75 TS electrical problem

[alanm]

Hi all

After 12 months of impeccable service my 75 has a problem – it won't start .

Clues for those more knowledgeable than myself:

Sunday
First sign of problems – slower crank than usual on cold start.
Nothing at all on second (warm) start, half an hour later. Started okay after tightening the battery terminals (fluke?).

Monday morning
Slower crank on start up then runs erratically, engine revs fluctuating up and down, say 400rpm, then 900 etc
I switched the engine off and tightened the terminals again. The result of this was no crank at all and radio goes off if I switch the headlights on.

Tonight
Battery shows green light (healthy battery if it is to be trusted). Neighbour tests it with box with wires attached and pronounces it healthy.
Modify battery terminals so that they can be tightened PROPERLY.
Clean terminals with terminal wire brush.
Try to start car with great confidence – NOTHING!!
No dashboard lights, radio works... until I put the headlights on, then the radio goes off.
Have traced earth cable to engine and body and they seem okay.

Is it possible that the battery is NOT okay even though it says it is okay?
Do you guys know of any other reason for the problem?

Any ideas welcome, trying to avoid the RACV visit followed by tow truck.

Cheers
Alan

[GTVeloce]

My battery died recently and showed some similar signs. It also still had the "green light" and showed sufficient voltage, however, it was actually dead. As somebody explained to me the plates inside the battery had collapsed so when you try to draw current it isn't able to properly.

If you can get hold of another battery (even if it's not new) i'd try that first. I bought a new battery and everything has worked fine since.

[colcol]

Sometimes you can clean the battery terminals and the clamps on the cables on the battery terminals, all to no avail, try starting it, by cranking the engine over a few times, and see if the battery leads, where they are clamped onto the battery terminals are getting hot, if they are it usually means a bad connection in the terminal clamp, where the wire goes into the terminal, you may need to go to Repco and get some new battery terminals, they corrode pretty bad there, and the Alfa Romeo battery clamps are nothing to write home about, if they are ok, try the battery lead  + to starter motor +, that carries a lot of current, pull it off and give it a good clean, and see how you go, Colin.

[alanm]

Thanks guys,

Tuesday morning:
The most feeble of cranking, then nothing.
My gut feel is that the battery is dead, so I just called the RACV Battery service.
I'm a member so I figure I may as well get some value.

GTVeloce, I did a little online research on the green light, they do sometimes lie.
Colin, I reckon I have done a good job of the terminals so I will have a look at the battery lead to starter motor if the battery turns out to be okay.

Thanks again guys,
Alan

[alanm]

The wrap up.

Battery pronounced dead – not rechargeable.
Cause, alternator failure.

Next question will be second hand alternator or reconditioned unit. Mmmmm.

Alan

[shiny_car]

Could be worth having an autoelectrician assess the alternator. It may only be the voltage regulator that has died, and these are easy to replace (genuine Bosch can be <$100 for the part).

[AikenDrum105]

Or just the brushes    < $20 

[Mat Francis]

Depending on where you're located, I reckon Maroondah auto electrics is the go. Fletcher is his name, really nice guy. I drop my alternators down to him. New brushes, new regulator, $130 including labour (about a year ago). As long as the bearings are good, I daresay that you'll never have to touch it again.

[festy]

If the battery has been damaged by a faulty alternator, it sounds like you may have a rectifier diode issue.
Dodgy brushes will prevent the battery from charging properly, but an alternator pumping AC into the battery will kill it.

[colcol]

If the brushes are undersize and worn out, it is usually cheaper and quicker to just replace the whole voltage regulator, a faulty Alternator will fry your battery and unluckily your engine computer, have the alternator looked at, take it out of the car, and take it to an auto electrician, don't drive it there, and risk blowing up the computer, while the alternator is apart, get new bearings put in, although, if you get a changeover alternator, it should have new bearings, Colin.

[alanm]

Thanks guys,

With your words of wisdom and a little time I would have been encouraged to remove the alternator and take it to an auto electrician.
The RACV offered to organise a free tow straight away and I took him up on the offer. The car is now with one of our club sponsors who I am guessing will test the alternator to establish where the fault is.

I will post a message with the final diagnosis today or tomorrow.

Thanks for you inputs, this forum is a fantastic resource!!

Alan

[alanm]

Hi all,

The final wrap-up.
Reconditioned alternator, car starts like dream.

An intermittent problem that I thought I had with the ignition switch has gone.
Battery or battery terminals? I will never know.

Cheers,
Alan.

[shiny_car]

Good to hear. Thanks for updating.