Make sure you connect any manually switched circuit in parallel to the existing fan thermo switch,as this will ensure the fan still switches on at the pre set coolant temp ( just in case you forget to manually switch it on ).
But I have to agree with Stevo123,s earlier post that if the cooling system is properly serviced there should be no need to manually switch in normal operating conditions.
Last edited by CAU; 15-09-2013 at 05:31 PM.