Thread: Electrical problem in a CH Lancer

How old is battery they don't last forever.
Check all interior lights radio etc are off
Check leads on battery are tight, levels etc
Alternator may not be charging

How can I tell if my battery is low and needs to... — Yahoo! Autos

It's none of those causes

Have you got a new sound system fitted with an amp some of these suck the life out of even a new battery.

Might need to have a lecy check it FC
Answer 1


Have you checked the Alternator?

Answer 2


Like most batterys in cars, trucks, ect, they tend to get dirty. A slow battery drain is more than likely caused by a high resistance ["mini"] short between your positive and negative [+/-] terminal posts.
To check this, attach one lead of a low volt meter to the positive [+] post of the battery, and then draw the other lead across the top of the battery. If the meter shows any voltage at all, that's the problem, as it indicates current flow. Wash the battery with a mixture of baking powder & water, and rinse. Be sure the cell covers or plugs are in tight, or if the baking soda solution gets into the battry cells, it will ruin the acid electrolyte. Dry the area between the posts & check with the meter again.


Answer 3

While answers 1 and 2 are not wrong, there could be a similar high resistance fault [or mini short] to ground anywhere in the wiring system WHICH IS "HOT" ALL THE TIME [even when the ignition switch is OFF]. One example of this would be where a wire was pinched between two grounded metal body components, or pulled tightly around a sharpe edge of a sheet metal component, with a resultant pinching, chaffing, or cutting of the wire insulation allowing only minimal minimal contact to the grounded component. That would allow a small flow of current which, when the alternator is not generating electricity, would create a small, but continuous drain on the battery. Also, there could be many other possible which I cannot recall at the moment. j3h

Read more: http://wiki.answers.com

I've had a diode pack go in the alternator - there was enough of a short to cause the battery to drain overnight, but the alternator could still charge the battery. The easy test is to charge the battery, confirm that it is charged, disconnect the alternator and check the battery in the morning. If it's still good, then start giving nasty stares to the alternator.

If it's not the alternator, pop the positive lead off the battery and put a multimeter with a decent ammeter between the terminal and the lead - if the car is drawing anything more than 50-100 milliamps with nothing turned on, then you get to start isolating systems at the fuse box to narrow down what part of the circuit is doing it.

The battery only drains with the key in the ignition. Keyless, nothing happens

What would cause the idling problem?

Rough idle - in no particular order - dirty/malfunctioning MAP sensor, low pressure in fuel line, vacuum leaks in hoses, dirty fuel injectors, weird electrical problem with the ECU....

My suspect would be either the MAP or throttle body as a first place to try, followed by checking vacuum lines or other linkages.

After that you'll need the manual as this will give you the details needed for fault finding...however with the price of some manuals these days, it can be just as cheap to go to a dealer and have them plug in the machine that reads the on-board diagnostics codes.

It can't be too serious (yet) as the ECU hasn't thrown up a fault code.

And if the battery is only draining with the key in, you now just have to start working through which particular circuit has the high current consumption on it....