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Alt. earthing
scutter - 21/6/08 at 11:43 AM

A very quick question, Does the Alternator earth through the body of the unit for charge light circuit?

I've a very nice alt bracket which is powdercoated and isolating the alt from the engine and it's earth strap.

Will a small earthing strap from alt to engine fix this problem.

ATB Dan.

mookaloid - 21/6/08 at 11:58 AM

A bit of wire temporarily fixed to the Alt and the egine block should tell you the answer - it can't do any harm

tks - 21/6/08 at 11:59 AM

uhhhh....

it will deff need a very good earth..

so i suggest... that you brake locally the surfice...

if it can charge 60amps it needs an earth of 60amps... so depending on the rating of it it will need the earth...

the light doesn't neaad earth because it takes the earth int he dash..and the power from the alternator..

Imagine your charger it has 2 leads to charge your battery... so needs your alternator..

Tks

BenB - 21/6/08 at 12:08 PM

Or hows about getting a nice big earth strap with "eye" ends. Drill out the eye end to the same size as the alternator adjustor bolt and put the strap eye under the bolt on the adjuster arm.... Earth the other end to something nice and chunky on the chassis....

scutter - 21/6/08 at 03:06 PM

Ok. I agree with everything said except the fact the Alt charge light earths at the dash it earths through the alt and when the alt is charging it removes this earth so switching off the light.

Time for a big bonding lead.

ATB Dan.

tks - 21/6/08 at 06:39 PM

quote:
Originally posted by scutter
Ok. I agree with everything said except the fact the Alt charge light earths at the dash it earths through the alt and when the alt is charging it removes this earth so switching off the light.

Time for a big bonding lead.

ATB Dan.


mhhhh you could be right about that one...
but also wrong...

anyway... it needs earth and a good one 2

02GF74 - 23/6/08 at 10:46 AM

quote:
Originally posted by scutter
Ok. I agree with everything said except the fact the Alt charge light earths at the dash it earths through the alt and when the alt is charging it removes this earth so switching off the light.



correct.

charge lamp is connected to 12 V at one end, other is at alternator. when alternator is not runing, it earths the lamp so it sees 12 V and thus is illuminated.

when alt is running, the voltage rise to 12 V - volt drop across lamp is 0 so it goes off.

.... yes, alternator earth is via the body so thcik earhc strap or fat wire is required and try to connect to -ve of battery as directly as possible. engine/gearbox and chassis should have earth straps too.

martyn_16v - 23/6/08 at 12:37 PM

quote:
Originally posted by tks
mhhhh you could be right about that one...
but also wrong...


very zen

scutter - 23/6/08 at 06:03 PM

All sorted, yes i had to add an earth strap, see attached pic, it goes between iether end of the Alt. tnesioner. Also helped with charging if the 12V supply to exite the Alt. was live, a fuse had blown.

All working well now, accord to the MS it's kicking out 13.7V

Cheers to everyone for there help, ATB Dan.


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