Got my retest for my MOT tomorrow last chance before I have to pay again . The problem is my alternator is not charging the battery. I have just swapped alternators over with my mates (thanks Stoo) and I know this is working but still no charge going to the battery. So its down to wiring I know the main feed to the battery is ok but as for the other smaller wire what do these do and is there anyway of checking these...? Please help as it looks like im heading for a late one

Oh its a Mk2 Xr2 with ERST engine and alternator

 

may sound silly, but is the earth ok?

 

maybe your battery is fooked and not taking charge.
check the cells arent dry for a start, then get a volt meter on it, set it to V20 and if it gives between 11.5 and 13V its ok, then test it with the engine on, rev it a bit as the alternator only starts to fully charge after around 3K rpm

 

dunno mate but i had a problem with my battery charge only lasting a few days and then needing a boost.. turned out the battery was gubbed..

can only suggest to give all the connectors a good clean, maybe even check the cables from the alternator to make sure they aren't gubbed either..

the other wires feeding to the altnernator should have about 12volts i think, but i recall one of mine was about 7volts, no sure to be honest..

https://passionford.com/forum/viewto...826&highlight= - might give you some info.

 

Yeah earth is ok. Got the battery checked yesterday and all is well. The only thing I can think of it being is the smaller wire which comes from the alternator, anybody know what this does/goes to as I could run an external wire just to get me through tomorrow if this is the prob

 

also check earths are good.

 

What!!

You told me you were taking it away to polish it

Cant help you with this other than lending you parts,if you need anymore,let me know

 

small blue wire is for the battery light on the dash

 

Think I may have traced the fault, after getting advice from someone on xrtwo.com they have brought to my attention that the battery light on the dash must light up (which mines doesn’t) to complete the circuit to allow charging. One bulb change coming up Hope this works

 

Make sure the red ignition light comes on OK
I had exactly the same problem and it was down to the wire that comes from the altenator to the dash, the alternater needs this wire to be OK before it will charge the battery. Sounds crazy I know, but a smart arse mate of mine saved me a load of aggro after I had swapped engine looms on a 24 valve conversion. It refused to charge the battery or illuminate the ignition light, ran a new wire from the alternator to the dash and it works fine

Mark

EDIT!

Beaten to it!

 

WooHoo!

Hope this is the problem solved for you

But dont worry if it is,something else will come up tommorow to keep you busy

 

 

Bulb was ok, just ran an external wire from the alternator directly to the multiplug on the back of the clocks. Hey presto we now have a working battery light (Hope this completes the circuit). It’s staying on very dimly though but hopefully this will give enough charge for them to complete the emissions test tomorrow and I can sort it out better tomorrow night. Thanks for your help, couldn’t of done it without youz

P.s Everybody except Stoo that is