to 12.7 volts, which should be at least enough to get something. Checked a bunch of connections and couldn't find anything at all, except there was one wire that had come right out of the connector at the regulator. Got that put back in and still, nothing. So now I don't think it's a fuel delivery issue, necessarily. It seems more like electrical but I don't know what could cause it to stall. When I bought it the previous owner had disconnected the seat safety switch but there are actually no wires connected to the terminals at all so I can't see it being the safety switch. Thoughts? Share this post Link to post Share on other sites
8ntruck 7,021 #2 Posted September 11, 2021 If the previous owner disconnected the seat safety switch, he probably had to connect the two wires that used to connect to the switch together to make the tractor run. Maybe the connection between those wires has come apart. Take a look under the sheet metal between the dash and seat for a couple of disconnected wires. There is probably a wiring diagram for your tractor somewhere in the manuals section of the forum. Somebody who is more computer literate than I might come along and post a link to the wiring diagram. Good luck. 2 Share this post Link to post Share on other sites
squonk 41,162 #3 Posted September 11, 2021 Does this tractor have an ammeter? If so check that and it's connections. 3 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,050 #4 Posted September 11, 2021 The seat switch normally powers the ignition when the pto is ON but that has no effect on the starter circuit. 1 1 Share this post Link to post Share on other sites
8ntruck 7,021 #5 Posted September 12, 2021 Might want to check the safety switch on the clutch/brake pedal. It won't shut the tractor off, but if the switch won't close when the pedal is depressed, the engine will not crank. Share this post Link to post Share on other sites
Pullstart 62,918 #6 Posted September 12, 2021 A simple volt meter and following the power will surely help on this one. Before the completely dead part of the story, I was thinking possible plugged gas cap vent, but I agree that it’s an electrical gremlin somewhere. 1 Share this post Link to post Share on other sites
mikemc53 10 #7 Posted September 12, 2021 Well, I was going to get on here a few hours ago and say that I had found it but... Anyway, I took off the back cover (over the gas tank/rear end) so that I could take a look at the wiring that was jumpered to avoid the seat safety switch. After cleaning up the area I stripped all the tape off the wires to check for any cracks or exposed wires. Couldn't get anything at first but when I pulled a small wire harness out from under a holder that it shared with the gas line I saw the slightest piece of bare wire. After cleaning it and re-taping I tried the key and it turned over perfectly. I thought maybe I had found it. I jogged the starter 8-10 times and it worked every time. I repacked all the wires and put the cover and seat back on. When I went to start it it cranked and then died before it started (probably cranked for only two seconds). After that, nothing again. Took the seat and cover off and started jiggling the harness. At first nothing but when I pushed the harness back and forth it started right up. As it was running I kept moving the harness and once in awhile it would sputter and the ammeter would crazy. I followed where the harness went through the frame toward the dash area and when I wiggled the harness at the ignition I saw one of the leads spark a bit (right at the terminal block) and the sputtering started along with the crazy ammeter. Now I can likely clear up the terminal block wire issue (it's the orange one) but I don't know if the crazy ammeter is telling me I have a wiring/connection issue, like at the terminal block, or that the ammeter itself is bad. I wish I was better at the electrical stuff (mechanical too because, basically, I am a hack) so that I would know where to go from here but I really don't know if a bad ammeter can cause any of these issues. Share this post Link to post Share on other sites
squonk 41,162 #8 Posted September 12, 2021 The ammeter is going to jump around with an electrical connection coming and going. Share this post Link to post Share on other sites
AMC RULES 37,132 #9 Posted September 12, 2021 Sounds like you need to download your wiring diagram and fab up a new wiring harness for your tractor. Share this post Link to post Share on other sites
