New Holland Tractor 1530 1630 1725 1925 TC25 TC25D TC29 TC29D TC33 TC33D Electrical System Repair Workshop Service Manual 29. YouFixThis_Traktor_Screen_1_C.jpg' alt='New Holland Tc33d Manual' title='New Holland Tc33d Manual' />Tractor wont start. PTO safety switch Well theres always a way to bypass the switch. Question 1 Can you get a meter and check the switch. With the tractor off and the wires at the switch removed, probe the switch contacts. Disengage the PTO lever switch resistance should be infinite no continuity, engage the PTO lever switch resistance should be 0. If the switch proves okay, have a look at your wiring diagram to see if there is a relay for the PTO safety circuit. This may be the problem. You can do the same deal on checking the contacts, but this time the key will need to be on the electrically pull in the relay. Cycle the lever and see if the contacts open and close. Pulling the fuse that you think is the right one may not do it since the use of relays allows for split circuits. Just be locgical. A wiring diogramn is essential. It should be in your manual. New Business License Listings Atlanta Ga Zip Code here.