MainelyWheelhorse 1,440 #1 Posted June 27 (edited) So, I got to the point where I am trying to start the engine or at least check the electronics in my 78 C-141 project. I have a temporary 220 CCA battery to kick it over which is seeming pretty anemic. However, if the solenoid is jumped the starter slowly turns. I haven’t had any magic smoke and the in-line fuse to the starter is fine. I wired it the same as the schematic below. I’m thinking the battery is the issue but I’m stumped. Thanks! Edited June 27 by MainelyWheelhorse 1 Share this post Link to post Share on other sites
pfrederi 18,628 #2 Posted June 27 You can trust your mother not your ground.... (or a weak battery) 3 3 Share this post Link to post Share on other sites
rmaynard 16,289 #3 Posted June 27 220 cca is pretty anemic to turn over a K321. At least charge it over night before trying again. 4 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,437 #4 Posted June 27 Have a voltmeter you can use to test the battery voltage? A good battery will not go much below 12 volts if at all when cranking the starter. That is called a load test. 5 Share this post Link to post Share on other sites
MainelyWheelhorse 1,440 #5 Posted June 27 @gwest_ca @rmaynard I have the battery on a charger, and the display on the charger says it’s been putting out around 12-13amps. @pfrederi I’ll check the ground too. I have it set up like the 312 and 308. The ground to the battery is bolted on to the right side of the tower. It is a bit rusty though so it may not be a great connection. Thanks! 1 Share this post Link to post Share on other sites
953 nut 59,734 #6 Posted June 27 1 hour ago, MainelyWheelhorse said: The ground to the battery is bolted on to the right side of the tower. It is a bit rusty though so it may not be a great connection. BINGO Ground the battery "-" directly to the engine block, rust is not a good conductor of electricity. 4 Share this post Link to post Share on other sites
Handy Don 13,969 #7 Posted June 28 3 hours ago, MainelyWheelhorse said: The ground to the battery is bolted on to the right side of the tower. It is a bit rusty though so it may not be a great connection. Somehow those electrons have to get from the wire, to the tower, and then all the way to the negative terminal on the battery, Make sure the connections are clean! But don’t forget that there must also be clean paths for those electrons from the negative battery terminal to the engine block and any other grounded stuff. 2 Share this post Link to post Share on other sites
Achto 29,349 #8 Posted June 28 11 hours ago, 953 nut said: Ground the battery "-" directly to the engine block This is always the best. 2 Share this post Link to post Share on other sites
MainelyWheelhorse 1,440 #9 Posted July 3 UPDATE: I went back and looked at @953 nut’s schematic. I swapped the starter wire to the positive terminal on the solenoid, and put the 30A fuse on the Battery wire. Now it wants to start continuously if the positive wire is connected to the battery. And that is with the key off. I suspect the solenoid needs a ground. I hope the key switch isn’t bad as it’s brand new. Thanks for the help! Share this post Link to post Share on other sites
953 nut 59,734 #10 Posted July 3 Are you using a 103 990 ignition switch? The wire with the 30 amp fuse will run from the battery + of the solenoid to the B terminal of the ignition switch. They do not get connected to each other. Share this post Link to post Share on other sites
MainelyWheelhorse 1,440 #11 Posted July 4 12 minutes ago, 953 nut said: Are you using a 103 990 ignition switch? The wire with the 30 amp fuse will run from the battery + of the solenoid to the B terminal of the ignition switch. They do not get connected to each other. @953 nut Yes, I am using a 103 990 key switch. The solenoid I have now has the two large + and - poles and one small tab on top on the left. I do have another Solenoid like the one in the picture. I'm not sure if its good though. Now that you posted this it would make sense that the solenoid I have now has no direct way of grounding. Since it only has 3 poles. I think I'll swap it over. to the one thats like the one in the picture tomorrow. Thanks for all the help this has been a learning experience but a good one. Share this post Link to post Share on other sites
pfrederi 18,628 #12 Posted July 4 The solenoids with two big terminals and only one small tab are grounded through their metal mounting bracket. Make sure it has clean paint free contact with the tractor 4 Share this post Link to post Share on other sites
MainelyWheelhorse 1,440 #13 Posted July 6 I think I got it! I tried another solenoid that didn’t work so I went back with some assistance from my father. I reviewed @953 nut s schematic piece by piece and it turned over by the key! Success! A little buttoning up before work tomorrow and I’ll see if it moves for a ride. 😎 2 1 Share this post Link to post Share on other sites
MainelyWheelhorse 1,440 #14 Posted July 11 (edited) IMG_1759.mov After a few setbacks since the Saturday post, My father and I got it to run and drive last night. It ran like a top with no issues. Edited July 12 by MainelyWheelhorse 1 1 Share this post Link to post Share on other sites
