Whats Wrong With My Electrics?

[ashlee205gti 1]

Went to start the car the other day it was dead!

 

So i charged the battery over night but when i reconnected it it made a humming noise and discharged itself almost immediately, there was nothing when i turned the key in the ignition either.

 

Any pointers on what to check first?

[pugbliss 0]

myself ...i would check all the earths first, make sure they areall clean and tight then i would look for a short somewhere as if its discharging straight away it must be going somewhere, so a short is where my money is, although im not a guru on this type of thing.

[DrSarty 90 1 Cars]

Gut reaction (with no in depth knowledge of your circumstances) = killed battery. Dunno if yours is old/new or perhaps has been cooked by an over enthusiastic alternator, but your battery might not have accepted the charge you gave it at all; so in fact didn't discharge at all. If a plate/cell's damaged in the battery, or painfully low on electrolyte it can go to the grave very quickly.

 

Likewise, if it did accept the charge, something needs to be 'on' to draw current to drain it and a bad earth wouldn't do this. Good earths are vital but your problem, particularly with a 'humming' sounds most odd. That sounds to me like perhaps your solenoid is stuck 'on'/activated and it's that's humming; although it is not engaging the starter motor.

 

A simple test is a swap with a known, healthy battery. That's where I would start. Whilst yours is out, you've got clear access to check/renew the earths (even add one to the shell from the gearbox engine earth) and if it starts fine then you know it was one of two things. Put your old battery back on and, my bet, it won't start.

 

 

Dr - Out on a limb - S

Edited April 14, 2007 by DrSarty

[Alastairh 47]

how good are your terminals on the battery?

[lagonda 42]

Humming noise might indicate a short to me ... but then I'd expect something to be burning or at least smelling pretty hot. It could be a short that has killed your perhaps dicky battery. I'd be very careful about connecting a good battery up. Better to charge yours up & try it in someone elses car. Also I'd connect a resistance meter across your battery terminals once your battery is out of the car & see what reading you get, with EVERYTHING switched off. Assuming you haven't got an alarm/immobiliser to confuse things, the only thing in circuit wouild be the clock, so remove the fuse for that. Your reading should be infinity.

If you do get a reading, I'd start out by checking out the starter & solenoid, & the heavy gauge wiring to it.