Hi people, nice forum.

I've got a question that i've probably already answered myself but would like conformation from someone more tech minded.

I'm having a charging problem, the battery isn't charging, i changed the battery and still had the problem so suspected the alternator, on examining it i found the little blue wire had snapped off the spade connector, this is on a escort diesel 55 van, 1800.
There's only 2 wires, the main cable connected with a nut and a little blue one that's connected with the spade connector.

Do you reckon this was my problem. ?
I've read through a few posts the search threw up and i can't find anything specific to the diesel alternator but did see a post saying the blue wire is only for a back light bulb or something, is this the same on my diesel. ?

Sorry for the seemingly silly question but i've a long trip coming up and don't want to be left stranded.

Cheers.

 

The blue wire is connected through a bulb, the other side of that bulb goes live when the ignition is turned on to "run", as the alternator is not yet turning the stud onto which the blue wire goes is earth, this causes the bulb to light, once turning(engine started) this pole goes live, and of course puts the bulb out as the earth for the bulb dissapears so is important.
However if you get stuck simply rev to around 3500 or so and the alternator will kick in and start charging even without the blue wire on, as it is redundant when running.
The live through the bulb is used to excite the field windings in the alternator to initiate charging(once turning) but without the wire there is enough residual magnetism present in the alt to do the same when revved to around 3500/4000, another quick way is to just flick a live onto the blue wires terminal post once running.
Can check easily put headlights on, and watch against a wall the light will get slightly brighter when revs are raised from idle.
tabetha

 

Thanks for the reply Tabetha, are you saying the blue wire being not connected could have been the reason by battery wasn't charging. ?

Thanks.

 

Yes it would have prevented it charging, not having a blue wire(and working bulb) if you didn't go over about 3500/4000 rpm so that it kicked in without the blue wire.

 

Thanks for clearing that up for me Tabetha, and thanks once again for your help.

 

No probs matey, I used to live in sheffield, on MANOR TOP as it was then, in the early 70's, dad was in the army, but I gather it has changed a bit now!!
tabetha

 

Really. !
I'm down the road on the Wybourn.
The Manor has changed a lot, for the better imo.

 

I was only about 3 or 4 my dad said so that would be late 60's, showing my age here!!
tabetha