Battery or alternator?

[dave c59]

Eart strap cleaned but no diference.
New voltage regulator fitted, 14.4v at the battery when charging, however I now have a battery light on permanently! Apparently the voltage regulator was the wrong one, on this model of alternator/ facelift car it is controlled by the CEM - old regulator refitted, battery light off but back to 13.6v.
So do I try the correct voltage regulator or is the charging voltage likely to be the same?

[IainG]

Hi
Do you have access to a DICE/VIDA. ?

There is a section( there is for my V50) that tests the alternator output with the the different inputs from the car.
Might be worth checking first.

Iain

[dave c59]

Of course, I have VIDA, why the hell didn't I think of that!
Can't believe I forgot it, do you know what section it's in?

[oragex]

These are the two replacement regulators available. They usually cover from 01-04 and from 05-09 (07 for V70). Your 05 may fall just in the middle of this, but I would guess it needs the 05-09 one

https://www.fcpeuro.com/products/vol...697015#fitment

https://www.fcpeuro.com/products/vol...637851#fitment

My bet is the right regulator is the one that gives you 13.6v and no light, but something may be wrong with the battery, it may no longer accept a charge - reason why the regulator puts out only the voltage for the car's systems and doesn't try to charge the battery. How do you measure the battery? I disconnect the - cable and measure at the posts

[IainG]

Hi

Originally Posted by dave c59

Of course, I have VIDA, why the hell didn't I think of that!
Can't believe I forgot it, do you know what section it's in?

Sorry can't remember, was a while ago but wasn't hard to find.
It did tests at various input temperatures and had a table of correct readings to compare.

Iain

[electrocoolman]

With regards to the Earth strap connection. Some time ago whilst troubleshooting poor starting problem, the crimped lug at chassis end had some internal corrosion - blue/green verdigris. Not sure if it was under a heatshrink sleeve but I cut off the old lug and crimped a new one on. I also made up and fitted a new cable in parallel. Before you go to these extremes try connecting one of your jump leads between engine and chassis to see if there is any improvement. If your battery is in the boot (as mine is - V70) then don’t forget to check and clean the other connections there. You can also get a conductive grease. RS components do one in a small syringe.

[dave c59]

Originally Posted by oragex

These are the two replacement regulators available. They usually cover from 01-04 and from 05-09 (07 for V70). Your 05 may fall just in the middle of this, but I would guess it needs the 05-09 one

https://www.fcpeuro.com/products/vol...697015#fitment

https://www.fcpeuro.com/products/vol...637851#fitment

My bet is the right regulator is the one that gives you 13.6v and no light, but something may be wrong with the battery, it may no longer accept a charge - reason why the regulator puts out only the voltage for the car's systems and doesn't try to charge the battery. How do you measure the battery? I disconnect the - cable and measure at the posts

Thanks Oragex, new (correct ) regulator fitted and no battery light, charging up to 14.4v. Fingers crossed!

Had the battery load tested, it's hardly holding a charge so new battery on its way, hopefullythis shoould sort this latest problem out for good.