Alternator help

[welshboyo]

Hi guys I been having problems with my charging I am only getting 11.5 when car running . The alternator got rebuilt September last year , I had a mechanic say to me it needs a new alternator but I disagree lol 😂. I could be totally wrong that's why asking advice .
Okay I am not getting the battery light on the dash at all I have checked the leads all are good and all of the fuses . I went under the car and pulled the 3 pin connector off and measured each pin with multimeter and was only getting a reading from 1 pin ??? The other 2 are not reading anything so I am thinking this is a wiring fault any help would be great guys . I forgot to say I have a rev 2 turbo .

[Juliuswws]

Hi,

Have you checked the wires from the alt connector to the fusebox?
I have a rev3 but I'm pretty sure you got it similar.

Alt connector
Pin1: Yellow - goes to the long connector in the engine bay fuse box
Pin2: Black+Yellow - goes to the short connector in the engine bay fuse box
Pin3: White+Red - goes to the long connector in the engine bay fuse box

You should measure 0.1 - 0.2 Ohms (dependent on DMM leads) when measuring the two ends of the wires.

Since you checked the fuses, I'd say the engine bay wires (and factory crimped joints in the loom) are the most vulnerable.

Hope it helps

[jimi]

As above sounds like a wiring fault, alternator wiring is a bit of a weak points on MK2's, I've repaired several.
There's a guide to testing here https://www.mr2oc.co.uk/know-your2/92-m ... blems.html
and a good thread (with pictures) showing fault finding and repair on a MK2 with similar issues here https://www.mr2oc.co.uk/forum/41/167671.html

[welshboyo]

thanks very much for your help guys this has been driving me mad, i took the car to a mechanic and said i needed a new alternator, but i think its what you guys said so going to check the wiring now. am i supposed to get the battery light on the dash when switching ignition on ???
as i have had no battery lights on the dash at all.

[Juliuswws]

Yep, you should have the batt light ON with IGN ON.
Unless the bulb is gone, wires damaged to alternator.
It could be you alternator bad, but check the bulb, all relevant connectors for corrosion, Fuses: ECU-IG, AM2, ALT Sens.
Most importantly, check the wiring as in post #2

Cheers