Battery light on

[Glyn Harper]

When it stops charging, the voltage does drop sharply when measured at the battery.

It's possibly it's a broken wire that is making an intermittent connection. Probably not the main battery wire, but the smaller one. I know these can go brittle. I'm going to investigate that wire tomorrow, and possibly replace it as far back as I can in case it's gone brittle in the engine bay.

The battery is quite new (well, a couple of years old) but it's always been on a trickle charger so should be in good shape.

I'm wondering about either an intermittent broken wire somewhere or corrosion on a terminal now. Going to have a go at all those things tomorrow as long as I get time.

[Glyn Harper]

So, looks like it's not working at all now.

Checked there are good connections, and it all seems fine. Good connections and low resistance on the main charge cable, and low resistance on the smaller wire that goes to the dash.

So, it's knackered I think. Not pleased, as it's only been in a year and probably used it 4 times. They only warranty them for something like 2 weeks as well.

 

[silverfrost]

Take it off Glyn and try to find a local auto electrition they normally have a right set up on a workbench to test alternators.

That way at least you will know that it is the alternator or not. May only cost you a drink for them to check it.  And if it is caput some local folks will normally recondiion far cheaper than a new unit and at least offer a decent warranty.

Or just bite the bullet and buy of the net.

[Glyn Harper]

This ones off the net, from the USA. On paper it’s a better item than the original and the place has been going years and sold loads, so it’s obviousley just got some internal fault of some kind.

I fitted a new voltage regulator but it’s stopped completely now.

Bugger. Either way it’s got to come off I guess. Horrible job as everyone who’s taken one off knows. Cut wrists and hands await. May tackle it one evening this week. I’m away next weekend so I could do with getting it to someone before then. 

Im on the Isle of Man so I’m not sure who’d do it. There used to be a little old man who was an alternator specialist and really good, but he’s packed in and probably died now. People just don’t fix things anymore. Just swap them for new parts instead. 

[Jacques]

Well, for the Isle of Man I can't say, but still, you're in the UK and they have a tradition with making everything themselves. Also alternators. Just ask here and someone will find you a propper place to have it repaired. Look on the bright side, it could be far worse.

If you bite the bullet and undo it now, wrap it up, then it's ready for shipping on Monday morning.

Meanwhile, spend the days cleaning up the engine bay, going over all bolts, nuts, rubber trims, really giving all the leather in the car a good soak in leatherique, taking the time to retighten those cloncking firewall bolts, changing oil, coolant and gear box oil and a lot more fun. It's spending quality time with your Esprit. What could possibly go wrong?

Kind regards,

Jacques

[fjmuurling]

Hi Glyn,

 if / when you take the alternator out can you measure the outside diameter of the pulley for me?

[silverfrost]

3 hours ago, Jacques said:

 

Meanwhile, spend the days cleaning up the engine bay, going over all bolts, nuts, rubber trims, really giving all the leather in the car a good soak in leatherique, taking the time to retighten those cloncking firewall bolts, changing oil, coolant and gear box oil and a lot more fun. It's spending quality time with your Esprit. What could possibly go wrong?

Kind regards,

Jacques

Jacques

That is why you do not see any esprits on the road much, we all take little bits off to repair that should take 5 minutes then it turns into a full on restoration as we all go nuts renewing and painting everything lol.

 

 

[Jacques]

And after a lengthy restoration, then some just sell the car...

Jacques

[Barrykearley]

4 hours ago, silverfrost said:

That is why you do not see any esprits on the road much, we all take little bits off to repair that should take 5 minutes then it turns into a full on restoration as we all go nuts renewing and painting everything lol.

Mines out and about most weekends all year round 

[Chillidoggy]

Yeah,  but you have a choice of two, so more chance of finding one that works.

[Barrykearley]

That’s true.....it does help matters when ones in bits

[Glyn Harper]

I don’t think I’m going to get it out today. Far too much on. Maybe this week though one evening.

and yes, I will measure the pulley.

[Barrykearley]

May I suggest removing the bulb

[Glyn Harper]

If only I’d thought of that sooner! 😂

[Barrykearley]

Piece of black insulation tape works if you don’t fancy pulling the binnacle 

[Chillidoggy]

As frustrating as it is, at least you have a conclusion to the problem.

And the perfect technical solution from Farmyard Exotics, too.

 

[Jacques]

Now, I don't know if the warning module (bulb) is reacting on a too low voltage (a threshold) or something else, but let's imagine that a single core wire inside one of the alternators stator is nroken or shorted in some way (not lacquered), then it's making too Little power to be of an good use.

On the other hand, tingering with the alternator, then seeing it working for a short while, may suggest a partially, now fully broken connector inside.

Kind regards,

Jacques

[Glyn Harper]

The supplier in the US emailed me about a soldered wire in the voltage regulator so I’ve asked for more detail as when I swapped it, the old one had nothing soldered and the new one just dropped in, and it did work properly for a while. The connections inside the regulator were soldered, but I did t have to so,dear anything myself.

It’s making no charge at all right now so I’m guessing it’s something inside it has gone.

These are recon after all. Who’s to know the recon process isn’t just brake cleaner, new voltage regulator, pop it on eBay. 😁

I’m sure they do more than that, so I guess I may have just been unlucky.

ive checked all the connections for continuity and resistance, etc, so I’m pretty certain it’s the alternator. There’s not that much to the charging circuit on an Esprit after all. It’s not computer controlled or anything.

[Glyn Harper]

They’re saying the thin wire needs to have power to tell the alternator to charge. 

I measured the thin wire while it was connected and the engine running and it only showed 2 volts. Should that be showing more than 12?

i thought a test would be to disconnect my thin wire (to protect the instruments) then supply 12v directly from the battery to the thin wire terminal as a test to see if it charges. Does that sound like a good test?

Where does that thin wire get its power from? Wonder if I have a sticky relay or something, and the alternator is actually fine. 

[silverfrost]

I normally get anthing  varying around 13.4v  at the battery when the engine is running !  

 

 

[johnpwalsh]

Let me start by saying. I hate electrical stuff, but I once had an issue with the small wire ( white with Brown stripe I think) it had broken internally and then gave a small charge reading.

[Glyn Harper]

I'm definitely only seeing about 2v on that smaller brown wire.

When I disconnect it, I do get continuity to earth. Not sure what it's meant to do though, whether it's meant to be a higher voltage to initiate charging. It could be a fault up the wire, but it does give 2v when charging and ground when disconnected. I suppose that could indicate a short.. I'm just not sure what that wire is meant to read.

[LotuStuart]

7 hours ago, Glyn Harper said:

i thought a test would be to disconnect my thin wire (to protect the instruments) then supply 12v directly from the battery to the thin wire terminal as a test to see if it charges. Does that sound like a good test?

yes. Try this (*Sigh* for liability reasons at your own risk) but yes, this would be a good test, and then running a new wire from an ignition positive wire would be a fix if you can't face tracing the wire back to find the issue.

BUT do you have a wiring diagram? Worth checking that first as it is odd to be 2v or ground!

[Glyn Harper]

I've just spoken to a pal of mine who's a good engineer, (and owns a Lotus) and he's given me a bit of info on the exciter wire.

So basically, the dashboard will have a 12v feed to the bulb. This then has a wire going to the alternator. When the alternator isn't charing, the exciter connection acts like a ground, so the battery light comes on. (powered from the dash).

But when the alternator is charging, it provides 12v down that wire. The bulb then has the same 12v at either side, so doesn't light.

So he's suggested running a wire from the battery, to a bulb, then to the alternator to simulate what's going on in the dashboard.

So it's possible there is a wiring problem with that circuit, I'll check tonight and see. It's off that there is 2v though.. although if there is a short somewhere I guess this could cause this to happen maybe as the voltage leaks to earth.

Finding that wiring problem will be another issue! But at least it's a start. At least I could bypass it for the time being if that is the problem.

So yes Stuart, you've come to the same test process I have having spoken to my friend.

I do indeed have a wiring diagram, so I'll consult that now. Cheers.

[Glyn Harper]

So going on from this, the fact it was charging intermittently before.. wondering if my problem is my start dropout relay is a bit sticky? Could account for it going on/off, and only coming on when the voltage was dropping below a certain amount, and things like that, when the voltage for the energiser in the relay coil wasn't enough to keep to open or closed. Sound possible?