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MG MGF Technical - Fuse problems

1996 VVC.
Main fuse box fuse 12 has just blown for the 3rd time in 6 weeks, twice while in France over last 2 weeks. Currently fuse less (sorry, no pun intended).

Have lost, and handbook confirms, Clock, Radio, Interior Lights although Clock appears to continue working when ignition is on (it is now acting as an "elapsed time indicator" rather than a "current time indicator").

Also appear to have lost SuperLock but have normal remote locking.

Can live without Clock and/or Radio, Interior lights could be usefull but hate having no SuperLock.

Workshop manual does not have a wiring diagram; is one available?

Can anybody offer any clues before I start speaking to an MGR dealer?
JohnP

This fuse supplies a large number of 12v feeds - mostly with purple wires.
Dieter's site used to have links to wiring diagrams.

Does the fuse go when you do anything in particular ?
eg opening bonnet or boot ?
I can't see how the clock would work with ignition on - it must have some sort of supply through some other device.
I would put a fuse back in and then open doors, boot, bonnet etc until the fuse blows. Hopefully it wont be anything worse than a duff bulb.

Steve
Steve

Hi John,

I think you will find this is a "common" fault and is usually caused by a short in the cable loom by the boot hinge.

However that said, a friend of mine also had the same symptoms....

Checked all the wiring out in the boot and it seemed fine. I did find a couple of rubbing wires behind the radio and repaired these. (The best way to check this is to remove the air vent above and you can see the area easily then).

It was okay for a while but has started blowing the fuse again, so maybe not the end cause.

Paul


P.S. his started when he was in France also.... Maybe a co-incidence? Or is it a Citroen plot.
Paul

Fuse 12 supplies boot lamp, bonnet lamp, footwell lamps, lamps in mirrors, radio cassette, clock and lamp in glow ring around ignition switch. Also supplies the alarm LEDs.

I would suggest that it indicates a problem with either the bonnet or boot or door wiring since it won't superlock. If you leave a door, boot or bonnet open it will prevent superlocking. Boot hinge is the common place for probs!

Good luck

Bruce
Bruce Caldwell

Thanks Bruce - I had too limited a view of 'interior lights' and completely ignored the boot/bonnet lights etc.

Feeling a bit dim now - which/where are the alarm LEDs?

I feel a weekend with the wiring is coming up.
JohnP

John

The alarm ECU is behind the Facia - you can see it from the left hand footwell after removing the cheek cover (with the foot well light) and you will also see the aerial for it.

The volumetric sensor is behind the the top central bulge in the T bar.

The only alarm light that I have seen is in the central lower part of the instrument biannacle.

If there are any LEDs they are hidden.

Good luck
Ted - a weekend with wiring sounds sexy (NOT)
Ted Newman

John

As Paul mentioned above I have had exactly the same problem myself but despite spending some time trying to track it down I have had no success. The last time (about 3 weeks ago) I replaced the fuse immediately, it didn't blow and I have had no problems since ... it is therefore an intermitant fault and as a consequence is proving almost impossible to trace.

If you find anything please post it and we can compare notes. Interestingly I have had no experience of the fuse blowing whilst the car is being driven but it appears to happen at some point at the beginning or end of a journey (perhaps when the boot, bonnet or doors are used). The boot wiring has been thoroughly checked and appears to be perfect.

Simon

Simon

John,

As TEd mentioned the alarm LED is the one in the instrument binnacle behind the steering wheel. I should have said 'alarm LED' as there is only one. It flashes when the alarm is set, rapidly for the first half minute or so and then slow flashes from then on.

Bruce
Bruce Caldwell

The sun is out, the sky is blue ... and I was about to go and have a look at the car but thought "roof down and go for a drive instead" as I'm still on holiday untill Monday. Will try to check it out in a couple of hours.

Simon: I think you are right - I don't recall the fuse blowing while on the move but notice it once I'm driving.

Bruce: I asked where the alarm lED was and then jumped into a very hot bath to read Pamela Stevensons biography of Billy Connolly. His story made me realise what a stupid question I had asked - the alarm LED is right in front of me when I drive the car. Never really noticed it much because it should be off except when armed.
JohnP

Bruce /Simon

I've found the problem break in the purple wire to the boot light.

The break on mine is at the Y junction where the boot lid wires leave the main loom near the hinge. I peeled the spiral cover back at that point and found visible core showing through a crack in the purple outer. I wiggled it about a bit (sorry if I'm being TOO technical at this point) and the interior lights went out. Sure enough, the fuse had now blown.

Visible ends are only about 2 mm long, not sure if I can join them but at least I can show the problem to an auto-electrician who should be able to sort it out.
JohnP

I shall be at Stanford hall tomorrow BRG N529YBD
JohnP

Me too,

Flame red VVC P503PRJ, with an old git at the wheel.

Bruce
Bruce Caldwell

bump
JohnP

JUST HAD THE FUSE PROBLEM, CLOCK RADIO, INTERIOR LIGHTS. TRACED PROBLEM TO BREAK IN CABLE LOOM AT REAR BOOTLID HINGE.
steve

That Bruce knows what he's talking (typing?) about.
JohnP

Thank you JohnP. Were you at Stanford? I forgot to take a note of your number so I couldn't tell if you were there or not. I called in for about half an hour or so and was amazed to see so many cars but so few people. Where were they all? Looking round the hall or in the tea shop? I was brought up in the next village so didn't have far to travel!

Bruce
Bruce Caldwell

Hi Bruce

Yes we were there but like you I forgot to note regnos.

We stayed about 2.5 hours, lunched in the tea room, used the necessary facilities, spent money with Mike Saturn, spent money with the F Register, chatted with Stu, went home.

Don't know where everybody went - I think most just strolled around the grounds although some seemed locked into their cars hiding under hats.
JohnP

>spent money with Mike Saturn<

LOL - I hope that was a typo John, Mike maybe after your cash but as far as I know he hasn't actually got horns growing from his head!

Ted
Ted Newman

Sorry for the late contribution...
the wireing digs are here
http://www.mgfcar.de/schedules/
thanks to Dieter
a good way of testing for this kind of fault is with a 12 volt lamp, wire the lamp into where the fuse fits and go around wiggleing wires untill the lamp goes on or off, or flickers (depending on the state of the joint), when it does this you have found the area that the wire is faulty.

Will
Will Munns

Thanks Will, I shall have a good look on Dieters.

Ted, Lyn says he is the devil incarnate!
JohnP

Ted,

I think you are confusing the devil, Satan, with Saturn, the planet. But I suppose he does run rings around......

Bruce :¬)
Bruce Caldwell

<<a good way of testing for this kind of fault is with a 12 volt lamp, wire the lamp into where the fuse fits and go around wiggleing wires untill the lamp goes on or off>>

Couldn't agree with you more Will. I have an old fuse with wires connected from it to a 5W 12volt bulb for that very purpose.

Bruce
Bruce Caldwell

Couldn't think of anything to say about the planet so I stretched my imagination a little - didn't think about rings:-)

Ted
Ted Newman

<<Don't know where everybody went - I think most just strolled around the grounds although some seemed locked into their cars hiding under hats>>

That was my wife! Hates MG meetings and wouldn't even get out of the car.
Bruce Caldwell

And she looked delightfull.
JohnP

Thanks everybody.

Took F into Diamond (Hatfield) on Friday and they stripped out the broken section from boot into loom and replaced with all new wiring. Their replacement section is longer and shaped into an "S" so that there is a double spring action when the boot lid is opened.

They also valetted the car and made the wheels (suffering from nearly 3000 miles of brake abuse) look great.

Nice man helped 'madam' into the car and checked that her seat belt was fastened nicely.

All done f.o.c. (probably under the AA warranty that they paid for when I bought the 1996 car from them at Easter this year).

Usual: no connection other than satisfied customer. Can only speak as found.

JohnP

This thread was discussed between 20/09/2002 and 29/09/2002

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