wiring up water pump and fan for water/air intercooler

[5inchgq]

I'm an absolute electrical noob and am trying to wire up an electric water pump and fan for a heat exhanger for my water to air intercooler. Ok what I've got is the pump and fan running in series? positive and negative wires run to a plug then split to both the fan and water pump? I've got the positive (red) wire (with 15amp inline fuse) to positive battery terminal and the to a switch in the car. To the switch I also have the negative (black) wire from the fan and pump and then to an earth. Now when I connect power (12v) with the switch on both the fan and pump work but when I turn the switch off the earth from the switch wants to get hot and melt?????? Can someone please tell me where I've gone wrong?

I drew a pic of how it's wired but the scanner has crapped it's self I thought it might have been easier to diagnose with a pic of how I've botched it if I get the scanner to work I'll post it up too.

Thanks in adance,

Dan.

[chimpboy]

Okay... first up the correct term for how you have them wired up is "parallel". "Series" is like a daisy chain.

It sounds like you've kind of messed it up a bit

Take the ground from both the pump and fan and just ground them to the body/chassis. They don't need to go to the switch.

Run your red wire from the battery to the switch, and then from the other terminal on the switch run it back out to the positives on both the pump and fan. That should be it. You shouldn't need ground at the switch unless it is an illuminated switch.

Leave your inline fuse in place, close to the battery and on the way to the switch is the correct location.

[5inchgq]

Thanks heaps chimpy I kinda figured it wasn't right when I got heat But I have NO knowledge about electrics (obviously )It once took me nearly a month to re-wire under the dash of an old HR I had even with a diagram