Cars started eatin batterys

[Rossco 0]

My car has started munchin its way through batterys, i thought it was just a guff battery so i replaced it with a bosch silver top mother, by this morning it wouldnt even turn, plenty clicks from the starter tho, the thing is when i check to see how much voltage is in the battery it says 14 odd volts, odd?? If i put the battery on charge for an hour everything is mint for a couple of days

 

Any suggestions??

 

There is no boot light before anyone suggests that one :D

 

Cheers

[Walesy 0]

I assume your alternator is ok mate?

[bix 0]

Sounds like the starter is fecked, do the lights go dim when the starter clicks?

[Rossco 0]

The altenator is about 8 months old, i dont think the lights go dim, any of you guys know how i can test the drain on the battery with a multimeter, ill just go hauling out fuses till im on a winner

[bcstudent 0]

Get a mate to turn the key while you belt the starter motor with something solid. I'd say the starter motor is the problem as the battery is charged and the solenoid is apparently engaging.

[Andy D 0]

 

 

If you want to carry out a drain test this is how you do it.

 

First fully charge battery

 

Remove negitive lead

 

Take your muiti meter and connect one lead to the neg post on bat and one to neg lead.

Then set up your multimeter to amp on the 10amp fused circuit (see pic)

 

On the meter you should get a reading of how many amp are being drawn though

 

The max you should see 0.05a(50Ma) anymore and you have a drain.

 

Make sure that all the doors are closed all interior light are out and keys are out of the igniton or you will get a false reading. Also make sure you internal 10 fuse is ok on your meter.

 

If you are carrying this out on a modern day car you have to wait for about half an hour so all the ecu go to sleep. As corrado's don't use muiltiplexing you need not worry.

 

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[Rossco 0]

Cheers for that man thats ace, i charged up another battery and lobbed it in, when i fired up the car the voltage accross was 12.6v, should be 14v right?? The thing is the alternators only 8 months old, anything else that could be causing the lack of charge?? Can the battery drain through the alternator??

 

Cheers guys

[bcstudent 0]

Was that measured at idle?

[old man 0]

have you looked at your voltage regulator.Had same type of problem even took bosch silver back to shop same thing happened a month later with new one.Checked regulator and the brushes were goosed.No problems since.

[Rossco 0]

The brushes were new with the alternator but ill investigate, Student - yeh that was measured at idle

[andy 0]

Cheers for that man thats ace, i charged up another battery and lobbed it in, when i fired up the car the voltage accross was 12.6v, should be 14v right?? The thing is the alternators only 8 months old, anything else that could be causing the lack of charge?? Can the battery drain through the alternator??

Cheers guys

If you're only measuring that voltage (12.6V) with the car running then something is wrong with your charging circuit, either your alternator is goosed or perhaps the cable running from the alternator to the battery is damaged/misplaced? You should see 14V ish as you say. Your battery will not charge properly at 12.6V hence your battery munching.

[Supercharged 2]

The alternator belt is tensioned correctly I take it?

[Rossco 0]

Its a G60 mate, self tensioning eh, ill investigate the cable running from the alternator to the battery, its the only thing in the setup that isnt well new

[bcstudent 0]

It's unfair to suggest that an alternator should produce 14v at idle and is faulty if not. My 16v will discharge its battery if left unused for more than four days and I've read about other early Corrados that do something similar.

 

Have you been using the car less recently?

[Andy D 0]

Ok first thing turn the ignition on does the battery light come on. If no then you first need to test this circuit cos if this circuit is faulty the alternator will not be excited and won't charge.

 

Remove the thin wire off the back of the alternator get someone to hold this wire to the body of the engine this will earth out the circuit. Then switch on the ignition and see if the battery light comes on. If it does then this circuit is fine. If it doesn't then there is a fault i.e. bulb blown circuit board on instruments is faulty or there is a broken wire some where. If there is a fault then you can manually turn the alternator on by touch the small exciter output on the altenator to the positive from the batt you will hear an engine tone change as the alternator starts charging. Once the alternator is charging the wire can be removed.

 

Right if the light comes on then you can continue with the checks. Start the car probe the battery terminals take a reading. Next probe the output wire on the alternator take a reading. Keeping the probe on the out put touch the neg probe on the positive of the batt. This is called a drop test and give a reading of how many volts are lost from output on the alternator to the battery. The maximum that should be lost is 0.5v. Do the same on the body of the alternator to the earth of the batt.

 

Ok take a look at you readings the battery at idle should be charged at about 13.2 to 14.5volts any high or lower you have a problem. Then switch on the headlight and rear demister the charge rate should not drop below 13v this is called a load test to check the voltage regualtor is compansating for the power usage. Hope this is clear this is the procedure i use at work.

[andy 0]

It's unfair to suggest that an alternator should produce 14v at idle and is faulty if not. My 16v will discharge its battery if left unused for more than four days.

Then there's something wrong with it :-) Its unfair to suggest that's normal :-)

[Andy D 0]

Well that is what a lot of manufactures go by. I will say that I have had a lot of problems with recon alternators which are charge but not that strongly. I personally think the quality of alternator that are recon is no way at good as they used to be so i would recommend to get one which has been done by a good company i try to use Lucus. Hella alternator i have found can vary quite a lot i fitted one to a BMW 316 the other day and the charge rate at idle wasn’t all that strong but when you revved the car the voltage came up again. I have just checked my car at idle no load 14.2v then i loaded it up it dipped to 13.8 my alternator is a genuine vw one.

[Rossco 0]

Thats the thing my alternator is a genuine vw one as well, brand new 8 months ago

[Andy D 0]

Did you test the alternator out put at idle? Try taking the battery voltage with the vehicle not started then take it when its running then take with it reving at 3000rpm if the voltage rises then the alternator is a bit weak. If the voltages are roughly all the same then all you are reading is battery voltage and the alternater is not charging. If this is the case you can get a regulator from partco/brown brothers for about 20 pound could try this and see if it will sorts the problem. Think the part number is ugcucb403van best thing to do is take yours uff and match it up.

[Skimask 0]

My car has started munchin its way through batterys, i thought it was just a guff battery so i replaced it with a bosch silver top mother, by this morning it wouldnt even turn, plenty clicks from the starter tho, the thing is when i check to see how much voltage is in the battery it says 14 odd volts, odd?? If i put the battery on charge for an hour everything is mint for a couple of days

 

Any suggestions??

 

There is no boot light before anyone suggests that one :D

 

Cheers

 

My mate had a car in with the same scenario as yours. In this case all that was required was the battery terminals cleaned up. The old battery was actually quite good - it was the terminals that weren't making a contact properly.

[Rossco 0]

I greased up the battery terminals today and charged it, i bunged it back in the car and put the voltmeter accross it, its now reading 12 volts, ill try changin the brushes/regulator as i have a spare one, it bloody weird like

[Andy D 0]

It does have batt light when the igniton is on doesn't it ?

[Rossco 0]

Yep it sure does, but once the car is running the light goes out, surely if the circuit isnt charging correctly then the light would show on the dash, isnt that the whole point of it being there??

[RW1 0]

ill try changin the brushes/regulator

 

With the battery disconnected or you can easily blow the regulator.

 

Dash light is not always there if an alternator is not charging properly. It goes off when the alternator output voltage is greater than battery voltage. ie. Alternator 12.01 to 14 volts is greater than battery 12.00 volts for example.

 

12 volts does not sound right if the battery is charged (yes , agree if the battery is flattish it will not be 14 volts immediately). The alternator will be/should be 14 volts-ish at idle as well as at running speeds providing the electrical loads (lights, fans, etc.) are off.

 

Either the voltage regulator has blown or the diode pack isn't working.

 

You've not run the engine with the alternator disconnected from the battery at any time???

 

.

[Rossco 0]

Nope never run, ive never disconnected the alternator, just disconected the battery to charge it and put it back in again