Strange Charging Problem On Bx16v Engine

[macaroni 17 1 Cars]

A while ago my car started mis-behaving. From cold, the battery seemed really low on charge; sluggish starting dim lights etc, then suddenly after a few mile sof driving it would perk up, everything would brighten, heater fan speeds up, etc.

 

My local garage diagnosed a flat battery and replaced it. I wasn't convinced but the problem went away for a while.

 

It is now coming back, to a lesser extent, but I feel it will get worse. Given its a new battery I can only blame the charging system.

 

The light isn't on when running and again, after a few miles, everything is fine until next morning when everything electrical seems sluggish.

 

Anyone experienced anything similar and got a solution?

 

I'll check the charging voltage when cold tomorrow, but any help gratefully received.

 

Cheers,

 

Antony

[Henry Yorke 269 3 Cars]

Sounds like a bad earth

[steve@cornwall 100]

Sounds like a bad earth

 

possibly also an undersized battery? especially if the garage swapped like for like

[Sloppy 0]

Sounds like a bad earth

 

agreed, check and clean/lubricate the earths to and from the engine

[macaroni 17 1 Cars]

Thanks for the replies, I found the one from the gearbox to the plate with the ignition module on and cleaned that.

 

Any more to look for?

[welshpug 1,680]

sounds more like a voltage regulator issue to me

[Anthony 1,003]

Yup, I agree - I'd be looking at the alternator if the battery is definitely OK.

 

What is the voltage shown by the battery with the engine off

What does it increase to when the engine is initially started?

Does the voltage then increase after revving the engine to 4000rpm or so?

Does the battery/charge light come on with the ignition before the engine is started and go out when the engine starts?

[macaroni 17 1 Cars]

Just to update this; I cleaned and oiled the earth straps going to the ignition module plate and although they didn't seem very dirty, the problem has gone away.

 

If it re-appears, I'll focus on the alternator.

 

Thanks for all your help and advice.

 

Cheers,

 

Macaroni