Fordiesel69 271 #1 Posted May 14, 2014 (edited) Whenever the battery is connected, the light is on. Key position makes no difference. It is killing the battery over a periode of time. Any ideas where to start. Edited May 14, 2014 by Fordiesel69 Share this post Link to post Share on other sites
Ed Kennell 42,232 #2 Posted May 14, 2014 (edited) Do you have the schematic for your tractor ? Edited May 14, 2014 by ekennell Share this post Link to post Share on other sites
Fordiesel69 271 #3 Posted May 15, 2014 No. None of the literature came with it. Share this post Link to post Share on other sites
Save Old Iron 1,571 #4 Posted May 15, 2014 (edited) usually the parking brake switch wiring is simple - parking brake mechanics are locked and engage the sensor switch -the switch contacts close and send 12 volts to the yellow wire on the indicator pcb 12 volts on the yellow wire signals the indicator pcb to light the parking brake light so 1) your switch is defective and always closed or 2) yellow wire to the indicator pcb is mis-wired to 12 volts somehow 3) pcb is defective or covered in conductive grass / water / grease mixture - falsely triggering the indicator board. check for 12 volts at the indicator pcb yellow wire - it should not be there when the parking brake is release - if it is, remove the wire connector from the parking switch and see if the indicator goes out Edited May 15, 2014 by Save Old Iron 1 Share this post Link to post Share on other sites
Ed Kennell 42,232 #5 Posted May 15, 2014 No. None of the literature came with it. If you go to the manuals area ,electrical section , and search for your 312-8, you should find the schematic. It's a great help in finding and solving problems. That little smoking squirrel will solve your problem without a schematic ......he has all of them memorized. Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,532 #6 Posted May 15, 2014 If you go to the manuals area ,electrical section , and search for your 312-8, you should find the schematic. It's a great help in finding and solving problems. That little smoking squirrel will solve your problem without a schematic ......he has all of them memorized. Actually most of the electrical diagrams are in the tractors section because the majority of the operator manuals contain a wiring diagram. Saves having to upload them to two locations. Do a search using the tractor's model number and hopefully they come up in the results. After they show up change the sort order to "Title" at the top of the page then change to "Ascending" order. Garry Share this post Link to post Share on other sites
Fordiesel69 271 #7 Posted May 16, 2014 I removed the plug from the brake switch and it is still on. Will check 12v to yellow wire. If there is 12v present, I have a wiring short, if there is not 12v present, then that means the board is bad? Would that be correct? Share this post Link to post Share on other sites
Save Old Iron 1,571 #8 Posted May 16, 2014 yes - correct if you have 12 volts on the yellow wire @ the connector of the indicator pcb - you may have a short to 12 volts thru the yellow wire the only way the indicator should turn on is if it yellow wire has 12 volts coming to it from the switch if the light stays on w/o 12 volts on yellow, the transistor drivers on the indicator pcb are probably shorted ( a 25 cent fix if you can locate the right transistor on the circuit board). Share this post Link to post Share on other sites
km3h 543 #9 Posted May 20, 2014 (edited) Have you looked at the switch yet. There may be something holding it closed. I had one of those switches with a actuating arm missing. Edited May 20, 2014 by km3h Share this post Link to post Share on other sites
