Hi,after changing the battery on my son's 1999 1.2 the car turns over but won't fire up.I removed and refitted the battery terminals in the right order,i can hear the fuel pump buzz when i connect it but i have no central locking, electric windows,flashers,and the fuel gauge.i have remove the terminals and cleaned them and they are in good condition as well as the gearbox terminal.

Thanks Shaun

shaun said:

Hi,after changing the battery on my son's 1999 1.2 the car turns over but won't fire up.I removed and refitted the battery terminals in the right order,i can hear the fuel pump buzz when i connect it but i have no central locking, electric windows,flashers,and the fuel gauge.i have remove the terminals and cleaned them and they are in good condition as well as the gearbox terminal.

Thanks Shaun

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A fuse has probably popped
Carefully check every single fuse (remove and inspect)
Do it 1 at a time ans rememeber where it came from

Ziggy

Sent from my SM-G920F using FIAT Forum mobile app

Thanks Ziggy

The fuses are ok and they are separate to each item

I'm thinking like Ziggy. Might have to go back further up the supply to find a common fuse for that lot which could be the F2 Maxi fuse in the engine compartment fusebox, 40A.

Thanks Brendan W

I,ll try that

Just thought i would try and start the car this afternoon and it fired up first time.I moved it and left in running for 5 minutes went back about 1/2 later and will not start again,same issues

Hi again, i have been out today and all the fuses are ok.I have check and put extra earth cables from the battery to the gearbox with no luck.Any other suggestions

Shaun

shaun said:

Hi again, i have been out today and all the fuses are ok.I have check and put extra earth cables from the battery to the gearbox with no luck.Any other suggestions

Shaun

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Amongst other problems it looks like you have an electrical connection problem with the body computer behind the fuses in the passenger compartment. Most likely culprit must be disturbance of the Earth wires in the engine compartment


On my 2004 car on the **same** cable going between the battery earth and the gearbox earth there is a connection to the chassis and on that same bolt there is a connector for a large number of Earths that go all over the car.

Have you been through every electrical device and noticed which are not working? The bigger the list the better as it will help narrow down the fault.

Check you have a good earth on the wire that connects to a bolt on the engine ECU - thats the thing with the large plugs with zillions of cables coming from the plugs.

Thanks judderbar,I have checked all the earths i can find but not the one from the ecu.I have put new earths from battery to body then onto the gearbox.I will do the ecu and fuse box one tomorrow.I am going to buy a scanner and see if that comes up with anything

It is also worth removing the bolt from the Earth lead connection to the body and giving it a good clean. I Had an issue where mine wouldn't start and thought the problem was the Starter motor packing up. I didn't replace the Earth to the gearbox (Mainly as it wouldn't undo from the gearbox) so added a second lead from battery to gearbox and also to the Body connection (£3 from Halfords for new leads). Whilst I was fitting these I gave all the connections a clean and since then car has had no starting issues

Thanks Scudmonkey, i have try all that, i have taken out the BCM and there is moisture on the top right hand corner of the board.What is the best thing to get it off.I think the board is shot but it is worth a go

Hi again,i have the BCM out, i know i need another one with the same number, do all the other numbers on the cover need to be the same as well

pic

shaun said:

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The Body computer is not a straight swap even with an identical unit. You need to unsolder the existing units eeprom and put it in the replacement unit.

shaun said:

Just thought i would try and start the car this afternoon and it fired up first time.I moved it and left in running for 5 minutes went back about 1/2 later and will not start again,same issues

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You should fault find the ignition system. The coils are right next to the battery department and could have been disturbed. The coils have a continual 12V feed and then get an ignition earth from the ECU. Using a car headlight (you need to show you can get a good current) test the 12 volt continuous feed at the coil and test the headlight flashes when connected to the ECU ground wire that goes to each coil when you crank the engine.

Most likely you have one fault related to the battery change rather than something exotic

Thanks judderbar,

I will try that thanks again

shaun said:

Thanks judderbar,

I will try that thanks again

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Thinking about it now my advise was not very good. Evidently you do have a problem that is more than the coils not working.

I was wondering why the electric windows, central locking etc was anything to do with the ECU

Is there anything else i can look for, i am struggling at the moment

Thanks

On my 2004 mk2b the large black relay in the passenger fuse box is the electric window relay T13. If I put a wire in the larger (top and bottom) contacts in the fuse box for that relay the electric windows operate without the ignition being turned on. If you can get the windows to operate it will show the problem is being created by the body computer not energising that relay.


Since you were able to get the car to start one time it is worth reliably and robustly connecting a small test light to the smaller (left and right) T13 relay contacts. Make sure you insulate the light end of the wiring. With the ignition on, if your fault exists the light will not operate but if you move the wiring around in the engine compartment you might find you can get that light to work and then trace the problem with the wiring.


If all else fails hammer here and there and see if the light flashes.

If that fails then if you get an identical body computer and the electrical problems are cured you are likely to only need the eeprom swapped over by a tech to get the car to start.