Was out driving & the Voltmeter dropped to 10.5 v.
The alternator is almost new & at this stage i dont think its Duff. I get 11.5v across Battery so no charge. Have noticed Red battery light in car does not come on when ignition is switched on will it work if bulb is gone.
What does the small wire supply to the Alternator & what happens if tis is broken somewhere. Mark & I aint up on this aspect & time is running out for 5TH gear. Need to find out tomorrow whats gone duff as Mark wants to test it on Monday. Anyone post up the circuit.
Thanks & hope an electrical guru can help as ive only ever changed the Alternator.
Rod

 

Rod check the small blue wire going to the alternator and make sure it is making the circuit! If it isn't the alt light won't come on and it won't be charging.

 

as spadge says !!!!

same if the bulb is gone in the clocks

 

the red light is part of the alternator curcuit. nicknamed exciter wire, i think it gets the diodes working in the alternator. my rs had this on for a short while and it would not charge untill intill it hit 2700 rpm then the light would go out. normally blue wire out of alternator is the warning light wire (exciter)

or maybe your alternator is fooked, new ones break too, belive me.

 

If the bulb DOESN'T work on the dash in a Cossie then it WONT charge as it NEEDS to be to make a circuit

 

Thanks Spadge this is what Mark thinks but he aint sure, so thats why i am asking, where does it go too just i have to put a new wire in.
Ive been fitting a new heatshield to the Alternator today so may have pinched or broken this wire its dark & a bit late to check now. I just hope you are correct as this would be easy to fix.

 

check your connections on your alternator

 

rod it goes directly from the alt to the clocks batt light

 

Will do this in the morning, but its not easy, it got a cooler & Heatshield fitted to its back end & to remove them you have to take the belts off & move several pipes etc. on a standard car it would be easy i know.
Rod

 

Rod, the blue wire goes straight to the alt/no charge lamp in the instrument cluster.. you could wire it straight to a bulb by the side of the alternator to get it working quickly if needed.

 

martin can he not bodge the blue wire to a live feed wire of some discription ?

 

TBH ... Most modern alternators are self-exciting, through the electronics arrangement in the alternator itself.
By the sounds of it, it's most likely a failed voltage regulator in the alternator.
Are you getting nothing above battery voltage Rod, when you test the output?
You do need to check the connection integrity in the connectors tho!

 

Ginge, Martin just told Rod how to get it working temporarily!!!

 

Thanks mate thats what i needed to know . Will check bulb & the wire for continuity & replace if its broken. Its deffo something ive done today as it was OK before. Its just a pain as its not a 10min job .

 

yep, connect the blue wire to a bulb (5 watt should do) and the other side to a live... that will sort it

 

Yep that sounds like the first step will try that first then i will know, thanks Martin.

 

ysorry daz, i never understood what he ment

i somehow ( feel like a right tit now ) thought he ment run another wire to the dash to test it

thats why i should have me keyboard removed

sorry again

 

How the baterry warning light works....

When the ignition is switched on, live power travels through the printed circuit on the back of the clocks and through the bulb. From the bulb it exits down the blue wire from the clocks down to the alternator and pics up an earth though the alternator. When the engine is started and the alternator has been excited, the voltage increases and blocks the path to earth that the blue wires has/had. The alternator needs this signal from the bulb to excite the charge circuits.

If the bulb or wiring is broken then it won't charge.

Most common failure is on the push on terminal at the bacl of the alternator. Wire breaks and corroded inside the terminal.

Second is a broken wire in that area (near alternator).

Third is a blown buld.

Fourth is broken wire else where along the blue wire.

 

Smack on Daz .. .Hope the wire is the problem .. and not internal!

 

Rod has already mentioned that he was working in this area of the car before he had this problem so i reckon that a failed voltage reg would be very doubtful... but not impossible! The original blue wire has prob broken when it was disturbed due to being brittle as a result of the heat it has suffered.

 

I have had ever so slight amount of experience with charging faults on Fords!

 

Yeah, mate .. I had too .. going right back to my old man's E-Type 15AC control box ... and my Viva HA days!

Trouble is .. we never shielded the charge warning wiring properly on the older cars .. but do now on Focus/C-Max and 2006 Galaxy
Stick it too near a turbo manifold .. and as Martin says, it gets knackered quickly.

 

Aren't the wiring looms made by Delphi these days? Not very well compared to some either!! Transit rear door central locking looms spring to mind, and glow plug wiring, starter and alternator wiring on the front wheel drive sheds (and the starters that fill with water as they are right at the front with no sheilding).

 

Think Martin will probably be right , i hope so because that will be easy, off to bed now will report back tomorrow hopefully with positive results.
Thanks Rod

 

Hope its an easy fix for you Rod.

 

for anyone who wants to understand the full function of that innocent looking warning lamp and blue wire - ...

http://www.alternatorparts.com/under...lternators.htm

 

Hi Lads

Problem fixed, got under car & noticed blue wire had been stretched where it leaves the main loom the inner core was broken. Now have 14+v & feeling happy. Going for a shakedown 100 mile drive to check how she goes.
Thanks Rod

 

 

What did you do Rod .. hang a caliper off it? Glad you sorted it!

Al.

 

For anyone else having similar problems, we had a car on teh trip to germany exhibit almost identical symptoms and it traspired the 2 screws securing the brush pack/reg assembly had vibrated loose on the ring. A 2 min fix....












Had we not already removed the alternator to discover this fact!