bigfkd22 11 #1 Posted September 12, 2013 My 520xi's battery light is on. It comes on and stays on. I have hooked up my multimeter at the pink wire (b+) on the harness that connects to the electronics module and am getting 12.5 volts when I turn the key and have just the lights on. When I start it it goes down to 10.5 for a second then back up to 13 it stays at about 14 at full throttle but the light never goes out. My battery is good and I double checked by swapping another tractors battery just to be sure and it has the same issue. Also if I unplug the harness that goes into the module the light goes out but if I plug it in while running the light comes on immediately. I have checked the voltage at the battery posts as well as the stator and rectifier they all seem to be working. My battery is charging as well. I have the demystification manual, service and operators manuals but they don't address this issue. I have looked at replacement modules but they are 175.00(94-7612)!! So other than lighting up the battery light when the voltage is low or high what else does the module do? What else do I need to check? Could it be something else? Thanks Share this post Link to post Share on other sites
RMCIII 838 #2 Posted September 12, 2013 Troubleshooting 101: When the light first came on, what was the GT doing? Example-mowing, nothing, just started it and it stayed on, ect.? Share this post Link to post Share on other sites
bigfkd22 11 #3 Posted September 12, 2013 When starting comes in and stays on. Share this post Link to post Share on other sites
RMCIII 838 #4 Posted September 12, 2013 This is just for my curiosity... Are you sure you do not have a bar wire someplace that is gounding out causing it to come on? Share this post Link to post Share on other sites
bigfkd22 11 #5 Posted September 12, 2013 No I'm not sure. How could I check? The battery light comes on through a voltage comparator built into the module that has a harness that attaches to it. If u have any ideas let me know and thanks! Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,485 #6 Posted September 12, 2013 What is the model and serial number of this tractor. Looked at one schematic and the battery light is controlled by one terminal on the 6-terminal voltage regulator. Garry Share this post Link to post Share on other sites
bigfkd22 11 #7 Posted September 12, 2013 1998 520xi 73540. Share this post Link to post Share on other sites
shallowwatersailor 3,213 #8 Posted September 12, 2013 The module only indicates low voltage. Check what voltage you have at the battery before starting the tractor and then after. If you have 13.8 volts with it running, it is probably a bad module. I don't think that it will affect anything and only be an annoyance. I would rather have an ammeter on the dash like the older WH. But before condemning it, make sure that all of your connections are good. There is a used module on _bay right now. My 1998 518xi has that same module. For 2000 (maybe 1999 as well), the module was changed to only three wires and about 1/3 the size. When I got my 2000 520xi last month, the light was on but I haven't had a chance to work on it. The battery gets charged with it running though. Check for the 265 H Battery Light post in Electrical on troubleshooting the three wire module. It may be similar in operation. I need to learn how to attach a thread! Share this post Link to post Share on other sites
mdtoro 2 #9 Posted April 21, 2014 Looks like I have the same problem. Anyone resolve this issue yet? Wiring or the regulator? My battery is charging just fine. Share this post Link to post Share on other sites
