Charge Light Remains On But Battery Is Charging

[bruce]

Had a flat battery. Ignition lights (oil/charge) would work. Thought it was a faulty wiring at first, since there was a immobilizer fitted (but not operational) with a few loose wires. Wiggled some wires, but didn't change anything. Then the ignition lights didn't come on.

 

RACT guy came to give a jump start. Car runs, but the charge light remains on, and fuel and temp gauges don't work. Ignition lights don't come on with the first click of the key. Checked the voltage on the battery, and it's around 13-14 V.

 

RACT guy couldn't work it out.

The charge light does go out when the gear is put in reverse

Any ideas?

[ke70dave]

sounds like your have a dodgy earth somewhere.

 

thats about the only thing that can explain whats going on there, especially the reverse gear thing.

[LowVp]

regulator, its over charging but also staying connected and discharging your battery when the key if off, with the engine running turn on all of your accessories like lights, stereo, hazards and the light will go out and should indicate that its the regulator that cactus and overcharging

[kryton brown]

It sounds like you've lost the ignition supply to your dash.

Check your fuses, usually the one labled 'meter' goes to your dash.

Otherwise when you were wigglin' wires, you disloged one from the dash.

[bruce]

regulator, its over charging but also staying connected and discharging your battery when the key if off, with the engine running turn on all of your accessories like lights, stereo, hazards and the light will go out and should indicate that its the regulator that cactus and overcharging

 

Tried running the engine with lights, radio, fan, demister and hazard lights, but the charge light still remains on.

Edited May 25, 2010 by bruce

[bruce]

It sounds like you've lost the ignition supply to your dash.

Check your fuses, usually the one labled 'meter' goes to your dash.

Otherwise when you were wigglin' wires, you disloged one from the dash.

 

Checked the fuses with a multimeter and they are all OK. Took the gauge cluster out to check the back plugs and they are well connected.

[Dropz]

check the wires at the alternator are all contacting properly. maybe give them a clean up.

 

if you have a mate with same engine, maybe try swapping alternators or regulators (if you know how to dismantle the alternator) and see if it persists.

[bruce]

I decided to check the fuses again, as the reverse light switch, demister switch and fuel/temp gauges seem to be affected; they are connected to the same fuse.

 

The fuses seemed to be working when tested with the multimeter. I tried to by pass one of the fuses and the ignition lights came on. I put in a new fuse but it only worked if I slid it around in the fuse slot, so it was actually the contact. I got some sand paper to make the contact better.

 

Waiting for the battery to charge up to try it out.

 

Just wondering what could of caused the battery to go flat in the first place? I have noticed that when I used the rear demister the charge light comes on faintly (not real bright). I usually only use it for 5 minutes, but the last time I drove the car I used it for 20 minutes. I wonder if using the demister would be enough to drain the battery? Perhaps the alternator is starting to wear out. I've got a spare I might try.

Edited May 25, 2010 by bruce

[LowVp]

Tried running the engine with lights, radio, fan, dismister and hazard lights, but the charge light still remains on.

 

try and put more load on the alternator

[bruce]

With the fuse contact sorted and a charged battery, the engine runs with no charge light on. The fuel/temp gauges work.

When the engine is running it's 14.05 V across the battery. When head lights and demister are on the battery goes down to around 13.7 V. Just need to see if the battery holds charge.

[ke70dave]

hmmm this is interesting.

 

i would be getting your alternator and regulator checked out by an auto elecy. you can just drop them off and they will bench test it with their load machine.

 

maybe its on the verge of dying which is causing the intermitent..ness.

 

in my experience once the engine is running, almost nothing will cause the alternator light to turn on unless the alternetor isnt working properly (or if you almost stall it, then the light flickers a bit)

 

the alternators are rated at like 35-40A. your headlights are only about ~8A each or so. demister around there. you will be hard pressed to use up 35-40A with the standard equipement in an old corolla. in fact you shoudlnt be able to flatten the battery when engine is running (other wise the electric devision in toyota needs to be fired!)

 

so if your charge light is coming on at all when engine is running (which you describe above) then id say your alternator cannot keep up, and thus needs some attention.

[ninja-philbo]

just went threw this drama changed my altinator no change, changed my main relay everythings sorted. now tryin to work out why the relay went. man i hate electrics