Electric fan rewire - melted a fuse
#1
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Year: 2000
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Electric fan rewire - melted a fuse
I am trying to rewire my electric fans that the PO put in.
They had the power lead fused with a 30A fuse. That went to a relay. The relay went out to the three fans, etc. There was no fuse from the relay to the fans.
What happened is the fans stopped working, I overheated fast, noticed that the 30A fuse holder from the 12V source was melted. No wires were melted though, just the fuse and the holder.
I bought a new kit and decided just to wire it up again myself. The only issue is that the new kit has the fuse going from the relay to the fans. There is NO fuse from the 12V source to the relay. What is the correct way to do this? Fused 12V supply or fused to the fan?
Any clue on what could cause the fuse to melt? It worries me. Maybe just bad luck. This time I am going to use the battery as my 12V source. Currently it is on the power connection at the fuse box.
Thanks!
They had the power lead fused with a 30A fuse. That went to a relay. The relay went out to the three fans, etc. There was no fuse from the relay to the fans.
What happened is the fans stopped working, I overheated fast, noticed that the 30A fuse holder from the 12V source was melted. No wires were melted though, just the fuse and the holder.
I bought a new kit and decided just to wire it up again myself. The only issue is that the new kit has the fuse going from the relay to the fans. There is NO fuse from the 12V source to the relay. What is the correct way to do this? Fused 12V supply or fused to the fan?
Any clue on what could cause the fuse to melt? It worries me. Maybe just bad luck. This time I am going to use the battery as my 12V source. Currently it is on the power connection at the fuse box.
Thanks!
#2
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Whenever I wire anything with a relay I put the fuse in the wire going from the battery to the relay. You want the fuse as close to the battery as possible.
How many amps was that fuse holder rated for? Maybe it got too hot and melted but you were still drawing under 30 amps.
I would have 2 fans on one relay and the third fan on its own relay. This way if one fuse blows or one relay fails you still have at least one fan running and might be able to limp home without overheating.
You do not want to be pulling that many amps through the fuse block. Combined with all the factory stuff powered through there adding 3 cooling fans could blow the big fuse that protects the whole fuse block. Wire it direct to the battery and be sure to use a thick enough wire. For 3 fans I would use at least 12ga maybe 10ga wire.
How many amps was that fuse holder rated for? Maybe it got too hot and melted but you were still drawing under 30 amps.
I would have 2 fans on one relay and the third fan on its own relay. This way if one fuse blows or one relay fails you still have at least one fan running and might be able to limp home without overheating.
This time I am going to use the battery as my 12V source. Currently it is on the power connection at the fuse box.
Last edited by G_P; 08-07-2010 at 06:50 PM.
#3
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Okay, what I ended up doing the two relays. It seems like a much safer route to me. I have them wired up to the battery this time as well. Everything is working great for now and it is a much better install then the PO who hacked up almost every wire for some reason.
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