Possible major electrical problem

geoff11 · 1st March 2009, 19:33

Strange one this, this morning I replaced my passenger mirror with the bullet type and all was well had the ignition on and off a few times switched everything off and had lunch. this afternoon I tried to start car turned on ignition and it turned a fraction not enough to start car then everything was dead not even a light showing, so I thought flat battery, I then connected charger to terminals under bonnet as I had done before, the charger sparked rather a lot, I left it connected for a few seconds but it started to smoke I then
opened boot via internal pull cord, the voltage across the battery was 0.71 volts , this was only after say 3 minunites that it started to turn over ??
I left it until now as we had to go out in the van, anyway, I have just removed battery and across the battery cables with it removed the resistance measures 0.7 ohms with the meter set on the 200 ohm scale.
the battery measures 3v, I am now leaving it on charge ( had to buy a new charger as the old one only now measures 5.6 volts) I even removed satnav
and the resistance is still 0.7 ohms, the car has been inside the garage for a while and has not seen water for quite a while, maybe I have a major short ?
I am in the AA but not home start, I asked an AA man in halfords if You can pay the extra instantly for them to come out if you have a problem he says yes, so what next, ? Do I connect the charged up battery and see what happens ( thats if its still ok, the black light was showing as it always does ) I May disconnect sat nav when I reconnect ) One thought, as it went whilst starting car could it be the starter solonoid shorting ????

hans.schaaper · 1st March 2009, 20:18

If you measure 0.7 ohms that means a dead short somewhere.
I would certainly NOT reconnect the battery.
You could pull fuses and measure again.
Don't know how hard it is to disconnect the starter and alternator.

Hans

geoff11 · 1st March 2009, 20:56

What I can do tomorrow is get someone to keep there eye on the meter set to ohms and start pulling fuses and relays, there is no sign of a fuse on the starter circuit only a 50 A link that goes to the ignition switch ?

hans.schaaper · 1st March 2009, 21:38

It must be a short of some kind.
A power consumer behind a fuse would not drain your battery in that short a period of time, that is without blowing the fuse.
Do NOT reconnect your battery it could cause a fire or your battery to explode.
Disconnecting the alternator should be easy.

Hans

Departed · 2nd March 2009, 06:58

You can't rely on a multimeter to measure the resistance of the car. There are lots of systems with capacitors, for example, that will try to charge up from the power your meter supplies.

This doesn't mean there isn't a problem, just that a meter isn't the way to check it.

geoff11 · 2nd March 2009, 18:46

Well its fixedI called the AA out this morning, it was the first 260 he had seen, I dont think he knew they even existed, firstly I removed the sat nav so as not to ruin it, and also removed ignition key, when he connected a good battery there was a big spark and the engine started to turn ??
He thinks it could have been a faulty relay on the push button engine start Kit ,so that was disconnected and everything was fine, we then refitted my original battery that I had charged overnight, it worked fine, then he tested it by removing the fuel pump fuse and letting me turn engine over for 15 seconds, all was fine battery good , then the alternator was tested all ok, and then we fitted sat nav all fine, finally after the sat nav had switched off he used a special clamp meter to test for leak down and every thing was good so I think the battery was quite flat when i tried to start it in the afternoon plus the relay could be dickey, I will replace with a new one.
Thumbs up for the AA though very professional approach, he was taken aback with the print outs I did of the fuse positions and locations, He said some blokes know nothing about the car they drive.

Kandyman · 2nd March 2009, 19:07

Glad to hear things are back to normal

1st March 2009, 19:33	#1
geoff11 Loves to post ZT 260 Join Date: Mar 2007 Location: Stroud Glos Posts: 258 Thanks: 0 Thanked 0 Times in 0 Posts	Possible major electrical problem Strange one this, this morning I replaced my passenger mirror with the bullet type and all was well had the ignition on and off a few times switched everything off and had lunch. this afternoon I tried to start car turned on ignition and it turned a fraction not enough to start car then everything was dead not even a light showing, so I thought flat battery, I then connected charger to terminals under bonnet as I had done before, the charger sparked rather a lot, I left it connected for a few seconds but it started to smoke I then opened boot via internal pull cord, the voltage across the battery was 0.71 volts , this was only after say 3 minunites that it started to turn over ?? I left it until now as we had to go out in the van, anyway, I have just removed battery and across the battery cables with it removed the resistance measures 0.7 ohms with the meter set on the 200 ohm scale. the battery measures 3v, I am now leaving it on charge ( had to buy a new charger as the old one only now measures 5.6 volts) I even removed satnav and the resistance is still 0.7 ohms, the car has been inside the garage for a while and has not seen water for quite a while, maybe I have a major short ? I am in the AA but not home start, I asked an AA man in halfords if You can pay the extra instantly for them to come out if you have a problem he says yes, so what next, ? Do I connect the charged up battery and see what happens ( thats if its still ok, the black light was showing as it always does ) I May disconnect sat nav when I reconnect ) One thought, as it went whilst starting car could it be the starter solonoid shorting ????

1st March 2009, 20:18	#2
hans.schaaper Avid contributor rover 75 2.5 V6 auto Join Date: Feb 2008 Location: Alkmaar Posts: 197 Thanks: 0 Thanked 3 Times in 3 Posts	If you measure 0.7 ohms that means a dead short somewhere. I would certainly NOT reconnect the battery. You could pull fuses and measure again. Don't know how hard it is to disconnect the starter and alternator. Hans

1st March 2009, 20:56	#3
geoff11 Loves to post ZT 260 Join Date: Mar 2007 Location: Stroud Glos Posts: 258 Thanks: 0 Thanked 0 Times in 0 Posts	What I can do tomorrow is get someone to keep there eye on the meter set to ohms and start pulling fuses and relays, there is no sign of a fuse on the starter circuit only a 50 A link that goes to the ignition switch ?

1st March 2009, 21:38	#4
hans.schaaper Avid contributor rover 75 2.5 V6 auto Join Date: Feb 2008 Location: Alkmaar Posts: 197 Thanks: 0 Thanked 3 Times in 3 Posts	It must be a short of some kind. A power consumer behind a fuse would not drain your battery in that short a period of time, that is without blowing the fuse. Do NOT reconnect your battery it could cause a fire or your battery to explode. Disconnecting the alternator should be easy. Hans

2nd March 2009, 06:58	#5
Departed Retired -- Join Date: Jan 2007 Location: -- Posts: 3,785 Thanks: 0 Thanked 4 Times in 4 Posts	You can't rely on a multimeter to measure the resistance of the car. There are lots of systems with capacitors, for example, that will try to charge up from the power your meter supplies. This doesn't mean there isn't a problem, just that a meter isn't the way to check it.

2nd March 2009, 18:46	#6
geoff11 Loves to post ZT 260 Join Date: Mar 2007 Location: Stroud Glos Posts: 258 Thanks: 0 Thanked 0 Times in 0 Posts	Well its fixedI called the AA out this morning, it was the first 260 he had seen, I dont think he knew they even existed, firstly I removed the sat nav so as not to ruin it, and also removed ignition key, when he connected a good battery there was a big spark and the engine started to turn ?? He thinks it could have been a faulty relay on the push button engine start Kit ,so that was disconnected and everything was fine, we then refitted my original battery that I had charged overnight, it worked fine, then he tested it by removing the fuel pump fuse and letting me turn engine over for 15 seconds, all was fine battery good , then the alternator was tested all ok, and then we fitted sat nav all fine, finally after the sat nav had switched off he used a special clamp meter to test for leak down and every thing was good so I think the battery was quite flat when i tried to start it in the afternoon plus the relay could be dickey, I will replace with a new one. Thumbs up for the AA though very professional approach, he was taken aback with the print outs I did of the fuse positions and locations, He said some blokes know nothing about the car they drive.

2nd March 2009, 19:07	#7
Kandyman Banned ROVER 75 2.5 V6 Connoisseur SE Limousine 2004 Join Date: Oct 2006 Location: Welling Posts: 10,995 Thanks: 0 Thanked 2 Times in 2 Posts	Glad to hear things are back to normal