I wired in a sw at front bottom of cab in parrallel with the start switch on the PC. so it act the same as a normal start switch on the PC. Then I took a spare ATX power from the PC power supply - 12v and use it them to fire 2 x Fuse protected AUTO (Car Horn Relays) rated at 30A each. I did put a diode over the coils of the relays as well. The relays control the 12vdc and 5vdc to rest of the cab. So when I turn the PC on it in turn turns on the 12VDC and 5vDC. Cheap as to do.
https://www.ebay.com.au/itm/402956368363?chn=ps&norover=1&mkevt=1&mkrid=705-139619-5960-0&mkcid=2&itemid=402956368363&targetid=1280421173919&device=c&mktype=pla&googleloc=9071657&poi=&campaignid=12499394795&mkgroupid=123469081380&rlsatarget=pla-1280421173919&abcId=9300512&merchantid=7364522&gclid=Cj0KCQjwraqHBhDsARIsAKuGZeFElS_gWhftWXmIk_U-WvD2WjydYGMY9XeWWNY38H0CtSbv-ltL9KkaAmPbEALw_wcB What are thoughts of using a ready built industry vibration motor as a shaker motor for Vpin ? The cost is certainly attractive