charging light

[bigblockmark]

Hi folks,can anyone help.Took my chim out yesterday and noticed the battery light came on at idle but has soon as revs reached 1400rpm it would go out.As it went out when revving i decided to carry on and go for a blast.Did about 30 miles of fairly hard drivig without missing a beat.Stopped for some of shells finest but when re-starting the battery bairly had power to turn engine.thought it might be the 100amp fuse,but why would light go out,or could it be the alternator.Any ideas.
Cheers
Mark

[jonathant]

Identical symptoms to mine when my 100A fuse had broken - alternator light on when idling, goes out and stays out when revved. I can only assume that since the fuse was cracked and not blown that there was just about enough current flowing across the crack to extinguish the alternator light.

Bizarrely, a broken 100A fuse seems to knacker my oil pressure sender too (underreads).

[bigblockmark]

Thanks Jonathant.
Know what i will be doing tonight then.Why is it in such a crap place.
Mark.

[keithyboy]

Sounds like the alternator - faulty diode pack? I had similar problems in my V8S a year or so back - twice actually.

[dickymint]

keithyboy said:

Sounds like the alternator - faulty diode pack? I had similar problems in my V8S a year or so back - twice actually.

I think the usual sypmton for this (on a Wedge anway) is the charge light stays on even when key is out.

[bigblockmark]

I had the diode pack changed a while ago,but that was causing light to stay on when ignition was off,as the man said.If the fuse seems ok,then i guess the next step will be to get alternator checked out.
Mark

[jonathant]

bigblockmark said:

Why is it in such a crap place.

FWIW, since I've had this fuse let me down twice** now in six years of ownership I've asked my local to change it as part of the regular servicing. Scary thing was that the fuse that came out after only twelve months of use was nearly shot through.....

** the first time was total loss of power on a French autoroute in the overtaking lane didn't know what was wrong at the time and the Chim had to be shipped home.

[FlipFlopGriff]

Always worth carrying a few of these in the car as spares - only a few pence each, no weight or space loss, an invaluable of needed.
FFG

[bigblockmark]

2 grams for the spare fuses,but 30kg for the trolly jack to fit it.
Thanks for your help everyone.

Mark

[dickymint]

Why not change it for a circuit breaker - if it trips just reset it. I've done this for my coolant fan fuse which used to blow often. (common on a Wedge).

[bigblockmark]

What a good idea,has anyone out there done any sort of conversion like this on the 100amp fuse.

[bigblockmark]

After lots of crwawling around under my car last night,found that 100amp fuse was all shiney and in one piece.Took alternator this morning to be tested.
They found that it has a faulty regulator,all fixed £40 .result.
Thanks for your imput.
Mark

[mrsflipflopgriff]

bigblockmark said:

After lots of crwawling around under my car last night,found that 100amp fuse was all shiney and in one piece.Took alternator this morning to be tested. They found that it has a faulty regulator,all fixed £40 .result. Thanks for your imput. Mark

Did you check the connections are OK to and give them a good smear of copperslip or similar?
FFG

[dickymint]

bigblockmark said:

What a good idea,has anyone out there done any sort of conversion like this on the 100amp fuse.

Something like this..............

http://rswww.com/cgi-bin/bv/rswww/lineActio

But get a spark to confirm the spec you need (my disclaimer)!

edited to say DOH! RS doesn't like to be linked to - you'll have to do a search

>> Edited by dickymint on Wednesday 5th April 08:53