Aston Martin Virage 2012 not starting on full battery power
Discussion
leman600 said:
If you take a jump lead from the battery earth to the engine bay earth point you were using and try to start then. I havn't an electrical drawing but I think you should spend an hour to at least rule earthing out. It's easy and quite likely the problem.
^ This is exactly where I'd be starting to.Are you jump starting by connecting the booster pack negative cable to a good engine earth and the booster pack positive cable to a heavy duty positive jump start connector similar to the one shown in the following video?
Aston Martin DB9 V12 Jump Start
If the above is the case, you are bypassing the main engine earth and the whole vehicles battery positive supply circuit
There is no point in removing the alternator for further testing as it may well prove to be functioning correctly once the starter motor circuit fault is rectified
As mentioned by other posters, there is the possibility of an engine earth failure and that can be tested with a voltmeter connected between the battery negative and the engine block, the meter shouldn't show more than 0.75 of a volt voltage-drop when the starter is operated (in your vehicles case, when the solenoid has clicked in)
If the engine earth has failed the voltmeter connected as above will read close to battery voltage (12 volts)
If the engine earth proves to be good, check the following battery disconnect circuit as shown with starter solenoid clicked in
There is nothing to gain by measuring voltages without the starter button being pressed at the time of testing, voltages are often present without the starter motor or starter solenoid load on the circuit
Don't have a booster pack connected when carrying out the above tests, rely on a fully charged vehicle battery
If the above two tests show everything to be good, there is a blown main battery fuse in the circuit between the battery and starter motor or a failed main positive supply cable from battery to starter motor
The only other possibility for the loss of rear to front battery positive supply would be the failure of a master switch that somebody has previously wired into the battery cable
Aston Martin DB9 V12 Jump Start
If the above is the case, you are bypassing the main engine earth and the whole vehicles battery positive supply circuit
There is no point in removing the alternator for further testing as it may well prove to be functioning correctly once the starter motor circuit fault is rectified
As mentioned by other posters, there is the possibility of an engine earth failure and that can be tested with a voltmeter connected between the battery negative and the engine block, the meter shouldn't show more than 0.75 of a volt voltage-drop when the starter is operated (in your vehicles case, when the solenoid has clicked in)
If the engine earth has failed the voltmeter connected as above will read close to battery voltage (12 volts)
If the engine earth proves to be good, check the following battery disconnect circuit as shown with starter solenoid clicked in
There is nothing to gain by measuring voltages without the starter button being pressed at the time of testing, voltages are often present without the starter motor or starter solenoid load on the circuit
Don't have a booster pack connected when carrying out the above tests, rely on a fully charged vehicle battery
If the above two tests show everything to be good, there is a blown main battery fuse in the circuit between the battery and starter motor or a failed main positive supply cable from battery to starter motor
The only other possibility for the loss of rear to front battery positive supply would be the failure of a master switch that somebody has previously wired into the battery cable
Edited by Penelope Stopit on Thursday 31st December 12:35
Glad to possibly be of some help, it's not everyday that someone posts such a simple fault caused by such a complicated circuit
No there shouldn't be any problems caused by connecting the booster negative cable to the alternator casing/bracket as long as the alternator brackets/mounting points are directly or indirectly bolted to the engine block. The alternator casing should be a good negative
I doubt there will be a negative jump starting point in the engine bay as there is nothing better than connecting directly to the engine block
No there shouldn't be any problems caused by connecting the booster negative cable to the alternator casing/bracket as long as the alternator brackets/mounting points are directly or indirectly bolted to the engine block. The alternator casing should be a good negative
I doubt there will be a negative jump starting point in the engine bay as there is nothing better than connecting directly to the engine block
Penelope Stopit said:
Glad to possibly be of some help, it's not everyday that someone posts such a simple fault caused by such a complicated circuit
No there shouldn't be any problems caused by connecting the booster negative cable to the alternator casing/bracket as long as the alternator brackets/mounting points are directly or indirectly bolted to the engine block. The alternator casing should be a good negative
I doubt there will be a negative jump starting point in the engine bay as there is nothing better than connecting directly to the engine block
Seconded, no issues there.No there shouldn't be any problems caused by connecting the booster negative cable to the alternator casing/bracket as long as the alternator brackets/mounting points are directly or indirectly bolted to the engine block. The alternator casing should be a good negative
I doubt there will be a negative jump starting point in the engine bay as there is nothing better than connecting directly to the engine block
Also proves that the engine earth strap is good.
Remembering the starter motor also earths via direct contact through the block, via the earth strap to the body.
Hutch525 said:
Seconded, no issues there.
Also proves that the engine earth strap is good.
Remembering the starter motor also earths via direct contact through the block, via the earth strap to the body.
Didn't mean to be repeating with my above post what you have already posted earlier, have somehow not read a few posts on page 1 including those from yourself and some from Norwich77, sorry about that, happy new yearAlso proves that the engine earth strap is good.
Remembering the starter motor also earths via direct contact through the block, via the earth strap to the body.
Penelope Stopit said:
Didn't mean to be repeating with my above post what you have already posted earlier, have somehow not read a few posts on page 1 including those from yourself and some from Norwich77, sorry about that, happy new year
Don't worry about it 
If we can collectively help find the issue then that is the goal.
Its good to see people willing to take on the maintenance and fault finding themselves.
It increases their understanding of the car and reduces the fear factor when things go wrong.
Somethings still need dealer support obviously and some things are beyond what you would class as normal DIY,
But there are enough people on the forum who have an engineering background and or enough mechanical/electrical expertise who are willing to support anyone with some knowledge transfer.
Astons although special are no more complicated than any other vehicle.
Hello chaps,
I’m pretty excited to same we have some positive discussion finally,
I Brought some jumps leads home from work, had to put two leads together to get a safe length to not risk marking body.
So connected one end to negative on battery and the other end to the alternator bracket (same place the jump starter will jump from) as advised here.
And hey presto it started from the battery alone,
It was a very poor start like it was flat battery (but it isn’t flat) but it started, (is the weak starting because of jump lead length)
I left running about 3 minutes on jump leads, but have no test equipment to see if the alternator was now charging
The jump lead ends went luke warm.
So I’m guessing a bad earth battery end,
So can you help on what to check for now.
I’m excited something had made a difference to give us a clue what is going on.
I’m pretty excited to same we have some positive discussion finally,
I Brought some jumps leads home from work, had to put two leads together to get a safe length to not risk marking body.
So connected one end to negative on battery and the other end to the alternator bracket (same place the jump starter will jump from) as advised here.
And hey presto it started from the battery alone,
It was a very poor start like it was flat battery (but it isn’t flat) but it started, (is the weak starting because of jump lead length)
I left running about 3 minutes on jump leads, but have no test equipment to see if the alternator was now charging
The jump lead ends went luke warm.
So I’m guessing a bad earth battery end,
So can you help on what to check for now.
I’m excited something had made a difference to give us a clue what is going on.
Edited by Norwich77 on Monday 4th January 21:13
At the risk of teaching you to suck eggs, because the engine, torque tube and transaxle are on flexible (rubber) mountings they are effectively electrically isolated from the body. To overcome this there is a flexible earth strap somewhere between the engine and gearbox which simply bolts one end to the engine and the other to the body; usually these are just a braid.
If I understand you then the connections could have corroded or the braid could have frayed/broken from the relative movement between the two. If the strap is still intact then you may only have to unbolt the ends, clean the contact areas on both the strap and the part it’s bolted to and reconnect. What I can’t tell you is where the strap is on your car.
What you are doing by connecting the alternator bracket to the body is replicating the engine earth strap.
Apologies if this isn't helpful.
If I understand you then the connections could have corroded or the braid could have frayed/broken from the relative movement between the two. If the strap is still intact then you may only have to unbolt the ends, clean the contact areas on both the strap and the part it’s bolted to and reconnect. What I can’t tell you is where the strap is on your car.
What you are doing by connecting the alternator bracket to the body is replicating the engine earth strap.
Apologies if this isn't helpful.
Edited by LTP on Monday 4th January 22:36
Awesome news, huge step forward
So as others have said your problem is the earth of the engine to the body....
So next steps
Using a multi meter measure the resistance between the engine block(alt bracket) as a reference. Should be very close to zero ohms.
Engine earth strap is down the right hand side of the engine. And looks like :
Remove the bolt from one end, clean the bolt, the cable terminal and the ngine/body surface it bolts too with scotchbright or similar then refit.
Measure resistance again and see if it drops closer to zero.
Do the other end anyways while you're there no matter the reading and measure resistance again.
There is a second main earth on the transmission and I believe (but have not personally seen it) there is one on the torque tube ( someone please correct me if I'm Wrong)
Hope this sorts it out
So as others have said your problem is the earth of the engine to the body....
So next steps
Using a multi meter measure the resistance between the engine block(alt bracket) as a reference. Should be very close to zero ohms.
Engine earth strap is down the right hand side of the engine. And looks like :
Remove the bolt from one end, clean the bolt, the cable terminal and the ngine/body surface it bolts too with scotchbright or similar then refit.
Measure resistance again and see if it drops closer to zero.
Do the other end anyways while you're there no matter the reading and measure resistance again.
There is a second main earth on the transmission and I believe (but have not personally seen it) there is one on the torque tube ( someone please correct me if I'm Wrong)
Hope this sorts it out
Hutch525 said:
Could it be that if you're not getting alternator voltage back at the battery?
I had this issue once with an Aston - some 50p diode had failed, but it took a long while to diagnose.Maybe not the issue here, no idea, but running the car was draining the battery rather than charging it.
Nicely found
As long as the earth cable/cables are good, removing, cleaning and refitting all body to engine/transmission earth cables will get it up and running
Fitting new cables is a worthwhile job as you will have to remove the old ones to clean them
Jump leads are getting warm because they are not heavy enough for the current being drawn through them
As long as the earth cable/cables are good, removing, cleaning and refitting all body to engine/transmission earth cables will get it up and running
Fitting new cables is a worthwhile job as you will have to remove the old ones to clean them
Jump leads are getting warm because they are not heavy enough for the current being drawn through them
Edited by Penelope Stopit on Tuesday 5th January 09:48
I'd urge caution with using a multimeter measurement of resistance to check whether the connection is good. From a quick Google check a typical Varta battery for the Virage (95Ah Blue Dynamic) has a Cold Cranking Current (CCA) capability of 800A. From Ohm's Law, if you have a 12.6V battery passing current through an earth strap with a resistance of only 0.05 Ohms then the current will be 252A; if the resistance is up to only 0.3 Ohms then the current is restricted to 42A. Just get them sparking clean, tighten them and then maybe, once you know this has fixed the problem, give them a wipe over the top with waterproof grease to keep the connection dry going forward.
As the Virage has a bonded aluminium body (the first AM to use this, if memory serves) and I believe the earth fixing point will be a steel stud or nutsert which is crimped to the body, so if cleaning the contact points doesn't work then it is possible that if moisture has gotten into the crimped joint and set up a small electrochemical corrosion cell there could be electrical resistance between the actual threaded fastener in the body that the strap attaches to and the body itself.
As the Virage has a bonded aluminium body (the first AM to use this, if memory serves) and I believe the earth fixing point will be a steel stud or nutsert which is crimped to the body, so if cleaning the contact points doesn't work then it is possible that if moisture has gotten into the crimped joint and set up a small electrochemical corrosion cell there could be electrical resistance between the actual threaded fastener in the body that the strap attaches to and the body itself.
Edited by LTP on Tuesday 5th January 11:54
LTP said:
As the Virage has a bonded aluminium body (the first AM to use this, if memory serves) and I believe the earth fixing point will be a steel stud or nutsert which is crimped to the body, so if cleaning the contact points doesn't work then it is possible that if moisture has gotten into the crimped joint and set up a small electrochemical corrosion cell there could be electrical resistance between the actual threaded fastener in the body that the strap attaches to and the body itself.
Very good observation, hope you don't mind me commenting so, hope this isn't the case for the OPs sakeGassing Station | Aston Martin | Top of Page | What's New | My Stuff