gazzaull22

Hi all please can anyone help? I have a 2000 plate ford escort 55 van, the problem is the battery light has come on, I checked the power accros the battery terminals while the van was running and i was only getting 12.5v with engine runing.

So i have changed the alternator for a brand new one, the belt looked ok so i never changed it, i checked the voltage again and its still the same.

I have checked the fuse box for any problems but everything seems ok, i have put the thin blue wire coming from the alternator onto a + connection and the charging light goes out.

Please can anyone advise what else i need to check?

P.s my knowledge of cars or van is limited lol

Thanks

Gary

martysmartie

iTrader: (1)

It sounds to me as if you got another duff alternator or it could be the regulator, you got it right with the cable as usually when running the D terminal gives out +13V and so two lives at the bulb hence it extinguishes at the moment it's not giving out charge so that terminal is an earth and so the bulb lights indicating no charge.

Normally what happens is the blue wire breaks and so you have no bulb at all which can stop it starting as the bulb is actually part of the charging circuit which excites the field windings which starts the charging.

Martin

gazzaull22

I think thats where i have gone wrong i fitted the thin blue cable to terminal w on alternator as this was the only one the nut would fit 8mm and from what you saying it should fit onto the d+ terminal?

And this mistake would stop it from charging?

I think this problem has happened before as there has been a few wires chopped etc but everything else works fine.


Thanks for your help

tabetha

The thin blue wire does go on to the "W" terminal, W meaning warning(light).
tabetha

gazzaull22

Hi i have wiried the alternator up now and put the thin blue wire to the D terminal and the van is now charging and battery light comes on the goes off thanks all

martysmartie

iTrader: (1)

No problem glad it's sorted, that will be why then. Tabetha I think you have got confused with voltage regulators as W does stand for what you said on them. W is an 8V output for rev counters on Diesels etc on the alt.

As I say that light is a crucial part of the charging circuit, as you have found out, although you wouldn't think it unless you understand how alternator's work. Out of interest revving to around 4K would have started charging as well

Martin