one gose to the vac on the carb and the other two are directional so hook one to the vac and check witch one has vac then turn the switch and c if the vac gose from one to another then if its working when the switch is in normal mode the hose with vac gose to the rear line on the solinoid on the t/case I THINK but its been a while since i had a qaudratrac failing that you will just have to swap the hoses around i think the quad is working you are just bringing in the permadent side
also check the condition of the hoses because if there are any vac leaks it wont work
when it is working the emergency drive light should come on in the speedo hope this helps