Ok, my parts are on order as I have confirmed my time delay module is faulty. Mine is a little different than the one Wm had (see post #17). The biggest difference is I do not have a D3 although there are holes in the circuit board where Wm shows it. Also my R1 is 6.8k, not 7.5k. Finally, my D1 is a TCI T6A40:
From what I have read, D3 is commonly called a snubber or flywheel diode used to protect the transistor from high transient voltages when the coil is de-energized. I believe the Ariens schematic is wrong here because it shows D3 in a direction that will not protect T1. Wm, your diagram and as-built original matches Ariens but you have not yet fried T1. I am not sure what to do. The correct placement of D3 should be across the relay coil so the output can flywheel back to the input when T1 switches off.
Hey Wm, I can not see how the ground gets connected from the circuit board to the metal can. It must somehow in order for the relay to ground through the red wire. Do you know how the circuit board and can are connected? Thanks.
Update: I checked by old Bosch relay and it indeed was diode protected which probably explains why my time delay module transistor (T1) did not fry. However, I have operated my PTO for 8-10 hours with a new relay which is not diode protected and the operation of the delay module did not change, ie it dropped out about 2 times per hour just like it did with the old relay. The installation of D3 as shown in the Service Manual and Wm's actual module will not do any harm but it will not do any good either, at least not in this application. Oh, I forgot to mention that my T1 is a MPS A06 which is capable of higher continuous base current.
Edited by artbuc, June 05, 2014 - 07:10 AM.