Hello! I have another question from my UNO 1.1 i.e.!!!
I have the battery light which is always ON. When engine is OFF, the light is very bright (and this is correct), but when I start the engine, the lamp does not cut off, it only reduces its intensity.
This fact started approx three years ago (!) and it was very very rare: only once time a month I could see a very poor light and only for some seconds (only by night because the light was very poor). Then it became more frequent, and now I see the light continuatively ON (but with a poor light). I checked battery voltage which is 14.4 V when engine is ON (is it high? I thought it had to be not more than 14V). However the light is more bright if I turn on electrical stuff as "glasses electrical workers" (can't say better in English) or external lighs. Also battery tension diminuishes if I turn on this electrical (but I think it's a normal fact dued to more current consumption and I never saw this tension run under 12 V also with all electrical ON).
Now I ask if this indicates a developing problem (I hope not to remain with a cut out battery!!!) or if there is something simple to check, as diodes of alternator. However it's not an important problem because battery never discharged. I only want to avoid to completely burn my alternator or regulator or other electrical/electronics caused by a short circuit in charging system!
Thanks you very much,
Andrea.

I had the dimly-glowing light on my Uno 60 and (you won't believe this!) it went away when I changed the instrument cluster (which I was doing anyway because I wanted a tachometer that the Uno 70 cluster provided). I think it may be something to do with a diode (or maybe a resistor) on the back of the instrument cluster.

The 14.4V at the battery sounds exactly right, so I doubt you will get stuck with a flat battery.

If I was in your position I would arrange to try another instrument cluster (borrow from a friend or specialist/buy one from a wrecker's) and see if that cures it.

Thanks,
-Alex

OK...
But are you sure that the new instruments cluster has a working battery lamp ? When you turn the ignition key can you see the lam to turn ON?
However I 'll try to check connections on the back of control panel... it' s not so simple to find a complete cluster at low price here in Italy!!!

Yes, my replacement cluster (from Uno 70) had a light that came on fine, and stayed off when it should.

It's an interesting concept, not being able to get hold of another cluster for testing purposes. I mean, I've only got four or five available to me without going to the wreckers and I always dreamed that Italy would be the home of FIAT wreckers!

Good luck!
-Alex

Yes... here in Italy is quite expensive to buy some car used parts!! I payed 15 euro (approx 18 US dollars) for the canister valve this summer!
Thanks, Andrea.

I had that SAME problem with my car, it turned out to be diodes in alternator!!

Battery lamp and Idol

Hi there andre79ge,

Did you ever get to the bottom of it by replacing the cluster?

Firstly, my “Battery Recharging Warning Light” {102 (L) on my attachment on https://www.fiatforum.com/attachment.php?attachmentid=1294

} is always off with key at OFF position, not sure what you mean by “When engine is OFF, the light is very bright (and this is correct)” do you mean with engine off including when key removed, as this is wrong (3 UNOs – 8 Years), or only (fully) on with key at MAR and engine not running which is right.

I have had different charging problems on my first 903 UNO. They only affected the normal operation, with key at MAR, comparing if engine running or not running (2 bits, 4 Outcomes). (About 90% sure reasons were this way round).

1). (0-0) the charging light not lit both with and without engine running. This happens when the drive (fan) belt snaps or slips off. If belt not replaced, battery goes flat soon after.

2). (1-1) Charging lamp lit with and without engine running. This began after carelessly spilling engine oil into the alternator while filling, rapidly followed by a flat battery (brushes killed). An alternator from breakers yard fixed that one (and a funnel/more care to filling oil there after).

There can only be 2 other “steady state” outcomes:

(1-0) is the correct operation when bulb is lit only at MAR when engine is not running and not lit when engine is running (battery charging with engine running).

(0-1) light not lit with engine not running, but lit with the engine running. I don’t know what it would represent (if possible).

Your problem is in between (1-0) and (1-1) - bulb partly lit with engine running but battery seems to charge, and worse (brighter) when using more electrics (rear heated window, fag lighter and lights).

What condition is the alternator in terms of current output (A) [not voltage (V)]? Could it signal a low alternator output (alternator on way out) [especially at Idol (slower turning alternator)]

Dose the lamp fade at all when the engine has been running for some time (when your engine starts to idol smoothly), and the alternator + battery has warmed/charged up? (It may not).

If there is less charge in the battery, the voltage can drop (higher battery internal impedance) and perhaps it could affect the ECU, and the Lambada sensor reading (and all other electrics). This may be another link to poor alternator performance. Later alternators have a cooling pipe fitted to the back – is yours OK? If it is ok try another alternator and hopefully the idol will sort its self out.

Lastly,

If when you changed vacuum advance, did you check its hose for leeks?

I Hope this helps!!! I am on car expert

, but OK at electronics

.

Louie Bee.

Hello!
Thanks for your clear and precise explanation! I think you was very direct in what you wrote, and I appreciate it a lot! I'm not a technician but I like this way of analyze problems!
However I tkink that my alternator problem is a diode problem (probably one of the diodes is interrupted). Infact my charging problem is what you described in your writings (inbetween (1-0) and (1-1) conditions):

Battery lamp is bright with ignition key ON and motor not working;
It is very poor lighting when engine is running (when the lamp 'd be completely OFF);
This lamp increments its light if I turn ON some high current job such as fan, lights...

But I think the current charge is OK for charge battery. I can't measure charge current because I haven't an amperometer which measures 30 - 40 A currents, but I can measure battery voltage which is over 14 V when engine works (also at idle). The voltage drops when I turn ON two or more high current jobs, and it' s possibly an alternator fault (it produces a good current but not at its maximum performance). However I 'll try to check battery voltage in the first minutes of running in order to see if there' s a link with idle problems, but I think not.
However I' ll try do disassemble the alternator/regulator/diodes group in order to check them!
I also thought that alternator could take too muck torque from the engine causing idle problems (but it's only a very fantasy idea...).

I did not completely controlled vacuum advance hose because it goes under air filter/injector groups and so I could not check it completely. However I checked the "power" of its vacuum by putting a fìnger on its hole and I could feel the vacuum (it is high at idle and it diminuishes by doing a hard aperture on throttle position, I think it' s correct). So vacuum is present but I can't be sure that that hose is completely OK. However I think that it's a very poor and almost negligible air leak because the vacuum is good!
Another time very thanks a lot for your help,
Andrea.

I think you are right to rule out a link to a poor alternator/idling problems. If the battery was getting too low, the battery would not be holding enough power to restart car, and drawing more current (headlights etc) would prob then make the engine idol worse (was a bit late last night – sorry)
Some sort of half wave reification only going on with a diode or two fried on bridge do you think?
(vacuum problem on your other thread)

Louie Bee.

Take the bulb out.

Finally my grandfather had... I don't know how to say it in English, however he went with my car on another car crashing both of them.
My car had an external light broken (both glass and supports), engine cover (can't explain it with the correct word, however it's the cover that you have to pull up if you want to see engine's zone) and also "front bumper" (the black/brown plastic part in front of the car) and lateral chassis (over the left wheel). So my parents decided to leave the car and take a new one because technicians want one thousand euros for repair it...
Not happy for this decision!!!
I' m starting to think to repair it by myself, buying chassis parts by second hand in order to get them cheap!!!
So I can't say anything new about idle problems and battery charging.
I hope to have the possibility to take another look on that problems. In other words... I hope my parents don't decide to completely demolish my old UNO!!! I like it a lot...
Hope to reply on this forum another time...