easy electric q.
55ant - 11/1/10 at 01:59 PM
hi all,
ok got a 4x4 thats driving ok but not starting. even after a 2 hour drive there's no juice in the battery,
im pretty sure the car has been in the water at some point, can this do a lot of damage to an altenator? and can they be repaired if it is this thats
faulty. or is it the battery, probably goin to replace the battery anyway.
cheers, ant
snakebelly - 11/1/10 at 02:13 PM
just check the voltage at the battery with it running, is it somewhere between 13.5 and 14v? if so its charging
ReMan - 11/1/10 at 02:18 PM
quote:
Originally posted by snakebelly
just check the voltage at the battery with it running, is it somewhere between 13.5 and 14v? if so its charging
Beat me!
As above this would indicate either alternator or associated wiring/earths.
Else its most probably the battery
blakep82 - 11/1/10 at 02:20 PM
if it won't start but runs ok, then i'd say the alternator is fine (does the charge light come on?)
my BMW did this. would start sometimes other times i'd have to roll it on a hill, drive fine for ages, stall at traffic lights (i didn't
have it long and wasn't used to the heavy clutch on it) go to start it and the battery had nothing in it at all.
new battery, problem solved
smart51 - 11/1/10 at 02:22 PM
Being in the water won't kill the alternator. Driving in the rain soaks everything under the bonnet and doesn't kill it.
55ant - 11/1/10 at 02:24 PM
hmm, ok ill go dig out the voltmeter jobbie, hopefully just need a battery.
dhutch - 11/1/10 at 02:35 PM
quote:
Originally posted by snakebelly
just check the voltage at the battery with it running, is it somewhere between 13.5 and 14v? if so its charging
I would agree, charge voltage should be around 13.8 ish.
- An secondhand or recon alternator is a simular price to a battery and may not evern be much harder to fit but you do need to isolate which it
is.
Presumably your jump starting it to get it going? If you put the head lights on full beam having got it running are they bright? Very crude but simple
way of testing the battery voltage to given an indication.
Daniel
andyharding - 11/1/10 at 03:17 PM
I'd bet the battery is fooked
speedyxjs - 11/1/10 at 05:29 PM
Pretty sure that will be the battery. Thats exactly what my donor car used to do.
55ant - 11/1/10 at 06:42 PM
ah well thats good news, how about once its stared it will run for 2-3 seconds the n die? still battery?
twinturbo - 11/1/10 at 08:20 PM
Check the earth from the battery/body to the engine engine.
TT
wilkingj - 14/1/10 at 03:16 PM
Check the water level is above the plates in each cell. Top up with De-Ionised or distilled water. (ie not from the kitchen tap!)
Charge up the battery overnight, and take it to a tyre / battery service place and get them to do a load test.
This will tell if the battery is fooked or not. (Its usually a free test).
If the battery is OK, then look at the Alternator.
Usually about 12v without the engine running and about 13.5-14V with the engine running (at say about 2000 rpm, ie not on tickover)
As you say its a 4x4.... (its been subjected to loads of Mud and water mix?)
Before you go and lash out on an alternator, or battery, check ALL the connections at the Alternator, Starter Motor, and the Battery terminals.
If the Battery terminals have the green fur on them, then wash gently with warm water and it will disolve away.
Clean the battery posts, and the connectors. Grease with Petroleum Jelly (Vasseline), only use axle grease as a last resort. We have been using
P-Jelly on battery terminals for 40 years at work (BT). Its the correct stuff.
Check the earth connections at the body, and the earth strap from the chassis to the engine. Make sure the chassis earthing points are clean metal and
not rusty.
Again clean and grease as necessary.
Failing all that, its a new alternator and / or battery.
Basically eliminate what you can for nil cost. Then test the battery.
The check the alternator output.
The replace faulty component.
