dual electric fan

dualsport wrote: What happened to Photobucket, did someone tip it over? Good thing you uploaded the latest drawing to the local server-

so are you saying where the fused 12v+ is coming into the top right relay i can hook up a fused IGN instead of it turning off after the car cools? also if it doesnt draw any power when the engine is cool then it might work better that way since when i turn off the car and the fans are on then it will continue to cool until the engine has dropped below the thresh hold of the temp switches

yea i have edited it a couple of times. here it is in the final

with ignition on a seperate relay

no ignition

is this where you are talking about introducing IGN to the diagram?

Well,  if you really want the fans to continue running even after you shut off the ignition, then you shouldn't use the ignition switch line-  in that case you'll want it all to be constant power, and rely on the thermo switches to shut everything off properly.

I'd go with the ignition switched setup myself, bit safer that way.  Fan switches have been known to stick on, though OEMs do use the non ignition switched setup, so they must be confident enough on their reliability. 

With the ign switched setup, if you really want to have the engine cool after a hot run, then just let the engine idle for a while before you shut down.

Also, you might want to use the switched ignition for the upper relays also, since the relays can't do anything without primary power coming from the bottom relay anyway.   Another bit of safety in case your fan switches fail and leave the relays energized while parked.  Not as bad as the fans running, but the relay coils can also drain down the battery after a while.

ok you make a good point. that is the original reason i wanted ignition switched because i didnt want to have to worry about an activated relay doing nothing while ther car was off. i will use ignition especially since the OEM temp switched wont work in my case (they are open at temp normally closed) plus i just dont want to use that many relays for a fan set up. if i wanted to cool the engine off after a hot run then i can have the car on engine off untill the radiator cools off enough then i can just restart and go. 

i am happy with this set up i am going to try it out soon. i just have to get the proper thermo switches. i found one on summit racing that turned on at 185 and turned off at 170. i will yse this one for the low speed. for the high speed i will try a 195 on not sure what the off is hopefully it is off at 185 lol