Alternator question

[siross]

Hi,

I am about to embark on quite a large system for my vetra, its a 1.8 sri.

Is there a bigger/more capable alternator that would fit, say off one of the diesel models? And if so how hard are they to fit?

Thanks

Simon

[FIL 4822]

Don't quote me on this but i'm sure the original is upto the job.
I had a new alternator fitted to my last car (cdti 150) as it'd blown the diode. The RAC guy who towed me to the garage said that the alternator only runs when the ECU tells it to. In other words, if the battery starts to get low on power ,the ECU will start the alternator until the battery is fully recharged.
My guess is if you run a system that takes loads of power, the alternator will just run more often.

[ed taylor]

But will it be able to keep up with the output when say all the electrics are on "ie" heated window blower all the lights and "the music".

[scottyd]

just get highest amps alternator that wil fit try phoning lsuk for advice

[siross]

Has anyone tried fitting a new alternator?

The alternator will power the system but thats not the issue, i dont want any voltage drop! Dimming lights when going loud etc

[rushy]

Think basic one is 100 amp but there is a 120 amp.

[Ste]

If you don't want dimming lights on loads of bass, you are looking at the wrong part - ie alternator. At really high transient loads, the alternator will not be able to put enough in, even if you go for the biggest one that will fit. You need to fit a bigger capacity battery too.

Go for the diesel battery, I would have thought that the constant charging of the alternator would be fine as standard, but it might wear out quicker due to higher duty cycle factor.

ECU controlled rotating electrics is new on me. I changed my brother in laws Astra 52 reg diesel alternator the other night, and there was certainly no control over it by the ECU.

Alternators don't charge the battery when it is full anyway, it's the nature of how they work that does that, not control by the ECU.

I could be wrong, but I can't see how / why VX would add that complexity when it really isn't needed.

[rushy]

I though the alternator ran all the electrics once the car was started so in effect its always working.

[Ste]

There will be times when the electrical load is very low, and the battery is topped up fully. But essentially yes, the ALT powers the cars electrical system all the time and keeps the battery full (aims to anyway)

[siross]

a bigger battery and upgrading the big three are also on the agenda, what's the difference beteen the diesel batt and the one I will have? also im guessin vauxhall don't sell these particularly cheap?