Jimmyw

Cooling fan fuse

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Where is the cooling fan fuse? The manual says that its in the relay box behind the battery of a mk 6 fiesta,all is there is just the two relays, no fuse.There doesn't appear to be power going to the feed side of both relays that control the fan with the aircon/cooling circuits.Relays are working.

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Fuse 12 in the passenger compartment (15 amps) according to Haynes but this also feeds the fuel injectors so if it had blown, you wouldn't be going very far. Try fuse FD in th eengine compartment fuse box (40 amp). I can't tell you any more than that from Haynes but there aren't that many fuses in there so check each until you find it. Hope this helps?

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Thanks Ed,

Talk about opening a can of worms? I had an issue with the cooling fan not coming on with the aircon, hense why I wanted to know where the fuse is.I initially cleaned up the big thick red cable on the batt terminal, then I wanted to try to clean the other side of it where it goes into the plastic thingy. Removed the relay box, batt clamp and finally discovered another fusebox???? Never knew there was one there Five fuses, 4 60a, and one 40a one..Opened the box and put my meter on the continuity setting to discover that the 40a one was blown.How is it possible to blow a 40a fuse so easily? I had earlier just removed the passenger relay to check which of the two aircon relays were for the high or low speed. I bypassed the 40a fuse (on a temporary basis) and turned on the aircon, and voila!! works a treat.Is this the only feed for the cooling fans?From the wiring diag the 15amp fuse you descibe is powering the activating part of the cooling fan relays?? On the look out for another 40 amp.

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The air-con should activate the fan in low speed mode which is the second relay from the edge. The thermal sensor and ecu also activate the low speed relay and if necessary, the high speed fan relay which is the one right next to the edge of the relay/fuse box. To check it is all working just let the engine idle up to temp and see if the fan works. Make sure your heater is switched off so the engine can heat up. As to the fuse blowing, did it just stop working or is this a new car to you and it wasn't working when you got it?

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Thanks, when you say thermal sensor, do you mean the item that is mounted below the rad and has a coil on it (resistor I call it).If so, this item has failed but when it was bypassed temporary, it still did not work the fan ,I thought the relay that controls the high speed of the fan was not wired through the thermal sensor?.The aircon did work all along,I just wanted to check which relay that activated with the aircon, so I pulled the relay under the glovebox, afterwards the fan failed to operate.The fan and aircon will work now, but with the blown 40amp fuse bypassed.Of course, this fuse will have to be changed, but this is the reason why the fan failed just how it blew in the first place.

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No, the thermal (coolant / temperature) sensor is screwed into the end of the cylinder head. What you refer to is just a resistor coil with a thermal fuse that lowers the fan speed.

There are a number of reasons why the fan might have blown, e.g. someone probing around and shorting something, the motor not starting to turn and drawing too much current, a chafed wire shorting to ground. You will have to replace it and see if the fuse blows again or lasts.

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Hi again, there seems to be some confusion here. My explanation might not be up to scratch....ha!. The fan itself is absolutely fine and is working. The resistor is the part that has failed. So, the fan and air-conditioning system is working okay now, but the resistor and the fuse is bypassed,but this is not going to be permanent. I was just wondering why the 40amp fuse blew in the beginning. You have explained possible reasons why it might have blown, thanks.

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