No charge light on

But it's charging fine .I have a second unit that monitors charging and that says green .It is reading 14.2 at the battery @1200 rpm ,no load , and with load ,full beam wipers etc it reading 13.8 @2000 rpm .
What next ??

What next ??

Hi Lee

I have just had a look at the charging cct, although it is for an Atmo, but I suspect it is very similar to the Turbo. I note that there is a 5 amp fuse that feeds the instrument panel, which appears to be the feed to the charging light. The actual charge current goes from the alt, via the starter, to the batt, so that is why you are charging is ok. However I suspect that if this fuse has gone other functions of the instrument pannel/warning lights may not also be functioning. Just one question, has the light functioned correctly with your other charging monitor in circuit previously?

John

Fuse is fine ,instruments all OK .The warning lights are earthed through a diode on the back of the board behind the lights .It comes on with ignition so that's OK .My intercooler mist is switched and wired through the old engine bay fans so the warning light for that comes on when I push the switch ,this has never caused a problem .
Been working fine before with the double lighter socket/monitor .Only thing I've done is change the trigger sensor and I have had a power inverter plugged in to charge my phone and run the laptop .But I've done that before with no issues also .......

This is a difficult one then, because the function of this lamp detects a change of voltage, ie:- Light on 12volts, Light off 13volts ish, not just a simple volts on/off situation. My son has just popped in for a cup of tea, he is a trained Alfa/Fiat mechanic (and 155 owner), and he asks if the lamp is at full brightness all the time, or is it a bit dimmer on tickover, and gets a bit brighter as you rev up?

Light is bright ,doesn't alter with revs .

I shall eet-itt wis ze ammer oui ??

But its not a broken wire or a wire off some where ?

Checked at the alt .Reg wires are ok ,earth is to fuel pump and good also .Big red wire fine ,engine and bat earths all good .

After a big discussion, we feel that you need to have the alt checked, as according to the cct, there is a two pin connector on the back of the alt which runs up to the instrument panel, seperate from the fused cct, this could have the charge voltage on it to put the lamp out. Just might be worth checking this connector.

ahhh rite now !!
Put a meter direct to those two wires at the alt and I get 5.8 but it's still 14.2 at the bat .If I pull the wires the warning light goes out but I get no charge at the bat it's reading 12.1v .Put the wires back and it's 14.2 at the bat again but the warning lights back on .
I've got another alternator here ,not sure of it's condition though .I will take it with me to Mallory on Saturday just in case .But it's reading 14.2 at the bat ,it is charging and I got back from Leicester 40 odd miles with the light on .......

Sounds to me like the error light function has popped in the alternator. I've seen this before where the battery light was on constantly but the alternator regulated just fine.

Older alternators like the motorola used in the DeLorean use the lamp circuit to regulate the charge current (famous because if the bulb fails, the alternator stops charging ). The newer Valeo alternators and Ducelliers found on some early Renaults and DeLoreans, have the two pin plug. One is the feed to the dash lamp, the other is an ignition fed 12v. The alternator regulates using the 12v feed, and lights the light if there's a problem, eg when you first turn the ignition on, engine not turning.

My suggestion would be to either gert an alt on exhcange from Renault (recently gone up to £160), or invest in an aftermarket voltage gauge. That'll set your mind at ease that the alternator's performing as it should - for example as you switch the lights on, you shuold see the needle dip for a fraction of a second, then move back up to where it was.

Of course it's probably worth testing continuity from alternator to dash, and the bulb itself. The bulb connection is the larger of the two pins.

Cheers Martin .I have a gauge of sorts with the twin ciggy adapter .It has three led , go red amber green .It's been lighting up all three ,that shows it's charging .

Update .....one wire to earth gives 14.1 and the other gives 8.5 so that solves that .I should put the cooling ducting on the alt as that may be an issue also .

Lee, sorry I disapeared, I had an unexpected visitor, and had to be sociable for a while But yes I agree with Martin, the attenator could well be the prob, I would get it checked out.

Not to worry Jon .All adds to the knowledge base innit .

Lee, One time I drove my car with the alternator wires off (by mistake).
It ran for 70-80 miles, no dash light and then under boost it started to stutter a lot. After another 5 miles of limping along it died.
re-connected the alt, and with a push start it was fine.