radiator switch manual

[f117v6]

I have a manual switch that was installed in car before i owned it,,,,,,,Here is what is the problem is worked great for years if i shut car off and it was hot i could put ignition switch to run and turn man. switch on could turn ignition switch off leaving man. switch on and would run for the ten minuites or so.Now the fan wont stay on when i turn ignition switch off.....I just tried a brand new delay relay didnt work......Fan still works ok i just want to be able to have the cool down time again.,,,,,i am posting for help because im tired my power master went out on monday and just got it fixed thanks guys..