Mini indicator fuse blowing

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gt67
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Joined: Mon May 30, 2011 2:24 pm

Mini indicator fuse blowing

#1 Post by gt67 » Thu Jul 30, 2015 9:56 pm

My sister has a problem with her 1997 Mini Cooper. If she puts the the left indicator on, the fuse blows. However this only happens intermittently! It often happens soon after turning the car on. Once the fuse is replaced it will be fine for the journey.

It's got me baffled! Any ideas anyone?

History
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Re: Mini indicator fuse blowing

#2 Post by History » Thu Jul 30, 2015 11:51 pm

Take the fuse out and connect a 21watt light bulb to the fuse terminals on the fuse board.

Turn the indicators on. The bulb will lit up but dimly because its in series with the two indicator bulbs.

Then wiggle wires around etc. When the bulb connected to fuse board goes bright you have found the short. Look carefully at bulb holders.

Bob

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JPB
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Re: Mini indicator fuse blowing

#3 Post by JPB » Fri Jul 31, 2015 9:12 am

I'd also be looking at the lamp holders as a possible source of the short, but also have a close look at the stalk switch for the same reason, which is that the blocks which hold all of the tiny stud contacts are made of modern plastic instead of the much more stable phenolic resins - such as Bakelite for dark colours - which was used in the originals before the 1990s. These modern plastics tend to leak with the slightest hint of moisture in the air and in that set of circumstances, the substrate can and often does become less resistive than the studs themselves.

Check for any loose studs in the large plastic block that contains the contacts and the cancelling levers, a little nail polish (steal from a woman if you have to, but DO NOT use superglue for this ;) ) dribbled down the stud will hold it for some time but ultimately, the entire stalk may need to be changed. If that time comes try to find [a stalk] from an eighties mini as a replacement.

One last thing though; what happens when you switch on and use one of the other devices that's protected by the same fuse, such as the courtesy lamp? Does the fuse never fail when you open a door? Does your mini have its original panel of four glass fuses or has it been upgraded and if so, to what extent?
J
"Home is where you park it", so the saying goes. That may yet come true.. :oops:

gt67
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Re: Mini indicator fuse blowing

#4 Post by gt67 » Fri Jul 31, 2015 12:48 pm

Thanks John. It's a '97 mini so it's on blade fuses. Other devices on the same fuse are the clock, alarm and brake fluid test switch. Usually when the fuse blows nothing else is on- except the clock!

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JPB
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Re: Mini indicator fuse blowing

#5 Post by JPB » Fri Jul 31, 2015 5:00 pm

gt67 wrote:...alarm...
Image
:idea:

Have you tried disconnecting the alarm to eliminate it as a possible cause of this trouble? What breed of alarm system is it? Manufacturer's own, or an aftermarket device? I've encountered alarms in which diodes - present to prevent all four indicators going when the ordinary indicator switch was used - had failed short, so in effect bridging the indicator unit.
This would be more likely - but by no means certain - to cause a constant fault than a mysterious, intermittent one but it's worth checking anything that links the alarm to the indicators just in case. The fact that the fault usually occurs just after switching on would tend to support an alarm-related source of this trouble and it would also suggest that maybe it's temperature related, a bad joint perhaps? Making an unintentional contact when cold, breaking it when hot.
J
"Home is where you park it", so the saying goes. That may yet come true.. :oops:

gt67
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Re: Mini indicator fuse blowing

#6 Post by gt67 » Fri Jul 31, 2015 5:08 pm

It's all 100% as it left the factory so alarm is factory fit. Will have a go at checking the alarm idea. Will also check for any dodgy wiring- it has recently had most of the front bodywork replaced so possibly the restorer hasn't put everything back properly. Quite likely- he was a bit slack at the finer points.

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JPB
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Re: Mini indicator fuse blowing

#7 Post by JPB » Fri Jul 31, 2015 5:19 pm

In that case include every earth connection in your search for the cause of the problem. Some bodywork folk have been known to remove an earth and not replace it, or paint all over the clean metal that made that earth. You'll get there, it can be a frustrating task when the possibility of a random third party's human error is added to the list of things to look into, but you will crack this.
:thumbs:
J
"Home is where you park it", so the saying goes. That may yet come true.. :oops:

Topaz
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Location: Derby

Re: Mini indicator fuse blowing

#8 Post by Topaz » Wed Aug 12, 2015 7:00 pm

JPB wrote:Some bodywork folk have been known to remove an earth and not replace it
Bit late catching up with things after holiday so this is a bit of an old topic . .

What John describes is exactly what happened to my son's 1979 Mini - in his case it was the earthing strap from the engine to the bodywork. He had a few odd things happening and I got him to check various connections and then I said 'What about the strap from the engine' - 'What strap?' says he . . . . . :o

Mike

gt67
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Re: Mini indicator fuse blowing

#9 Post by gt67 » Thu Aug 13, 2015 6:28 pm

Wil have a look there then!

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