Pto shuts off when I move forward

I have an older commercial walk behind Toro 30291 mower with hydrostatic and electric start. The pto shuts off as soon as I move forward. I'm not sure if it is the pto switch or the delay module. I can text the pto switch but don't know how to test the delay module.  I did test the two safety switches for the steering and they are fine. Any ideas would be appreciated.