No,
Went through all my JD Tech manuals but nothing for a plain ordinary 145 or an LA 145
The 145 was 2006 only & the LA looks like it replaced in from 2006 to 2008
I have no technical details for your series and JD wiring tends to be a little complex.
From what you have said I would suggest the Reverse safety switch was not installed properly.
It should be on an arm under the frame near the transmission and is depressed when the control pedal goes into reverse.
On the latter series it can be installed with a lot of play so can be depressed when the pedal is in the neutral position as well as in the reverse position. and visa versa.
Being JD some of these are normally open & others are normally closed..
IF that has been put back wrong then the mower might think it is in reverse, so you might like to try activating the reverse mow control and see what happens.
Other than that, I will just be guessing.
It could be the PTO switch gone bad but generally they play up for a long while before going bad.