Jake Collie 3 #1 Posted December 11, 2013 I brought out my 1991 520H to get it ready for blowing snow after it sat in the shed all summer. It started well and runs well but the parking brake and air filter lights stay "lightly" illuminated while it is running. If I lock the brake on, the light lights up full power but when I remove the brake lock it goes back to being lightly illuminated. Does anyone have any theories about what is going on? Share this post Link to post Share on other sites
Save Old Iron 1,563 #2 Posted December 11, 2013 either corrosion on the display board caused by moisture / grass clipping accumulation or a defective display board. the indicator bulbs are controlled by transistor circuits which should either be fully on or fully off. in your case, there are electrical leakage paths causing the indicator transistors to turn on 'half way'. try removing and checking the board for any signs of corrosion or water intrusion under the coating applied to the surface of the circuit board. 2 Share this post Link to post Share on other sites
Jake Collie 3 #3 Posted December 11, 2013 Thanks much Save Old Iron. You helped me out once again. Share this post Link to post Share on other sites
Save Old Iron 1,563 #4 Posted December 11, 2013 BTW - you can continue to run the tractor without repairing the circuit board - these boards just 'indicate' the status of the safety switches _ they do not control anything. Share this post Link to post Share on other sites
Jake Collie 3 #5 Posted December 11, 2013 Thank You! Share this post Link to post Share on other sites