I've got an electric fan that came with a relay, but no wiring diagram.

There are numerous diagrams online and each of them look pretty similar. But they all vary a little as to which wire goes to which slot on the relay.

Does the red wire (30) go to the battery or to the fan? I have seen both on the diagrams. Does it matter?

Same with the wire that comes in from the ignition vs the wire that goes to the temp sensor. Each wiring diagram seems to be a little different. Some have the fan wire coming from the 87, and temp sender from 85, etc.


Can anyone tell me where each of the wires below should go?



Also, the black wire is a little confusing to me. Obviously it looks like its got a ground connection added to it. Does this wire go to the fan power? If so, do I need to connect that ground wire or will the ground wire from the fan be adequate?

Lastly, the fan came with a 30 amp fuse on the red wire, along with a 30 amp breaker. Do I need both? One or the other?



Here are some of the diagrams I have been looking at:

Either way is fine on that relay and application

I would wire the battery to 87 and the fan to 30 in case you ever have to replace the relay and only a 5 pin is available. That would keeps the bare uncovered 87a terminal from being hot at all times when the fan isnt used

Okay thanks.

What about the black wire and whether it needs to be grounded if its plugged into the fan, which has a ground?

Also, any insight on whether or not I need that 30 amp breaker AND the 30 amp fuse? Is it either/or?

the black wire in the first picture? I'll assume thats what were talking about

That would go to ground/0v/negative-battery-post. The white wire when given 12v turns on the relay. The black wire has to be tied to ground for the relay to function. I see 2 wires are crimped on the same terminal in that picture. I don't know where that second wire goes. If it goes to the fan, and the fan has another ground path through its mounting hardware then it would function without the ground terminal attached to the chassis.

Are you wanting to use a temp switch to turn on and off the fan? Depending on the temp switch you use, you may have to change some things around for that to work. 2 terminal switch would have power on one side, and the white wire on the other. 1 terminal switch would have the black wire cut off that eyelet terminal and routed to the 1 terminal on the switch, white wire would stay on 12v+

Yes i am using a temp switch with one terminal.

So should i wire as follows:

Red in pic- battery
White in pic - 12 v switched
Blue in pic - fan
Black in pic - temp sensor/switch

Or should I wire the black to fan power and blue to temp sender? This is what has had me confused.

And that black wire is also still confusing to me because it DOES have a second wire crimped to it. So the eyelet is for a ground, i assume. However, the fan is grounded as well. So do i need a ground I'm both places?

Gigemags05 said:

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Yes i am using a temp switch with one terminal.

So should i wire as follows:

Red in pic- battery
White in pic - 12 v switched
Blue in pic - fan
Black in pic - temp sensor/switch

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yes

Quote:

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And that black wire is also still confusing to me because it DOES have a second wire crimped to it. So the eyelet is for a ground, i assume. However, the fan is grounded as well. So do i need a ground I'm both places?

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yes you need a ground for both devices, relay and fan. The temp switch acts as the ground for the relay

Ok great. Thanks for walking me through that!

When I wired it up as described above, the fan runs non stop when hooked up to the battery. I assume something is wrong in the relay? Any ideas on how to trouble shoot it?

Think it could be a faulty relay?

Could be the relay; could be the temperature switch is stuck on. Unplug the relay and check the socket terminals with a test light.

The relay works like this: when a (small) current flows through the control side (85 & 86), it closes the switch between the load side (30 & 87), allowing a much larger current to flow. If you have +12V on one of the control side terminals and ground on the other, the relay will close. If the relay is closing without this condition, it's bad; otherwise it's your temperature switch closing the circuit when it shouldn't.