snowhound 106 #1 Posted October 29, 2019 I've been stumbling around the electrical of a 414-8 trying to find out what is draining the battery when it isn't being used. Today I put the positive lead of my tester on the starter post and the negative lead to the negative post of the battery and got a reading of 10 volts can anyone tell me why this is happening? The negative battery cable was disconnected. The only thing I can think of is a bad starter solenoid. Thanks in advance for your reply, 1 Share this post Link to post Share on other sites
Macwrench 133 #2 Posted October 29, 2019 11 minutes ago, snowhound said: I've been stumbling around the electrical of a 414-8 trying to find out what is draining the battery when it isn't being used. Today I put the positive lead of my tester on the starter post and the negative lead to the negative post of the battery and got a reading of 10 volts can anyone tell me why this is happening? The negative battery cable was disconnected. The only thing I can think of is a bad starter solenoid. Thanks in advance for your reply, You may have nailed it. Share this post Link to post Share on other sites
953 nut 60,724 #3 Posted October 29, 2019 Could be a wire terminal with some corrosion on it that is forming a path from the battery hot wire to a ground wire in the same connector. Here is a thought provoking explanation I saved from a post on here done by @Save Old Iron. Think about it - if you forced a sudden surge of lets say 35 amps thru a 30 amp fuse - the fuse internal element slowly "melts" - usually within a few seconds - you see a melted wire in the fuse body and the fuse body and leads remain looking like they originally did ( give or take a little). If you dead shorted the battery thru the fuse to the chassis, you may blacken the inside of the fuse but the fusible element melts long before you have a chance to cook the entire fuse body like in your picture. Same idea for the white plastic engine harness connector - the brown discoloration is from cooked plastic - where is the heat coming from ?? The "Molex" style connectors used in this tractor series are in a harsh, corrosive environment. Vibration causes the connections to loosen - corrosion starts within the metal terminals and a voltage drop develops across the corrosion. If you have a 10 amp current flowing across a 1 ohm resistance (contact corrosion) the electronics formula to calculate power = current squared times resistance so 10 amps x 10amps x 1 ohm resistance = 100 watts !! 100 watts of connector heating is the same as laying a 100 watt soldering iron on the connector. 1 Share this post Link to post Share on other sites
WHX?? 52,093 #4 Posted October 30, 2019 Man I miss Old Iron.... 4 1 Share this post Link to post Share on other sites
Guest 88vic #5 Posted October 30, 2019 I would ohm test the voltage regulator and charging stator. I have seen stators short to ground, slowly, it wont necessarily blow the fuse but will drain the battery. Same with voltage regulator. Share this post Link to post Share on other sites
lynnmor 7,905 #6 Posted October 30, 2019 27 minutes ago, WHEELHORSEFAN*16 said: I would ohm test the voltage regulator and charging stator. I have seen stators short to ground, slowly, it wont necessarily blow the fuse but will drain the battery. Same with voltage regulator. Yes, so disconnect the regulator and see if you still have a drain. Share this post Link to post Share on other sites
tunahead72 2,555 #7 Posted October 30, 2019 3 hours ago, WHX24 said: Man I miss Old Iron.... Really. 1 Share this post Link to post Share on other sites
N875ED 98 #8 Posted October 30, 2019 How about putting an ammeter on the battery terminal to absolutely confirm current flow when everything has been switched off? A good old Harbor Freight freebie meter will work for indicating "tramp" current flows like this. Then, start pulling connectors apart to determine when/if the current flow stops...from there (with a circuit diagram), finding the culprit should be straightforward. Of course, it the initial test indicates zero current with everything off, the it's just a self-discharging (dead) battery. 2 Share this post Link to post Share on other sites
snowhound 106 #9 Posted November 1, 2019 On 10/29/2019 at 8:42 PM, lynnmor said: Yes, so disconnect the regulator and see if you still have a drain. I assume that by regulator you mean the rectifier but my motor is a M14S-601524 and doesn't have a rectifier or at least I can't find one on the motor or on the wiring diagram for a 1987 414. I'm sorry if what I'm asking seems to be something that is common knowledge but my electrical knowledge is that of a novice and I do appreciate all the help I getting. Share this post Link to post Share on other sites
lynnmor 7,905 #10 Posted November 1, 2019 1 hour ago, snowhound said: I assume that by regulator you mean the rectifier but my motor is a M14S-601524 and doesn't have a rectifier or at least I can't find one on the motor or on the wiring diagram for a 1987 414. I'm sorry if what I'm asking seems to be something that is common knowledge but my electrical knowledge is that of a novice and I do appreciate all the help I getting. You may have only a diode. I looked at several diagrams and found conflicting information. If you test a diode, it should have continuity in only one direction. A crude way to test for a load when there should be none, is to take the smallest light bulb you can find and put the center contact on a battery post while touching the base with the cable just removed. If the light glows, there is a short or a load that didn't disconnect. Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,561 #11 Posted November 1, 2019 On 10/29/2019 at 7:27 PM, snowhound said: I've been stumbling around the electrical of a 414-8 trying to find out what is draining the battery when it isn't being used. Today I put the positive lead of my tester on the starter post and the negative lead to the negative post of the battery and got a reading of 10 volts can anyone tell me why this is happening? The negative battery cable was disconnected. The only thing I can think of is a bad starter solenoid. Thanks in advance for your reply, When you say you put the positive lead on the starter post do you mean the one on the starter motor or one of the large solenoid posts and if so which post? The one to the battery or the starter? Trying to picture what is happening. You do not have a voltage regulator. A sure way to tell is if the engine has to run for the lights to work because the lights are powered directly by a separate flywheel stator/alternator. Garry Share this post Link to post Share on other sites
953 nut 60,724 #12 Posted November 1, 2019 Have you taken the battery to an auto parts store to have it load tested? Have you cleaned and tightened ALL electrical connections? If you disconnect the wiring terminal to the engine it will remove all sources of electrical leakage to the engine. If the battery is good and it looses charge with the engine unplugged then it is not the charging system. 1 Share this post Link to post Share on other sites
pfrederi 18,775 #13 Posted November 2, 2019 You can do a "sort of" load test right on the tractor.. Hook up your multimeter directly to the battery. if it is fully charged you should get 12.6 volts. Pull the spark plug wire and start cranking the engine, voltage will drop but not below 9 volts. (Crank for 35-45 seconds) If it drops much below 9 volts or it won't crank that long ...new battery time (or at least a real load test) 1 Share this post Link to post Share on other sites
snowhound 106 #14 Posted November 3, 2019 I have cleaned all connections I can find and have used two batteries. Also, with the negative battery cable removed the battery doesn't drain Share this post Link to post Share on other sites
