Relay thermal fan control

Hi guys, I have a situation where my ute has had a voltage leak which has in the past given me a flat battery. The ute does not have a pretty history as it has had a engine swap and a supercharger also added giving me 350+ ponies to play with but the wiring side is a mess. So bad that no one can hook up a to the BCM and diagnose any faults. So I have installed a Master Kill switch so I can guarantee that the battery will not run down but my battery still is not 100% recharged. I have now got an issue where I go to start the ute after its warmed up but because the radiator fans have been triggered by the Davis Craig thermal switch I don't have enough current to also turn the starter motor. Solution install 2 fan kill switches to I can control them on start up. I do not want to run numerous wires through the firewall and would prefer to only have the 2 (1 for each fan) My first thought was to use a relay to cut the negative from the fan. I have wired a relay for each fan with the below pin placement Pin 30 and 86 - Earth Pin 85 positive feed from switch Pin87 negative from Fan I have quickly tested this but did not have much luck... any Ideas?? Currently I have a manual Davis Craig thermal switch that feeds to 1 relay which connects to both thermal switches I would also like to have a LED to show when the fan is allowed to run and already have this wired in after the toggle switch(which is the only thing working atm) All help is much appreciated

https://onedrive.live.com/redir?resid=CBD889885D94AA2C!289&authkey=!AH4yU4odja6GGFU&v=3&ithint=photo%2cpng

The above link is how I think it could go.... still not sure if it will work

Best way would be to use an ignition interlock relay, I'll work out some diagrams and post later.

I just looked at the diagram, you have your 85 and 86 the wrong way round., BTW does the thermal fan really switch POS? Everyone I ever saw switches NEG.

Here you go, use a 70 or 80 amp relay, 87a is redundant in this application, you can use a 4 pin without 87a if it's easier to get:- fan_switch.png This will only enable the fan when ignition is on, also you can override the thermal switch if needed.