Alternator or Battery problem in EL XR8. Help haha.

Today my XR wouldn't start, since i got it a few weeks ago, it's always seemed a little hard on the start up. Today it wouldn't even turn over, to the point where it would just click when I turned the key.

I bought a new battery and chucked it in, and started up fine, but i've disconnected the power as I don't want it draining if the alternator is stuffed.

Is there anyway to find out whether it is my battery or the alternator without going to a mechanic? The battery light isn't staying on when I turn the car on, so i'm not too sure.

Help pleeeeease haha.

[ebxr8240]

High idle and disconnect battery...If it stops ..Alternator is NOT charging...The best way is to use mutimeter..On early V8 alternators ..If a cell was dead in battery it would over charge...Check that boot light is turning off???

So...start the car, and rev the engine out, then just pull the cable off the battery?

Is that even safe?

[eav8]

do not rev it out. if you remove the earth lead whilst the car is running it should keep running if the alternator is good. If it dies the alternator is likely faulty......Preferably use a multimeter set to 20v DC and place the black lead on the negative terminal of the battery and the red cable to the positive of the battery (while the car is running)and you should get a reading around 14v....If reading is 12v or less then alternator is likely faulty. This will not damage anything.

[ilsautomotive]

The multimeter method is good.

As for the battery, a simple charger like my 1600 mA Projetca is well worth having. It won't overcharge the battery and prevents the flattening that happens even when it's disconnected. With regular charging, an Exide battery I bought some years ago is still going fine.

[NZ]

The alternator on youe EL uses the same internals as a 6cyl. If your competent enough you can get a known good 6cyl unit and swap the insides into your V8 alternator housing.

[gthofan]

when an alternator dies, its usually just the voltage regulator. easy change over, just the black box type of thing on the back of the alternator. but some heavy duty and some bosche alternators have the voltage regulators inside the guts, not exposed, and these are un serviceable.

[NEG]

you should be able to tell if the alternator is dead by looking at the volts guage on the dash.

Ok, left the battery on over night and it started fine this morning.

Bought a multimeter, and used it on the battery with no stereo but air going and it was 13.70ish, with stereo on it was 13.55ish, and with stereo loud it went to abou 13.40.

I also bought new terminals, cause I think mine were slightly dodgy, but are those readings fine? Meaning the alternator is fine?

[LUXO_8]

Originally Posted by gthofan

when an alternator dies, its usually just the voltage regulator. easy change over, just the black box type of thing on the back of the alternator. but some heavy duty and some bosche alternators have the voltage regulators inside the guts, not exposed, and these are un serviceable.

except on the V8 altinators (and i think EF/EL6cyl alternators - unsure) the reg isnt serviceable

[efgiar]

u could wreck the car, and sell me the front conversion stuff ;) haha jk

[Brent79]

hey slippy... i had a similar problem on my EB. Alternator was charging but if i left the car over night, it would discharge the battery. Reason for this was a stuffed diode in the rectifier. The battery charge was leaking back thu the alternator coil. Try dissconecting the black/white wire from your battery terminal, reconnect it and if u see a spark jump then its a good indication the diode is stuffed.

Brent