Technical engine problems

[deggsyuk]

if I leave my car to stand for a couple of days when I try to start it it sounds like the battery is dead but once ive jump start it and start use it every day no problems any ideas

 

[dumbledore]

Weak battery or alternator or car is draining the battery. To check for drainage, disconnect battery then put a amp meter between battery and live wire. With car electrics switched off you should not have a drainage of more then 50mA.

 

[fingers99]

Test the alternator output with a multimeter set to 20v DC across the battery terminals.

1. Engine off
2. Engine running, no electrical load
3. Everything switched on -- headlights, rear screen demister, etc.

Get the battery drop tested (lots of places will do this for free).

If both check out OK, either a big electrical drain with ignition off (aftermarket stereos are often culprits as are boot light switches) or dodgy connection to battery, earths, or starter motor.