Electrical problems, where to start?

I know I'm being a complete pest at the moment but my range rover is driving me mad.

The biggest problem is me as I just don't know where to start with it and I could just do with some help making a start.

I have a worsening problem with the electrical situation on my 99 4.6 Thor, right from day 1 (18 months ago) its not been wonderful in the fact that it would only last 10 days or so without needing a jump to start. It seemed to be getting worse and would last 5-7 days so I took it that the battery was getting weak.

I replaced it with a 130ah battery from battery megastore and it seemed no better, infact it seemed worse because once the battery was flat when jumping the car it needed the EKA code (which it never did with the old battery)

Engine running voltage across terminals 14.4v
Engine of after a long run across terminals 12.7v
"Fully charged" according to charger (ctek MXS 5.0) 12.62v
This morning after 20 hours idle it was down to 9.4v
Negative lead D/C from battery the meter was showing 11.4v

These figures are taken with a fluke multimeter.

What frustrates me is that the charger claims to refill the battery in an hour, which is not possible, yesterday I drove 60 miles and the car wouldn't restart, I jumped it from a spare battery (that sadly wont fit, I tried!) moved the car and it then started quite happily after that so I just dont know what is going on. I actually replaced the alternator the other day to get rid of an intermittent "alternator fault" that's been showing on the dash from time to time but its never had a problem recharging the battery until the last couple of weeks where its been struggling after a jump to start again after a drive.

The battery is under warranty but if I send it back and its the car at fault I will get charged.

Basically I'd like to do a drain test but I dont really know how, if there is anyone local that I could see for advise or a guide somewhere of what to do in what order to try and see what is going on!

quavey said:

I know I'm being a complete pest at the moment but my range rover is driving me mad.

The biggest problem is me as I just don't know where to start with it and I could just do with some help making a start.

I have a worsening problem with the electrical situation on my 99 4.6 Thor, right from day 1 (18 months ago) its not been wonderful in the fact that it would only last 10 days or so without needing a jump to start. It seemed to be getting worse and would last 5-7 days so I took it that the battery was getting weak.

I replaced it with a 130ah battery from battery megastore and it seemed no better, infact it seemed worse because once the battery was flat when jumping the car it needed the EKA code (which it never did with the old battery)

Engine running voltage across terminals 14.4v
Engine of after a long run across terminals 12.7v
"Fully charged" according to charger (ctek MXS 5.0) 12.62v
This morning after 20 hours idle it was down to 9.4v
Negative lead D/C from battery the meter was showing 11.4v

These figures are taken with a fluke multimeter.

What frustrates me is that the charger claims to refill the battery in an hour, which is not possible, yesterday I drove 60 miles and the car wouldn't restart, I jumped it from a spare battery (that sadly wont fit, I tried!) moved the car and it then started quite happily after that so I just dont know what is going on. I actually replaced the alternator the other day to get rid of an intermittent "alternator fault" that's been showing on the dash from time to time but its never had a problem recharging the battery until the last couple of weeks where its been struggling after a jump to start again after a drive.

The battery is under warranty but if I send it back and its the car at fault I will get charged.

Basically I'd like to do a drain test but I dont really know how, if there is anyone local that I could see for advise or a guide somewhere of what to do in what order to try and see what is going on!

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Summat wrong with your Ctec or the battery, it should raise the battery voltage above 14 volts before it goes to float charge mode, I would expect to see the battery showing 12.9 volts to 13.9 volts immediately after the charger is disconnected. 12.62 volts is 50% or below charged.
You can get cheap clamp meters from CPC to measure current drain brand is I think Tekma or Tenma, can never remember.

Datatek said:

Summat wrong with your Ctec or the battery, it should raise the battery voltage above 14 volts before it goes to float charge mode, I would expect to see the battery showing 12.9 volts to 13.9 volts immediately after the charger is disconnected. 12.62 volts is 50% or below charged.
You can get cheap clamp meters from CPC to measure current drain brand is I think Tekma or Tenma, can never remember.

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I should be more clear sorry, the 12.62v is after the charger has been disconnected I will look for a clamp meter to measure the current drain, am I right in thinking this is placed on a terminal of the battery to see what drain there is?

I have just looked at it, its been on charge for an hour and its at stage 5 (which is the analyse stage) and its at 13.05v

Halfrauds does free battery tests


You can measure drain with your fluke, just don't start car with it connected, sure a clamp-on is easier but in lack of better fluke will do

Druim said:

Halfrauds does free battery tests


You can measure drain with your fluke, just don't start car with it connected, sure a clamp-on is easier but in lack of better fluke will do

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I was thinking that I might go to halfords and see what they can do to test it.

Yeah I am aware that I can do it with the fluke, however this tester is probably as old as me as it was Dads and will only take 2 amps I did have a go and feel I may have blown the fuse in it (oops). Ive ordered a clamp meter and it should be here on wednesday.

I've also engaged the recond feature on the charger which throws 15.8v into the battery to shake it up a bit.

As I suspected though the charger claims to have brought the battery from 9.4v and empty to 14.05v in less than 2 hours

quavey said:

I should be more clear sorry, the 12.62v is after the charger has been disconnected I will look for a clamp meter to measure the current drain, am I right in thinking this is placed on a terminal of the battery to see what drain there is?

I have just looked at it, its been on charge for an hour and its at stage 5 (which is the analyse stage) and its at 13.05v

Click to expand...

I would not to expect the battery to drop to 12.62 for some time after the charger has been disconnected.
Clamp meter just goes round the battery cable, negative is usually easier but either will do.

Datatek said:

I would not to expect the battery to drop to 12.62 for some time after the charger has been disconnected.
Clamp meter just goes round the battery cable, negative is usually easier but either will do.

Click to expand...

Could it be dropping due to a failed battery? Or a large battery drain from the car?

A friend of mine has a spare battery that we are going to try later on and see if its any better on the other one.

quavey said:

Could it be dropping due to a failed battery? Or a large battery drain from the car?

A friend of mine has a spare battery that we are going to try later on and see if its any better on the other one.

Click to expand...

Could be the battery or as you say drain from the car. Testing is the only way forward. It's not unusual these days to have a new battery fail even with the big name brands.

Datatek said:

Could be the battery or as you say drain from the car. Testing is the only way forward. It's not unusual these days to have a new battery fail even with the big name brands.

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OK, realising my fears! It must be a hell of a bad drain to empty a 130Ah battery in 20 hours!

Is there a procedure for testing electrical drains anywhere? I've never had to test for them before.

I'm going to assume, unlock, open bonnet, attach clamp tester then lock the car. (it will beep to say the bonnet is open)

Then I'm watching the clamp meter to see the current drain drop of as everything goes back to sleep. How long should it take for the becm to sleep after the car is locked?

Engine running voltage across terminals 14.4v
Engine of after a long run across terminals 12.7v
"Fully charged" according to charger (ctek MXS 5.0) 12.62v
This morning after 20 hours idle it was down to 9.4v
Negative lead D/C from battery the meter was showing 11.4v

These figures are taken with a fluke multimeter.

What frustrates me is that the charger claims to refill the battery in an hour, which is not possible, yesterday I drove 60 miles and the car wouldn't restart, I jumped it from a spare battery (that sadly wont fit, I tried!) moved the car and it then started quite happily after that so I just dont know what is going on. I actually replaced the alternator the other day to get rid of an intermittent "alternator fault" that's been showing on the dash from time to time but its never had a problem recharging the battery until the last couple of weeks where its been struggling after a jump to start again after a drive.

Click to expand...

If you alternator voltage reg was on the fritz its probably damaged the battery..
Had this on our silver P38.. had battery problems, changed battery as it was about 6 years old, new battery after a short while would discharge. Checked the voltages, it was high, in the 15.8 region. changed alternator with the battery never a problem.

The C-Tek's are excellent.. i have 6 of them. however if the battery is damaged, there is nothing they can do.

If your previous dicky alternator has screwed the battery, it's fecked.

shame ur not closer or i coulda got the meter out and done some checking. if your alternator was previously fecked ie over charging it woulda fried the battery. seeing as the old battery was performing better than the new one looks like the newer one is fecked.

Make sure the clamp meter you ordered measures DC amps, most only measure AC amps.
Place the clamp meter around one of the battery cables with the engine off and switch on the lights. Check the reading, it will show either a + or - reading. If it's a + turn the clamp meter round and it should show -. This would be correct as the battery is being drained of power by the lights. Remove the meter turn off the lights and start the engine. Replace the clamp meter the same way as before. You should see a + reading if the car is charging. Switch off the engine and lock the car. It does not matter that the bonnet is open. Watch the meter and after 2 mins the current drain should fall to about 0.05 amps and stay at that.

Hope this helps. Good luck.

ukadamwest said:

If you alternator voltage reg was on the fritz its probably damaged the battery..
Had this on our silver P38.. had battery problems, changed battery as it was about 6 years old, new battery after a short while would discharge. Checked the voltages, it was high, in the 15.8 region. changed alternator with the battery never a problem.

The C-Tek's are excellent.. i have 6 of them. however if the battery is damaged, there is nothing they can do.

If your previous dicky alternator has screwed the battery, it's fecked.

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Heres to hoping that is the case and it will get swapped under warranty!

biketeacherdave said:

shame ur not closer or i coulda got the meter out and done some checking. if your alternator was previously fecked ie over charging it woulda fried the battery. seeing as the old battery was performing better than the new one looks like the newer one is fecked.

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I do appreciate the offer mate but London is a fair pull from me! I'd have to save up to get home! haha.

Don1 said:

Make sure the clamp meter you ordered measures DC amps, most only measure AC amps.
Place the clamp meter around one of the battery cables with the engine off and switch on the lights. Check the reading, it will show either a + or - reading. If it's a + turn the clamp meter round and it should show -. This would be correct as the battery is being drained of power by the lights. Remove the meter turn off the lights and start the engine. Replace the clamp meter the same way as before. You should see a + reading if the car is charging. Switch off the engine and lock the car. It does not matter that the bonnet is open. Watch the meter and after 2 mins the current drain should fall to about 0.05 amps and stay at that.

Hope this helps. Good luck.

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Thank you mate thats brilliant gives me a set of things to do and try. Annoyingly I'm away for work until Wednesday from tomorrow morning so won't get chance but the clamp meter wont be here until then anyway...And thanks for the advice, as you said the one I had ordered was indeed AC only for measuring current, ive ordered another one that does do DC current...

To top everything of I went to my friends house to try the spare battery and it was the wrong type so wouldnt bloody fit! It never rains!

If the new battery doesn't perform as good as the old battery then you either have a bad earth or the new battery is fecked I had an alphina from the battery megastore that lasted 3 months

I had an alphina from the battery megastore that lasted 3 months

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I had a varta silver that lasted 8 weeks on car unused and connected to a c-TEK

Don1 said:

Make sure the clamp meter you ordered measures DC amps, most only measure AC amps.
Place the clamp meter around one of the battery cables with the engine off and switch on the lights. Check the reading, it will show either a + or - reading. If it's a + turn the clamp meter round and it should show -. This would be correct as the battery is being drained of power by the lights. Remove the meter turn off the lights and start the engine. Replace the clamp meter the same way as before. You should see a + reading if the car is charging. Switch off the engine and lock the car. It does not matter that the bonnet is open. Watch the meter and after 2 mins the current drain should fall to about 0.05 amps and stay at that.

Hope this helps. Good luck.

Click to expand...

Orientation of the clamp meter does not matter, DC ones do not necessarily show direction of current flow.
Time for BECM to go to sleep seems variable and it should drop to 0.030A (30ma).

Cheers guys, before I went to work this morning I did put the meter on it to see what the voltage had dropped to overnight and it was 12.27v, far better than 9.4 the previous day. I wonder if the recond setting on the charger has done some good...

I will await the arrival of the clamp meter and post my findings!

Right to start this up again:

After 3 days on charger/recond:

Charger had been of for maybe 10 minutes:
11:45 - 13.06v
16:15 - 12.56v
At this point:
Ignition on 12.03v
Ignition of 12.32v

22:40 - 12.24v

So basically full to empty in 11 hours...

Put her back on charge and I've used it today and its been no problem, but i took it to Halfords and got them to run a battery test and print out on it which has come back as Advise replacement - looking like the battery its rubbish so I will call them on Monday and arrange a replacement

At this point I then found the clamp meter on the back step of the house so no idea when that was delivered.

Anyway I've put the clamp meter on and with the car unlocked its reading about 0.5A and with the car locked and after 15 minutes or so its down to 0.42A (varying a touch) I'm aware this should be nearer 0.03A

I will keep taking some measurements from it over the next few hours and see what happens.

Batteries die very quickly if they are completely discharged.

I'm now really looking to find the battery drain as well as it shouldn't be pulling as much as it is. Are there common culprits to look for? Am I going to damage anything by pulling fuses out and seeing the effect?

Should I have a look at the relays as well?