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Tired idiot breaks car's electrics.- - FIXED!


Dyrill

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I really should have stopped working on the car much earlier and wouldn't have made this daft mistake but I was into it, the wife and kids were asleep, you know how it is. Working on dash electrics - dash off, scuttle off, wires and gauges everywhere - first new switch and relay wired in- mmm - I think i will connect the battery back up and see if it works... tired idiot connects negative terminal first then positive ( I know ) but even worse I forgot that the battery master switch is on as is the ignition switch ( fitted a new red cover to the existing toggle switch earlier). SPARK on battery positive terminal - click heard from right hand side of car and now there is nothing- no power getting to anything, zilch, Car has a immobiliser that is as far as I know not part of the system (wasn't given the fobs by previous owner etc) but I have obviously blown something up - Checked the fuse box -all okay. So what have I ruined that would cause this sympton. going to bed now rather fed up ☹️

 

Supersport 1.8 VVC

 

Edited by - Dyrill on 11 Jan 2009 09:03:52

 

Edited by - Dyrill on 14 Jan 2009 21:47:42

 

Edited by - Dyrill on 16 Jan 2009 12:59:24

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Thanks Ian. Fresh pair of eyes- all battery on, pre ignition functions working- phew! so hazards, lights, dash lights, flasher etc all work. pressed the interia switch, turning the key in the ignition barrel round and flicking the ignition toggle have no effect - no sounds of fuel pump etc heard. as you can tell - very new to electrics but determind to be competent by the end of my dash upgrade. Where should I be placing my multimeter along the circuits to see what's gone pop. Could it be the MFU ( was reading about those last night) that i have blown up? Or have i managed to somehow reset the immobilser so that it now works? Cold outside - not going anywhere for a while - would love to locate problem before Sunday lunch at pub 😬

 

Supersport 1.8 VVC

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Problem - the dash light has never been on the dash, I assume it was deemed surplus to requirments after the immobiliser's functionality was removed from the system - however after removing the scuttle and dash I have found a light connected on a red wire with a piggy back terminal to a brown wire comming from the immobilser, there is a black wire from the light as well which is not connected to anything. I assume this is the dash lights positive( red) and earth ( black ) wires- I put the black wire to the chassis - it does not light up. I have now taken out and checked all the connections and condition of the MFU which all looks perfect so I don't think it is that. I will search the archives for a detailed description of the immobiliser - it appears that no power is making it through this but I don't know which wires take the power to the immobilser to see if its is this that is stopping the power feed. If anyone reads this and as a description of the immobiliser wires I would be grateful for a link. Thanks.

 

Supersport 1.8 VVC

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Pull all the fuses one at a time and check em electrically Not visually [Deceptive we buggers] Before you do anything else *thumbup*

Note the ign Toggle If Aftermarket May have an inline fuse as well


jj

N.I. L7C AR 🙆🏻

Membership No.3927.

240BHP 1900cc K Series 40th Anniversary

 

 

Edited by - Johnty Lyons on 11 Jan 2009 12:55:52

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Hi Darren,

As suggested above..double check all fuses AND see if there is an inline fuse for the starter switch.

I can't see how you would have reset the immobiliser if it's not been in use, but if you can take the example of the fuel pump...check if it has power on the battery side of the fuse box (multi meter to connection in fuse box and earth anywhere)...from here follow the wire up to the immobiliser if you have activated it, the wire will be live going to the Immo, but dead after it...assuming you can see the right colour at some point after the immobiliser. I can't remember how mine was wired in.

 

Keep digging, the problem will turn up...

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Jeez! Here I am again at 1.00 am in the morning still none the wiser.

Fuses - all work fine.

Starter button - live on one side, press button live on other side.

Ignition cut on/off switch - no power either side- various wires.

Ignition barrel - no power either side- various wires.

Immobiliser - no power anywhere-open up - all looks good. Am getting confused about from what side and from which brown wires power is supplied and which takes it away as can't get a reading. Seems to me that I have a problem with the ignition circuit as lights hazards etc work.

Last thing for me tonight is to take some pictures of the switch, barrel and immobiliser etc and post them on here tomorrow. I MUST FIND THIS SELF INFLICTED PROBLEM!- Its got to be something simple ( like me *cry*)

 

 

Supersport 1.8 VVC

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  • Area Representative

Are you sure there are no inline fuses at all that are maybe hidden away in the wiring? Maybe a feed to the ECU?

 

As you say in your original post, you heard a click which suggests a fuse has blown and supported by a dead ignition circuit.

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OK - first thing - scrap your multimeter for a mo and use a cheap and cheerful lightbulb tester. Clip the crock clip to earth and then you can probe away now and watch the bulb. The multimeter is a great tool for some jobs but can be misleading, because when the display is set to volts that's exactly what you get. With a light bulb tester you can see if there is any actual CURRENT there, as well as the kind of voltage you have (by the brightness of the bulb) - it's a very powerful diagnostic tool.

 

Work your way from the battery (dont' forget to check the earths - they are very important) with your lightbulb tester and you will find the problem very easily I am sure.

 

(Also you want to check the big connector in the engine bay on the right hand side that connects the body loom to the engine loom. Sometimes the pins do not stay clipped in and create a fault very much like the one you are describing.)

 

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Oh well, defeat admitted- Can't find why the circuit does not work- once the brown, purple and white wires go under the tunnel I can't work out where they come out again to chase the feed. So have called an auto electrician in on Friday 😔 Day booked as holiday. Hope he can work out what I have done- Have asked to work with him to learn. 🙆🏻 🙆🏻 🙆🏻 ☹️

 

Supersport 1.8 VVC

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Jules,

I mentioned to Darren about checking the battery master switch...if he heard a click from the right hand side of the car, and he says, neither side of the ignition is live, is there something on the BMS which could be preventing things going live...

 

Gary

 

PS Edited to ask ...How's the family?

 

Edited by - captain chaos on 13 Jan 2009 23:08:47

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*wavey*

 

They're fine, thanks Gary - yes! Louis is three months now which seems to have gone very fast *eek* I've finally got my car booked in on a track day at Anglesey next weekend so I'll post up a running report with some first impressions!! (Hopefully good!)

 

...and back to this little problem.

 

Basically you know yourself (Gary) how to fix this - it's about the workflow from the battery through in a very methodical way. Thing is, Dyrill hasn't done it before and he's angry with himself for breaking it - plus he has no confidence in his own ability yet (which is easy to understand but as you know is quickly built as you work). The auto electrician will just come out and start probing things, (exactly like you can Dyrill) - he'll track from the battery, through this component, to that component etc... and will pretty easily find the problem. I can't think of anything specific in the BMS that could be the issue beyond test probing the input and the output that will confirm that the handle is working.

 

Dyrill - you didn't comment on that loom plug in the engine bay - have you checked that?

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Disappointed now more than angry I think Chaps,

 

The battery is fully charged - it was on an optimate until the day I took it off to take the scuttle and dash off. I started to work back from the battery to try to locate the problem as suggested- the BMS works fine and when you switch it on, the supply to the other side of it and to the starter motor is present . There is power at the starter motor- the wires then go back towards the bulkhead and get joined with a load of other wires all wrapped in black tape. I am not sure (because of my lack of experience and confidence) where the wires head off to next. The power to the lights, and dashboard switches is fpresent. The fuses all work, I am confused by the connections on the ignition switch, the ignition barrel and the immobiliser as there is no power at either side of these components and I am unsure on which side the power enters and exits. These IS power at the starter button however. So my conclusion is that there is a problem with the immobilser as this is in the area of the click I heard on that night. Having taken it apart to check the innards all 'looks' okay - I could be wrong - but there are no in-line fuses elsewhere that have blown as far as I can see and I do not have the confidence to strip all the tape off the loom at the bulkhead in case I cause more damage. If the wires were easily followed I am sure I could have worked out which one supply the different components, but I can't follow them without ripping apart the tape.

 

Just in case anyone is interested enough - I will describe what I can see - this a long post - please forgive!

 

Immobilser.

- Pin 26 -Brown thin wire on immobi goes to ign barrel pin - no current present at either end.

 

Ignition barrel

Thick brown wire goes from other side of barrel to one side of the ignition switch - no current present.

 

Ignition switch

Thick (but thinner) brown wire on other side of ignition switch goes to ECU 20 amp fuse - fuse works.- no power at fuse either side.

From other side of fuse, a purple wire goes into tunnel and joins the loom - don't know where it goes from there.

 

From the same side of ign switch one red wire is connected to 3 white wires - one goes into the tunnel, the other two white wires go to fuse box to fuse 3 and fuse 6.

 

One more white wire connected directly to the same pin goes to pin 1 on the immobiliser. From an email kindly sent by Mike Molloy this is the ignition wire. I don't know if this supplies the switch or the other way round.

 

So that's as far as I have got- Very busy start to the year at work - thankfully, so over to the professional on Friday 😬 some pictures of the components below.

 

here

 

 

Have a nice evening *thumbup*

Darren

 

 

 

 

Supersport 1.8 VVC

 

 

 

Edited by - Dyrill on 14 Jan 2009 22:10:36

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Darren your browns should be live at all times they are fed directly from battery

The ign sw is an after market mod designed to replace the key so supply must be to the barrel I honestly think the click is misleading I suggest you look at the source of browns [either BMS or battery ] It is most likely believe it or not that the problem is simply a disconnected Brown as there are usually two along with a red on battery and with a BMS these will just have changed location I think with the jumble of wires that you have just dropped a Brown somewhere The car has been modded to much from the std wiring to make the pictures you've posted any help Have another look youreslf before Fri I'm sure your NOT incompetent and you will surprise yourself, and be able to cancel the Auto Spk on Fri *thumbup*

Best of luck Johnty *wink*

 

Edited by - Johnty Lyons on 14 Jan 2009 22:41:25

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Darren

As Johnty writes, all the thick brown wires go to the battery +. The purple wire that disappears into the loom goes to the Multy Function Relay Unit here. I am not sure what model you have but the K EU2 and EU3 are the same in this case.

It could be that you have lost a ground connection somewhere. Where are you referencing your measurements to, chassis or back to the battery 🤔 The ground point for dash electrics tend to be at the wiper motor mounts, under the bonnet there are two large ground wires going to the engine block and some bunched together near the off side headlamp.

 

Good luck

 

Tom

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Just looked at the wiring diagramme and you should have a 12v feed from a fuse then to a wiring junction point and on to the ignition switch.

You might have fried a wire internaly and not getting a 12volt feed .

Try to bypass original wiring after the fuse and see what happens.

 

Good luck John

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Problem found! 😬

 

Birds nest of aftermarket wires was the main problem - it appears that when I reconnected the battery one of the live feeds that was supposed to attached to the ignition barrel managed to pop itself off ( perhaps that was the click I heard?- it was very loose and had too large a terminal , the sparky was not impressed with previous wiring *nono*-must have been hanging on by a thread. So new terminal fittted and now its nice and tight and all is well. Took him all of 5 minutes to spot it *redface* Yes - I felt like a d1ck head, but at least I now know what goes where. So back to the dash project now. New problem found - need to remove the roll cage to fit the new dash "with ears" as the old one was the one without and wont squeeze through the gap between it and the dash tubes after the bolts have been removed. time for another search....

 

Can I just say that the advice and encouragment was very much appreciated and I look forward to meeting many of you once the weather warms up and track days beckon...

 

Thanks again

Darren

 

Edited to say - Decided to remove ignition switch and go back to ign barrel and starter button on dash, and he is using loom wrap to make it nice and neat for the future- I can look forward to some sleep now.

 

Supersport 1.8 VVC

 

 

 

 

Edited by - Dyrill on 16 Jan 2009 13:05:53

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Great news Darren.

 

Don't feel "like a d1ck head" for any length of time. I'd guess that 80-90% of the guys on here wouldn't tackle a scuttle-off wiring job in a million years. The fact that you failed to spot someone else's f**k up is just one of those things. Plus you've learned a massive amount about fault finding and about the support and generosity of this club.

 

See ya on the road!

 

Steve

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