WongRS

iTrader: (11)

before i set this piece of crap on fire!!!!!!!!

Since it's been on the road, its done 1000 miles and it on its 4th alternator, can anyone figure this out?!

Basically, when we got it running, the alternator was showing (what i thought) was signs of age, needed to be rev'd to about 3k before it started charging, so i ordered a recon one from local parts people, turned up, put it on, fine, for a day or 2, then that needed to be rev'd to 4k before it started to work, so they replaced it under warranty.
That one lasts a week then stops working totally and leaves me stranded, again.
So, i bit the bullet and ordered a genuine one from ford, that came today, i fit that, and nothing, it doesn't work at all?!

The alternator is rewired, has an IGN + of 12v going to the D+ terminal and has a direct feed to the battery off the B+ terminal, both are tested and reading 12v, so no issues there.

It's not a heat issue, the manifold is wrapped up well, and the alternator has a heat shield round it, and it doesn't get too hot, i have put my hand up there after a blast, and although it's warm, it by no means untouchable.

So, am i missing something, or can nobody make a fucking alternator that works properly anymore?!

luke19790_3

Does it also need a wire to the dash, may be different to a turbo?

WongRS

iTrader: (11)

It's in the original loom, which is still there, but it doesn't work, none of the dash works really with the new ECU.
Surely that's just a warning for the driver, not a necessity for it to work?

Brendan

iTrader: (1)

can you measure the voltage ?
also try fitting it with a 50 amp fuse to see if it goes as it should not be drawing that sort of current unless lots switched on! if this is the case may be you have a short somewhere?

WongRS

iTrader: (11)

Voltage is 12v with engine off, 11.2 with it on. bosch 044, plus the ecu, all the gauges/lambda gauge ETC, all suck power and add up so without it being charged low 11's is what i'd expect.
there's no shorts on it, been through it loads of times, would pop a circuit breaker if it did (everything is circuit broken) bar the starter.

gibbo frst

iTrader: (2)

have you ran a wire straight from the alt up to the battery.. i had my alt tested and was all fine but the revs do drop a fair bit when everything switched on.. 90 amp one too.
mines the other way round voltage wise as i have around 11 with engine off then 13 odd when running..

botters

iTrader: (2)

does the battery light come on with ignition on and engine off then exstinguish when engine started? if it does not do both of the above then it wont charge

luke19790_3

Yes you need that wire or it doesn't work . On a turbo anyway

luke19790_3

Yes it needs it, I found this on my car when I had issues with my loom

scoooby slayer

iTrader: (4)

that alternator will need the bat light else it wont charge.

dojj

iTrader: (3)

you need the bulb in the dash to work for the alternator to work otherwise there is no charge going to the battery

so wire it up properly and the alternator will work and all them 3 that don't will work too

like magic

WongRS

iTrader: (11)

But the 3 have worked for a while then died, i really can't understand why it needs the dash light, the whole lot is bypassed. It's getting a 12v ignition feed from elsewhere to the exciter.
If it's got 12v feed at the exciter and 12v at the main, there is no other way for it to know the battery light isn't on, surely?!

dojj

iTrader: (3)

no, the alterantors are fine and dandy, but they don't provide electricty to the battery ebcause you haven't got the light on in the dash to fire the electricity the correct way

WongRS

iTrader: (11)

Any chance of explaining how, Dojj? (i'm not being arsey, trying to get my head round it)
There's a 4 awg lead from the + on the alternator directly to the + on the battery, how can it get lost going down there?

cabriolet

alternator warning light comes out of the alternator as earth it needs the resistance of the bulb in the system to energise the regulator once done it charges turning the light off by changing what comes out of the alternator to live the alternator will self excite if spun fast enough but will not charge at low rpm [put it back how it should be alternator manufacturers spend billions developing their systems]

RSGARETHW

iTrader: (3)

What he said ^^^^^^

cabriolet

well after 24 years rebuilding them i know a little bit

escoskmv

just try and wire the batt light up an see wot happens mate, got nothin to lose. ive got a escort xr3i alt on mine an its never let me down. xr3i starters fit the yb aswell.

WongRS

iTrader: (11)

How does the bulb get an earth from there, where?! there's 2 wires into the alt, a + and another +?
Again, i'm not arguing, i am soooooo fucking confused. It IS still wired up on the ford loom, so is as it should be, does the ECU have something to do with it?

scoooby slayer

iTrader: (4)

well put i knew it was earth and becomes live or something like that, all the old tractors and even my old chevy just has a single wire to battery and thats it it charges magically lol

scoooby slayer

iTrader: (4)

im pretty certain i remember going through this years ago when i was about 15 trying to fix old shit cars and checking wiring and an earth becomes live via magic somehow
i never did fully understand it.

WongRS

iTrader: (11)

is it something to do with the other take off on the alt, the tacho type one? Because there's no wire for that one?

WongRS

iTrader: (11)

Fair enough, i'll fit a couple of dynamo's off a pushbike i think, that would be more simple.

I find it massively strange that 1 of the alternator's worked perfectly for a while, then died, surely if the wiring was all wrong, that wouldn't of happened?

martysmartie

iTrader: (1)

The battery light is part of the charging circuit, it excites the field windings by sending a live feed to them, it WILL however work without it, you just need to rev, which by the sounds of it you have been doing?

It's a very simple circuit, when the alternator is stationary, a switched live feed is sent via the warning light and earths, as well as exciting the field windings, at terminal 'D', when the engine is running it has positive charge, so say 13V+, hence two lives on the bulb extinguish it indicating all is well.

Martin

1980blakey

iTrader: (1)

Is this any help?
http://www.alternatorparts.com/under...lternators.htm

WongRS

iTrader: (11)

Ahh, Marty, starting to make sense, the D terminal is currently an ignition switched 12v (from behind the radio, as it happens)
I have no idea why it's like this, TBH, as it was something i wasn't involved with. the standard wire seemed to lose its output when we fitted the new engine/ecu/loom.
So, fuck knows how i can fix that?!

martysmartie

iTrader: (1)

It makes no difference, although this does mean your HFS won't work!

Although it doesn't want to be a live feed you want a suitable bulb placed in the line (This could be what is what is damaging them)

On the OE setup the live comes from the instrument cluster, and then you will have a blue wire on the connector which is the same wire you see at the back of the unit.

The wire is well known for breaking, due to the heat from the turbo, so I suspect you have a break in this wire and the live is fine.

In which case just rewire this part, with a small ring connector to connect to the alternator.

FYI, the 'W' terminal is not used, this is for Tachos on Diesels mainly, and electronic chokes.

Martin

Brendan

iTrader: (1)

The voltage should not get lower when the engine starts as this means the bat is NOT charging! This means that more things are coming on as expected ie fuel pump and ECU to run engine but the output from the alternator is not running them or charging the bat!

Brendan

iTrader: (1)

does any one have the colour codes and where they go for the alternator wires ?

whizzisat114

iTrader: (2)

If you want to re-wire the field wire you'll need a ign live to one side of the charge warning light and the other side of the bulb wiring goes to your alternator,
this is earth whilst the alternator is not turning so putting the light on when you turn the ign on.
and it makes + voltage when the alternator is turning putting the warning light out as two lives dont make a circuit.
Make sure you have good clean earths as there just as important as the lives.

RobertM

If you wire the D+ terminal up from behind the radio without a bulb or diode in line you will damage the alternator. What happens is when you turn off the ignition key the alternator is still charging until the engine RPM is zero. This can take 1 or more seconds. In that time the little exiter diodes are powering everything they are connected to ie in this case at least your radio. They can deliver approx. 10 Amps, that's including the current needed for the field winding. They will eventually burn out.
So fit a diode in the wire to D+ and Bob's your uncle.

RSGARETHW

iTrader: (3)

What they all said ^^^^^

WongRS

iTrader: (11)

Hence the reason for the whole thread, my alternator doesn't work?! This is what i am talking about, the alternator is not working at all, i'm trying to figure out why.

WongRS

iTrader: (11)

Thank you mate, that's the clearest answer i've had and the most helpful, will give it a try.

Thanks for the input chaps.

carlo

iTrader: (4)

I got a headache years ago with the battery light thing as well the wire was broken going into the back of the clocks causing it not to charge