Regular readers will remember that we have just had a new alternator fitted.

Shortly after a new fault developed whereby after starting the car the battery warning light would not extinguish. However, tests showed the alternator was working ok.

However, if you turn the ignition on, and then off, and then back on again, and then start the car battery light goes out ok.

Now a new problem has developed: the battery warning light now flashes on and off whilst driving.

The conclusion of the auto electrician is that the body computer is f*ck*d and is sending duff info to dash. A new computer is £300 (which when you consider you can buy a whole laptop for £250 seems a bit steep).

There are second hand ones on ebay but the auto electrician (who is ex FIAT) claims they can not be virginised are as such are useless.]

What are your thoughts (hoping S130 is looking here as this seems right up his street).



P.S.: There are no fault codes showing on the ECU diagnosis.

So what signal is the alternator sending to the body computer? Is it a genuine OEM alternator? A lot of cheaper pattern parts are known not the send the correct signals

Grrrr

Yes I'm here. Was in the middle of posting and looking at eLearn and lost all my post!

There are only three wires at the alternator end. Ground/chassis/casing strap, +ve output to battery and +D sense wire. The sense wire goes to the body computer via a major connector.

Suggest you check all the alternator connections, engine earth strap and the battery connection. (loose, corroded etc.)

The procedure from eLearn for stesting the alternator sense is a follows:

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Connect the Examiner in Voltmeter mode with the positive terminal to terminal D+ of the alternator and the negative earthed

With the ignition on, ensure that the measured voltage is less than 5.5 Volt and that the generator warning light on the panel is on

If the voltage is interrupted, the alternator is inefficient and should be replaced

Start the engine and check, with voltage D+ greater than 5.5 Volt, that the generator warning light on the panel goes off and a correct battery recharging indication is displayed.
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You should also check with a voltmeter the alternator output voltage and battery voltage. Both should be around 12V with engine stopped and about 13.6 with engine running.

could it be a faulty diode in the alternator?

I'm hoping a faulty diode or other connection issue can be isolated with proper testing. To point a finger at the body computer,especially after an alternator replacement and the associated wiring loom displacement required for an alternator change is far more likely to be the problem.

THanks guys for your input. Will let you know how things go.

smelt a burning smell when i got home just now, had lunch went to go out and pick up a punto mk1 gearbox and battery light was on, got meter out got 12.40v in battery but goes down to 11.85v when engine running, looks like i need alternator

Radlet6 said:

Shortly after a new fault developed whereby after starting the car the battery warning light would not extinguish. However, tests showed the alternator was working ok.

However, if you turn the ignition on, and then off, and then back on again, and then start the car battery light goes out ok.

Now a new problem has developed: the battery warning light now flashes on and off whilst driving.

Click to expand...

I had exactly the same thing happen about 3 years ago after having a new alternator fitted (see my original post)

https://www.fiatforum.com/croma-ii/221953-croma-electrical-alternator-problems.html

After much head scratching, the fiat Dealership told me the same as you, i.e. that it was most likely the computer. It is still exactly the same to this day. Although its annoying, as I've had no other related problems, I've left it as it is. I think it was a reconditioned alternator they fitted to mine. I'm afraid I don't have the technical expertise to shed any more light on it but please do let us know if you find a solution.

Just wondering if you ever got to the bottom of this problem with the battery light, as I have had exactly the same issue now for about 3 years.

Sorry that it's been a while since I've been here but busy times etc.

Still have my Croma (coming up 7 years now) and plan to keep it another two at least - having just spent £2k on having the gearbox rebuilt.

Now you all might think this is a lot for a car with a trade in value of £1300 (yes I took it in to find out - told the guy it was worth more than that in spare parts - or words to that effect, I think "off" appeared in my vocab somewhere).

It's still sub 63K on the mileage and there is nowt else wrong with it. If I had taken the £1300 and added £2k to it what would I be able to buy? Not anything as nice as the Croma.

The alternator problem was solved by fitting a new alternator, but when I had the old one bench tested it showed no problems at all. It was sending the correct signal and was charging just fine.

I have now put this up on ebay if anyone is interested.

Oh the Croma!

What a lovely but difficult vehicle to get to grips with come mechanics, longevity, reliability etc.

There is no doubt that the car has a very strong Fiat engine, suffers from GM additions, BUT for most of us was a cracking good buy. I paid £12K band new for mine, £6500 below list price.

I'm at 6x,000 miles from new and dreading the next "hiccup" which is possibly going to be the thermostat. Not a great expense (parts less than £30) but never the less yet another inconvenience.

But as you say regardless of alternator, gearbox, etc. costs (I spent near on £1500 pounds after the clutch pressure plate assembly failed and left me stranded at Dover docks) the Croma is a very interesting reliability/cost/lovability/wantability/not easily replaced etc. beast.

Thankfully 5 to 8 years on the Croma trade/resale value is peanuts, cost to replace is very expensive (and Fiat don't have a current alternative) so as you say spending £1000+ can/could be a very cost effective expense assuming there are no other large expenses on the horizon.

On the horizon point who knows? Fingers crossed!

I keep spending a bloody fortune on mine, but in dribs and drabs. I daren't add it up.

If, on the 1st January, a printout came out of the dashboard saying what this year's expenses will be, I'd probably immediately scrap it. But it doesn't, it keeps torturing me - just this one more repair, then everything will be fine... until the next one.

Dear Doofer-- Have faith-- faith can move mountains, she is a very big girl

Doofer said:

I keep spending a bloody fortune on mine, but in dribs and drabs. I daren't add it up.

If, on the 1st January, a printout came out of the dashboard saying what this year's expenses will be, I'd probably immediately scrap it. But it doesn't, it keeps torturing me - just this one more repair, then everything will be fine... until the next one.

Click to expand...

You should have bought a 2.4! Most of the problems seem to affect the 1.9 more

Easier said than done. There were only 38 examples imported intotheUK. The vast majority are the 1.9 diesel.

Only 34 left!