Start issue (fuse gone)

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gordone
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Joined: 01 May 2019, 13:51

Start issue (fuse gone)

Post by gordone »

Hi all,

I have a C4 2005 model with 1,4 petrol engine. I have not haven any problem with the car last years some days ago I washed the car on the outside in a machine (not in the engine room) and parked the car at my house.

some days later when I wanted to use the car, the start engine turned around (good speed) but the engine was not starting.....
No alarms in the display or anything....

Later the day I started to check fuses and found one 20amp fuse gone, instruction book indicate the fuse goes to car computer and cooling fan.

When I replaced the fuse the engine started up on first attempt... I stopped the engine and tried again and i t started on first attempt...
The engine was only idling (I was not test driving the car) I got one error de-pollution fail (never seen these error before).

Later the day when I wanted to use the car, it was back to basic... start engine running (
04.JPG
03.JPG
02.JPG
01.JPG
good speed), but the engine was not starting.
I was checking and the fuse was not gone these time...

I have tried to have the cooling fan on and off to see if there was any difference, maybe the fan has a earth fault?
But testing having the fan on or off has not given me any answer. When I turn the cooling fan inside the car on it will never start either with key switch of and on... maybe it was not running before either before the engine has started ? cannot remember...

What can the problem be? can it be that the car computer have a issue who shortcut the circle and took the fuse?
Why is it not happening again ? complete burn now ?

What can I do ?

Please see attached photos.
Last edited by GiveMeABreak on 01 May 2019, 14:13, edited 1 time in total.
Reason: The last 4 photos are duplicates of the same one posted - deleted

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GiveMeABreak
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Re: Start issue (fuse gone)

Post by GiveMeABreak »

Hi and welcome.

Can you post your VIN here, so I can check out the wiring for this fuse on the circuit diagrams.

gordone
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Joined: 01 May 2019, 13:51

Re: Start issue (fuse gone)

Post by gordone »

I found these plate after some searching....
Is these what you need?

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GiveMeABreak
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Re: Start issue (fuse gone)

Post by GiveMeABreak »

Yes, I just about got that (although it is in the bottom of the windscreen cut out, visible from the outside) for future reference. I've deleted the picture as you don't want your vehicle details displayed publicly. Leave it with me while I check on the issue.

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GiveMeABreak
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Re: Start issue (fuse gone)

Post by GiveMeABreak »

So fuse F1 (20A) is for the Engine ECU and the slow speed cooling fan relay. That's not same as the fan in the car, which is fuse F11 (40A) for the A/C and internal Fan.

gordone
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Re: Start issue (fuse gone)

Post by gordone »

Ahhh slow speed cooking fan!

What I don’t understand is why the fuse is not broken again, when the will not start.

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GiveMeABreak
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Re: Start issue (fuse gone)

Post by GiveMeABreak »

Just try synchronising the key again.

Lock the car and leave it for 10 minutes, then unlock it, put the key in the ignition (do not start the engine), turn the key to accessories position, press the lock button on the fob within 10 seconds, then release the key and remove it. Wait a few minutes then try starting it.

You may have an issue that has caused the fuse to blow, possibly due to water ingress from the pressure washer? I would carefully check the connectors and fuse box to make sure there is no water anywhere, but especially near the radiator fan. Make sure the wiring to the fan is not corroded or shorting.

Normally, when you switch the air conditioning on, the engine fan will come on slow speed at he same time. Switch the A/C off and the engine fan should stop.

gordone
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Joined: 01 May 2019, 13:51

Re: Start issue (fuse gone)

Post by gordone »

Thank you!

I will try these later today.

Will keep you all updated.

gordone
Posts: 7
Joined: 01 May 2019, 13:51

Re: Start issue (fuse gone)

Post by gordone »

I have now tried to sync. The key, but the engine is not starting....

What I don’t understand is why the car started after I replaced the broken fuse, if the key was the problem?

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GiveMeABreak
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Re: Start issue (fuse gone)

Post by GiveMeABreak »

It was just a suggestion given that the fuse is shared between the Engine ECU and the Radiator Fan - and seeing as it blew, it might have caused a glitch. I think I didn't quite understand your original post - it was a little confusing for me.

Best thing you can do now is try a reset. My recent guide is here:

viewtopic.php?f=51&t=61997

gordone
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Re: Start issue (fuse gone)

Post by gordone »

I will try the reset.

1. My car was dead.
2. Found a broken fuse.
3. Car started after I replaced the fuse, tried to start up the engine 2-3 times.
4. Later the day when I wanted to use the car it was dead again... but the fuse is not broken...

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myglaren
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Re: Start issue (fuse gone)

Post by myglaren »

Have you tested the fuse or tried replacing it with a known good one?
Sometimes the fuses look good but have gone open circuit.

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ksanturion10
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Re: Start issue (fuse gone)

Post by ksanturion10 »

I have some thoughts, that maybe helpful:
1. Generally, refusing to start should be connected to the ECU and not the cooling fan. But, because this fan was most closer to the water spray from the machine cleaning, I bet that the initial short was caused by it.
2. Because of the short, there are probably burns over the contactor pins into the fuse box, which prevent electrical contact with the legs of the new fuse. Recently I had similar problem, all my instruments went down suddenly and it turned out to be an oxidation layer over the legs of the F12 fuse (Xantia X1). -> Try to rub the contactor pins in the fuse box and those of the fuse (maybe it has already such oxidation layers) for better electrical contact (you could use also a contact spray cleaner, but be careful if you decide to spray into the fuse box).
3. I don't have the circuit diagram for this car, but I guess except the relay for the cooling fan (which could also be damaged by the shorting), there should be one also for the ECU -> try finding and checking it too.
4. Worst would be ofcource if the ECU had shorted.

Just a suggestions, I'm not electrical specialist.

BR

gordone
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Joined: 01 May 2019, 13:51

Re: Start issue (fuse gone)

Post by gordone »

1. I’m 99% sure no water was not coming in to the fuse box during the wash, the hudd was closed during washing.

2. I suspect the it is something with the ECU? But remember I was driving home, 15 minutes trip after I washed the car, and it was the next day the issue araise.

How can I test if the ECU is alive?
Can measure if the ECU has power?

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ksanturion10
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Re: Start issue (fuse gone)

Post by ksanturion10 »

I meant that maybe the cooling fan had shorted, because in 90% of all cars, it is situated behind the radiator, which in turn is behind the front grill, where there was spraying from the car washing machine.
I can not help you with the ECU stuff, but just from interest - with what amperage did you replaced the blown fuse, same as before or else?

P.S.: actually I can see the radiator fans drectly behind the front grill, before the radiator! No machine washing for my xantia :lol:
P.S.2: Actually it seems more complicated. I had burned relay into the box between the two fans. Don't know if it is discussed already, but for me, these 5-pin relays are shorting internally, when used as 4-pin only! Mine all 3 into this box where 5-pin relays.
Bought two new with 4-pins, only the change relay should stay with 5-pin configuration.
Generally this box is suspected even under a weaker sprays from hand washing in my view (bad design?) -> who cares, this cars are old already :-D