I am a dunce with electrical stuff, so please bear with me. Due to a faulty thermo switch for my electric cooling fan, I have bypassed the thermo switch by simply running the connecting wire to ground. This means the fan runs whenever the ignition is switched on. Fine for Summer, but not so good in Winter. I want to install a manual switch between the connecting wire and ground, but was wondering about using a relay. The fan circuit already has a relay, so my question is, do I need another relay for this ‘grounding’ switch, or does the fan circuit relay take care of it?