alternator service

[jgjones095]

anyone got a guide for servicing an alternator on a v70xc2.4t petrol car?

also what parts are available and where

i'm sure i'm still on the OE alt and i'm getting dashboard lights dim slightly then get brighter on startup when idling

ta

[Georgeandkira]

Year (etc.), please!

Go here: https://www.matthewsvolvosite.com/re...n-the-car.html

A quality rebuilt unit is the way to go given the age of your vehicle.
Sourcing bearings, a freewheel, brushes, a regulator and incidentals makes "tooling up" difficult.
Gotta be a rebuilder around Cardiff or Swansea.

[oragex]

Which year the car? I believe the regulator is different from 2005 on

As for the dim lights, I would purchase a multimeter that can read 10 Amps.

Besides corrosion on the power cables or even cracked power (red) cables at the battery or alternator or engine bay fuse panel, it can be three things:

1. worn out battery (normal after 10 years or so)
2. parasitic drain causing the battery to discharge overnight and getting recharged while driving the car: after a few months of discharging-recharging even a new battery gets damaged and cannot be properly recharged again
3. worn out brushes at the regulator, faulty regulator, or even alternator pulley (or other pulley on the serpentine belt) about to seize


Try first replacing the battery but keep the old one as well. With the new battery and the engine running, read the voltage at the battery: it should read around 14.4V. If it's rather 14.0V or less, the alternator may not be charging properly. If the alternator works fine, the next morning before firing the engine, read the voltage at the battery: it should show around 12.6-12.7V. If it's rather 12.0-12.1V it means there is a parasitic drain (a short in one of the car modules or switches). Better to drive with the old battery until fixing the parasitic drain.

This site has some information on these voltages https://www.batterystuff.com/kb/arti...ry-basics.html

[jgjones095]

ah good point... it's in my sig an X reg '00' v70xc

i've pulled the siren fuse long ago

battery was new about 2 years ago... i know it doesn't mean much if there is a drain on it.
alt belt pulley changed back in jan due to it making a noise after the hg change.
alt belt changed a year or 2 ago

i believe the alt is original which is why i'm starting there...

battery is 12.55v with the car off.
13.6 with the engine running at idle.

checked both with a multimeter and dice.

i should add the dash lights flickering is when the idle drops below 600rpm.... i have a rough / hunting idle sometimes when i 1st start the car... again another issue im chasing!
i just changed the pcv system so the etm is nice and clean.

[oragex]

If the battery was recent and sits at 12.5V 10-15 min. after shutting the engine off, and the alternator only pumps out 13.6V, it would point to the alternator regulator (worth checking it's clutch pulley as well while there).

Is the alternator the original one? Asking because from 2005 the 160A regulator is an entirely different type and when installed into a 2001-2004 it will do exactly that: only charging to 13.5V (in other words, works but not correctly). Yours being a 00 I'm not sure how all this would apply.

You can just replace the regulator with the alternator pulled from it's bolts but still inside the engine. Much easier than to pull it entirely from the engine bay on these turbo engines.

With a new correct regulator, worth surveying the battery, see if it's still good and charges to about 12.6V-12.7V but even at 12.5V it's perhaps not worth replacing it as of now.

https://www.youtube.com/watch?v=Kg-lsya-LiY

[jgjones095]

thanks i am pretty sure it's the original

i just had the engine bay apart lol



am hoping it's just the regulator!

[cheshired5]

Worn brushes will be very obvious so just take the regulator off and inspect it.
This was mine before I changed it for another genuine Bosch regulator.