Battery drain when running?!

[bighands 0]

Right weird one time, done a search and cant find anything like this!

I can charge the battery and it will be fully charged, and sit there happily for a week or two, even more i imagine without going flat, but when the cars running it just flattens the battery within half a hour, it still runs but cut the engine and try and start it, nothing!

What can cause the batter to drain, when the engines running??

Altenator is kicking out around 13.8-13.9 volts fully loaded, and have no drain when ignition is off?

 

Mmmmmm strange eh?

 

Andy

[kongo127 0]

Let me check if i understood...

 

You are charging the battery with a battery charger, and then you place it in the car and it´s OK while the car is stopped.

 

But when you drive it, the battery discharges?

[bighands 0]

yea spot on, but i dont take the battery out of the car but leave it in there!

And altonator kicks out just under 14V with rear de mister and headlights ect on!

 

Andy

[kongo127 0]

Well, in this case, it´s obvious that you alternator isn´t able to supply enough power to charge the battery.

 

Have you checked that thin blue wire that connects there?

 

How´s the voltage regulator?

 

In other circunstances i could say that you may have a fried diode inside the alternator, but this should drain you battery all the time.

 

I would carefully check the blue wire and its connections...

[bighands 0]

ah sounds like a plan, but thought just under 14v was enough juice to run at?

Would a simple continuity test on the blue wire be enough?

Voltage regualtor was off a 5 month old altenator as i have had 'issues' with electrics before so should be good!

 

Cheers!

[peteTDI 0]

is the battery/charging lamp working on the dash?

[Goldie 2]

Would a simple continuity test on the blue wire be enough?

 

Id start with continuity test of that cable and check the connections look ok. All being well the resistance should be very low.

[bighands 0]

yea it seems to be charging and the light goes out once the engines started, as i said its got just under 14v fully loaded over the terminals, tho it doesnt seem to go up a lot or break the 14v mark when its not loaded?

Maybe it is the altenator but seems odd that its throwing out what it should?

No way there could be a massive short or load drain when its runnning??!

Og and cables all seem ok, old yea but continunity on them all!

 

Andy

[saysomestuff 0]

doesn't help you but I've had a very similar problem with mine mate.

 

It will start no worries on a fresh battery and can go for a couple of weeks and still start, but once left running for 15 20 mins, the battery's dead. I've changed the starter and it still does the same, I reckon there's a short somewhere whilst running.

[bighands 0]

Ah well at least im not alone on this one, just doing my head in that i cant fault find it!! weird that it seems to have the voltage there but it cant keep up with something!! Wondering what can drain it so quick!

 

Andy

[DanVW 0]

do any of your relays get hot while driving? I mean proper hot not just a little warm :-) could be worth checking as it sounds like something is switching to earth with the ignition on, does it still go flat with the ignition on but without the engine running?

[bighands 0]

Good plan, i will have to check that out!

Could also do a amp drain check with the ignition on, what sort of reading SHOULD i get do you think?

 

Andy

[bighands 0]

Right numbers time!!

Just done every test i could think of . . results as follows` . .

 

Volts:-

12.04 Ignition on

14.04 Running, no load

13.55 Fully loaded, rear de mister, fans and main beams! went up to 13.60 after few seconds

 

Amps:-

0.17 Ignition off

11.50 Ignition on, no immob

12.15 Ignition on, immob activated

 

Think thats everything?

 

The volts dont fluctuate when the revs are increased and there are no hot or even warm relays!

 

EDIT Also just noticed its a 90amp altenator!?

 

Running out of ideas! Everything seems to be ok doesnt it? I dont want to get another altenator when it doesnt seem to be the problem?

 

Andy

[DanVW 0]

Those ignition on current readings don't look right to me... but then again I don't know what they should be :oops:

where did you take those measurements? I really hope you didn't switch your meter to Amps and put your probes across the battery!? :onfire:

 

Not sure how much you know about car electrics here and I don't mean to offend but if your not sure you should get a pro mobile car electrics dude out!

 

As to measure current draw you need to have the meter in series with the battery, ok if the engine is off but your looking at 100's of Amps when you crank the engine, more than enough to fry most home multimeter's! Like I said don't mean to lecture but don't want to see anyone hurt either!

 

Can anyone confirm what the running current draw should be? (with all electrics off! fan, de-mister, lights etc)

[bighands 0]

Ah its ok i no roughly what im doing :-)

Took the amp readings with the meter in series with the neg batt lead, learnt all about blowing fuses when i was trying to find the high drain when the ignition was off after fitting the new engine!!

0.17 amps is actually really good for a corrado, some people seem to have 0.25+ thats 250mah, and mines drawing 170mha :-)

It was 500 before i sorted some seriously botched wiring on the stero!

I would like them to be less, but it will still take about 3 or so weeks to kill a battery with tha drain i think!

I cant get a amp reading with the car actually running, as you said beacuse starting it up with it in series would melt my multimeter!!

But these results are spot on, im confident of that :-)

 

Andy

[DanVW 0]

Hey Andy,

 

Agreed that the ignition off readings are good :-) but not sure it should be drawing 11.5 amps with ignition on but without the engine running :?: I would have though it would be less than half that once the fuel and abs pumps get upto pressure?

 

but like I say I have never measured it so hopefully someone in the know will pop up and confirm? If that is a correct reading then the problem has to be once the engine is cranked or running, which would rule the out window regulators, ECU and ABS pump (as they are powered before the engine cranks)

 

getting confused now :roll:

 

Hope I am helping and not just making things even more confusing!

[bighands 0]

Ah yea i no a bit, but not a lot, and wasnt too sure if 11 amps was a lot! Also that was taken after the fuel pump had shut down.

Oh and to make it a little easyer, it doesnt have ABS, electric windows ect, its a nice basic 'easy to fix' model Pfffffttt LOL

Not sure where to start really, need an electrical wizard to confirm if the readings look ok, and what could be the cause of my mega drain LOL

 

Cheers, Andy

 

Oh, you think your confused!!

[dr_mat 0]

0.17 amps drain ignition off means ~4 Ah per day, so flat battery in about 16 days, i.e. about normal I think.

 

The volts readings look absolutely fine though..

[bighands 0]

so is that a normal drain for the ignition on?

So its definalty not the altenator with good volts readings, the altenator wouldnt drop on amps and not volts?

[dr_mat 0]

hmm, 11amps drain off the battery with the engine running??

I think you must have a short somewhere, can't see another way for this to happen.

I've not tested the current drain with the ignition on, but if it's really pulling 11 amps from the battery that will be plenty to drain it in a few hours.

[DanVW 0]

Hey Andy,

 

You could try disconecting the coil then switch the ignition two position 2, wait for the fuel pump to stop buzzing then measure the current draw from the battery, just to see if the problem is coil related or not?

 

Another trick would be to try pulling out the relays one by one then checking the current draw till you (hopefully pull one and see the meater reading drop) just make sure the ignition switch is OFF when you pull out or plug in the relays!

 

Will get there in the end mate keep the faith ;-)

[saysomestuff 0]

Hi mate, you had any luck with this yet?

 

with an 11amp draw, that means the alternator should be charging at least at that rate whilst the car is running, surely?

 

is it?

[quicky1980 0]

not alarm problem? how old is the system?

[bighands 0]

Right, found the relay thats pulling the massive drain, its No18?

So what does this relay control to cause the drain, took the outer box off it and it all looks hunky dory inside

It went from 12.something straight down to 0.17 8)

But not a lot of good if i cant trace the fault eh!!

 

Cheers, Andy

 

EDIT, sorry just seen its relay No4, and has 18 written on it??

[bighands 0]

Ah ok so done a little searching, like i should of in the first place and thats the X relay, so would kill the drain anyway!

So i got to pulling fuses, and on No9 the drain was gone :-)

So its the rear heater, thats the de-mister i take it, so is this a switch thats shagged or something more sinister?

Oh and the overall drain with ignition off is now 0.2-0.3 now thats low!!

 

Getting more faith as the day goes on, but would that really be enough to kill the battery even with the engine running? surely the altenator can cope with that!!!?

 

Andy