Battery light/not charging issue

[hendrix]

Recently have bought a 1.2 Antibes with a few issues (not counting almost terminal tinworm).

The main issue at the moment is the battery isn't charging at all, alternator was swapped for a known good unit and still the same problem.


The battery light is on at idle but when the car is revved it goes out - you have to rev it harder the more the engine is run.
The rev counter fluctuates if you put the indicators on or headlights.
Fuel gauge goes down until you rev it upon which it will return to the right level
When you switch the car off and take the key out the battery light comes on. flashing the headlights will turn this off.
No battery light illuminated when ignition is turned to II before cranking.


Any ideas?? I have noticed a wire with a spade end disconnected on the bottom left of the coil as you look at it from the drivers side.

Thanks.

[mowgli]

normally, i'd say the alternator is goosed. but i think you have an issue with an earth or maybe the pcb on the dash.

[Jonesfach]

Thinking out load here..

sounds like you you have a major drain/short

by reving engine you are increasing the voltage output to max about 14v on battery, thus light will go out..this explains why it would go out. So as you have tried a trusted alternator I suspect the charging system is ok....

i am am guessing the battery does not run down without ignition on....so it is something that is only powered from position 1/2 on switch. Ie not lights as these are powered all the time through the switch. Don't know about full beam on headlights does ignition need to be on?? That may be a clue with the headlight flash after you have taken the key out?

personally I would remove a fuse at a time from the fuse box and start her up. If you have gone through all the fusebox to no avail then check all earths around the car. Especially those to do with the engine first...

unless someone has has heard of this problem before ? Best of luck

i am am electrician but not an auto spark(different world) so am just thinking logically.

[Jonesfach]

normally, i'd say the alternator is goosed. but i think you have an issue with an earth or maybe the pcb on the dash.

Good shout the pcb....try that fuse first??

alternator does seem to be doing what it should, although without having the voltage readings won't know for sure.

do you have a voltmeter at all?

[hendrix]

Yeah I've checked it with a voltmeter. The strange thing is, the battery light goes out when revving but the battery voltage remains a constant 11.9v.
gonna try a wire from positive on battery to the small alternator wire, maybe that will 'wake' it.
Other than that I need some more mk1 clocks to try

[hendrix]

Will also try the fuses. Good shout cheers.
Im guessing that given how rotten the car is, it's likely to be an earth.
any ideas on the unattached wire off the coil?

[Jonesfach]

Yeah I've checked it with a voltmeter. The strange thing is, the battery light goes out when revving but the battery voltage remains a constant 11.9v.
gonna try a wire from positive on battery to the small alternator wire, maybe that will 'wake' it.
Other than that I need some more mk1 clocks to try
11.9 v is not right. Disconnect the battery and see if it is any higher. A good battery I think from distant memory 13.2 v
then when running should see about 1 v more. 14.4 or so
would not try the wake it idea yet ? Might blow something up....
you should be able to check the back of the clocks. Look for signs of melting on the pcb..

[Jonesfach]

Will also try the fuses. Good shout cheers.
Im guessing that given how rotten the car is, it's likely to be an earth.
any ideas on the unattached wire off the coil?
of course very likely an earth fault. Is it like a pear?
no idea on the unattached cable....I take it, it is taped up and not shorting out on the bodywork !

[Balley]

Clean up the battery lead to both the alternator and the battery, also clean the earth point on the alternator and clean all other earth leads. Use some 80grit sand paper.

as Mowgli says check the circuit on the clocks. Sounds like a bad connection some where to me.

Is there an ignition feed to the alternator? should be.

make sure you have a full battery voltage at the battery too on the battery lead.

[hendrix]

It's very rotten haha.
its not taped up, just a spade connector not connected. I'm off out to work on it in a minute so will report back on colour and what the other end is connected to.
ill check the earths again too. The alternator earth appears to be connected to an oily inlet manifold lol
i need to push the speedo cable through a bit more to get clocks out far enough

[hendrix]

dan, all wires on the starter loom
except black with yellow trace are connected. That one is taped up as iirc it's for auto choke

[hendrix]

Ok so just come in from outside.

changed the clocks, made no difference.
checked the coil wire. It's a switched live that appears to be spliced off the main loom
changed the battery for one off my xe. Reads 12.6v, made no change.
checked voltage between battery and small wire on alternator, it has a voltage comparable to that across the battery so obviously receiving power
what I did notice with the new battery is when you turn the ignition off, the light remains on regardless.
Haven't checked earths to gesrbox yet but put a jump lead on to -ve from engine.

[hendrix]

Maybe check wiring around the ignition?