My 500 rear heated window and heated wing mirrors are not working. I checked and found that fuse # F20 had blown. I replaced it with another 30A fuse but it keeps blowing. I'm looking for some likely causes as I think this one will be hard to trace

Tim P said:

My 500 rear heated window and heated door mirrors are not working. I checked and found that fuse # F20 had blown. I replaced it with another 30A fuse but it keeps blowing. I'm looking for some likely causes as I think this one will be hard to trace

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I'd check the wiring into the tailgate door first. Check that it hasn't chafed.

Tim P said:

it keeps blowing. I think this one will be hard to trace

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Easy to trace! fault is always there, trying doing one that occurs every month or so:bang:

Thanks T14086 and Most Easterly Pandas

Indeed it was in the "flexible" or not so flexible wiring loom that goes to the tailgate. It was blowing 30a fuses when it shut the tailgate.

I cant beleive the poor state of this wiring (it looks like a really poor design to me) Im an eletronics engineer and ive seen this type of fault before. It looks like the insulation is not the correct material and cracks when its flexed in cold weather.

What do you think?

Crikey that is bad!

Tim P said:

ive seen this type of fault before

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me too (old rovers anyone), some manufacturers never learn

Tks T14086 and Most Easterly Pandas, I glad you think its bad too ! This is a 4 year old car and definatley a design fault in my opinion. There are a number of cables in this loom (some heavy fused at 30A and some considerably smaller). Nearly all cables are bare and should a large cable touch a small cable i believe there could be potential for a fire risk. I shall take this up with FIAT and let you know what they say.

Not a fire risk as as proven, adequately fused however the design is awful!

Hi T14086 I think fire risk depends on which wire touches which - Its ok if the two large ones touch as each cable is rated for the current - However if a small cable touches a larger one then the small one can heat up before taking out the 30a fuse - Also some of the strands on the cable are breaking so eventually when down to a few strands the conductors will get hot before taking out the fuse. All in all its an appauling design and needs to be corrected by Fiat

Tim P said:

Thanks T14086 and Most Easterly Pandas

Indeed it was in the "flexible" or not so flexible wiring loom that goes to the tailgate. It was blowing 30a fuses when it shut the tailgate.

I cant beleive the poor state of this wiring (it looks like a really poor design to me) Im an eletronics engineer and ive seen this type of fault before. It looks like the insulation is not the correct material and cracks when its flexed in cold weather.

What do you think?

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Good to see I'm not the only one with mossy bits in my tailgate!

Common fault on 500's and yet another thing that spoils the 500 experience.

Tim P said:

Hi T14086 I think fire risk depends on which wire touches which - Its ok if the two large ones touch as each cable is rated for the current - However if a small cable touches a larger one then the small one can heat up before taking out the 30a fuse - Also some of the strands on the cable are breaking so eventually when down to a few strands the conductors will get hot before taking out the fuse. All in all its an appauling design and needs to be corrected by Fiat

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you could say this about any larger cable running alongside a smaller one in the car or any other device.

Going to check this out and see how bad it is as well.

I thought it might just be one or two which were exposed, not the whole loom.

It should be a recall to be honest for that.

The tailgate wiring failed on mine. A quick trip to auto electrician sorted it out. £110

My high level stop lights failed found to be cut wires in loom.Replaced with new cables they now work but no. plate lights and boot handle have stopped working I presume the loom is at fault again.:bang:

This is my first post so apologies if this is in the wrong section. I too have the broken wires between the body and tailgate grommets. Intermittent tailgate lock action, non working number plate lamp and HRW. I could make the tailgate lock work by squeezing the rubber between the grommets. It is evident that the rubber has been trapped against the bodywork as the paint has been rubbed away. I would also say the difference in stiffness between the grommet and the concertina tubing has fatigued the wires. Only two were intact. All on a car that isn't yet 4 years old? Dealer was very non committal, inferred he had seen it once. Parts man said a new loom is needed at £700. I have put a temporary fix in for the MOT but I would be interested in what response you had from Fiat.

Take it to an auto electrician Have the job done at a Fiat dealership and it'll just fail in the exact same manner, there's no point. Have an auto electrician sort it and it'll be good for the life of the car.

Hey,
I have a question.
Today I checked my trunk wire loom and almost all the cables were broken and corroded. I reconnected everything back, but now the window heater(trunk) doesn't work. odd thing is that mirrors are heating. So is there seperate fuse for rear window heater ? if so were can I find it?