Electrical blackout

[lomh 13]

Hello, I need your help.
I am far from my garage and my workshop documentation and I have an electrical fault.
The first symptom was the voltmeter on the dashboard which showed 0, but the car ran and started normally.
After 60 miles it wouldn't start.
All the dashboard lights and car lamps go out when I turn on the ignition or turn on the headlights.
I replaced the battery with no success.
Could you give me the location of the different groundings ?
I know there is one in the center of the boot, but it is OK

[HCA]

How do you know the ground is ok?

As you describe the situation, it is a case of your main earth or battery terminals at fault. Carefully check these three points before looking elsewhere. Once these arr checked, look at the terminals on the solenoid.

[lomh 13]

Thank you for your reply.
I have checked this terminal, cleaning the contacts of all the wires there.
Is there an other earthing terminal in the car ?. I have found the electric diagram.but the earthing of all the device are individualy drawn.

[HCA]

OK, good, you have cleaned all the connections - were they corroded?

I cannot help you on exact earth positions as I do not use the earth system on my car. I am interested in the earth that the negative battery cable goes to - this sounds to me the culprit as the headlamps and panel lights fo not share an earth point. Give this a good clean and reconnect. Battery terminals are clean and good connection? As are the terminals on the solenoid? If these are good, move onto the engine earth strap.

With all the above good, the car should at least start!

One thing, actually two, when you say the car does not start - is there at least a clunk from the solenoid, or is there just silence? And importantly, you are sure the battery is in tip top condition?

[lomh 13]

When I turn on the ignition key, the light on the dash goes out the same when I use the horn or any electrical device.
Sometime they don't go out, but when I turn the key for cranking, I heard a little noise from the solenoid and light goes out.
This afternoon, I'll pull the car In a garage, because outdoor there is a strong wind today. It is difficult to have the bonnet or the doors opened

[HCA]

When I ripped out my wiring, I remember an earth on the chassis at the front and one behind the dash on the tunnel. But I still think it is the main earth or the engine strap.
Si vous voulez, appellez moi au zero six vingt-sept seize seize vingt-quatre.

[HCA]

Is there anyone who knows where all the earth points on a +2 (S130) reading this? Will you chip in and point out where they are exactly please?

I am in contact with the OP and he definitely has earthing issues and is going to clean them all up one by one. Unfortunately I do not use the chassis earth on my car, so I do not have a clue! I cannot even remember where the engine earth strap is!

Thanks!

[RichardHawkins]

I think there is a large earth on the exhaust side of the engine by the engine mount that attaches to the chassis.

Hope this helps,

Richard Hawkins

[mbell]

There earths on the body to chassis bolts for both front towers, under dash one to the dash bracket, earths to the rear chassis mount (as well as battery earth connection), steering earths via one of the mounting bolts. Also the engine earth as mentioned.

[HCA]

Thanks Richard and mbell !

Robert - all of these earths should be cleaned especially the engine earth (apologies, I gave you the wrong side to look)

Maybe call tomorrow,

[Bud English]

The chassis end of the negative battery cable is notorious for being unreliable due to it's location at the diff mount. It makes it hard to inspect for corrosion and ensure a good earth connection. More that a few +2 owners have moved this terminal to one of the cross brace bolts on the rear tower to get it away from moisture exposure and above the battery fumes.

[alan.barker]

Remove the set screw earth that goes through chassis flange into bobbin complet.
Clean thread in bobbin with Tap, wire brush all parts, nice and shiney.
Alan

[elans3]

I have exactly the same issue on my Alfa Giuia ('63) (Imalso have an Elan). Battery is good, & holding 12.65 volts. All battery connections and main battery and engine earth points are clean, tight & dry.
Renewed starter motor, (Bosch), ign switch (Bosch), and the cable from the ign switch to the starter solenoid.
All I get when I turn the key to crank, is a little noise from the solenoid (not even a clack), the fuel gauge returns to zero, and the electric petrol pump stops ticking. I've jumped the starter solenoid direct to the battery and the same thing happens. I've jumped direct from the starter main battery connection to the solenoid, and just the same.....
is there any other earth point that I could have missed ? Does the gearbox need an earth like the engine ?

Up to a week ago it has been 100% reliable for 5 years, starting and running beautifully.

I'm lost now, can't think of anything else.

Any thoughts ?

[alanr]

You say the Battery shows 12.65 volts which I think is a bit marginal. However, with a Voltmeter across the battery terminals, everything all connected up, what happens to the 12.65v voltmeter reading when you turn the ignition key?

Alan.

[HCA]

Your base problem is that battery power is unable to get to the ancilliaries, either through the positive or return through the negative.

You say that everything is clean and tight. You might think so, but something somewhere is not. It will be difficult to pinpoint the culprit from an armchair beyond the obvious connections.

If your gearbox is connected to your engine without an insulating gasket, then generally you should not need an earth - providing the engine earth is good and robust.

12.6V is considered a good average for a healthy battery, so your 12.65 is ok.

Sorry, but you will have to look at all your connections again - when you have them totally clean, smear some Vaseline on them before tightening.