Electrical problems
Discussion
Hi all,
I am having some electrical problems on my S or so I think.
Scenario: Rainy day like today start the car no problem this morning. Started driving in the rain with wipers on, so far so good. My windows are stuck in high position, have to change the weather channels for a while now but still didn't have the time to do it so I cannot open them.
Now it gets very foggy inside and the windshield gets opaque very fast. Now I put the fan on to max position and then I noticed that the engine was not running fine. Rattling and suddenly cut when I stop...
When I look at the battery indicator when the heater is on, I notice the needle is in the red... So I am not sure that is normal but that could be related to my engine idling problems I have had in the past. When the car gets hot and the fan kicks in, the idle goes down and the car seems to have problems staying alive... Have to leave my foot on the pedal to make sure it does not stall... Do you think there might be an earth somewhere? Is that something anybody experienced before?
I have been told by the garage I left my car with that the immobiliser seems to be interfering with the engine but I didn't pay attention to that at the time. It could be related... Anybody knows someone in the Hampshire area (more towards Portsmouth) that could take the alarm/immobiliser out for me? It seems it had been installed by someone rather than someone that knows what they were doing
aXe
I am having some electrical problems on my S or so I think.
Scenario: Rainy day like today start the car no problem this morning. Started driving in the rain with wipers on, so far so good. My windows are stuck in high position, have to change the weather channels for a while now but still didn't have the time to do it so I cannot open them.
Now it gets very foggy inside and the windshield gets opaque very fast. Now I put the fan on to max position and then I noticed that the engine was not running fine. Rattling and suddenly cut when I stop...
When I look at the battery indicator when the heater is on, I notice the needle is in the red... So I am not sure that is normal but that could be related to my engine idling problems I have had in the past. When the car gets hot and the fan kicks in, the idle goes down and the car seems to have problems staying alive... Have to leave my foot on the pedal to make sure it does not stall... Do you think there might be an earth somewhere? Is that something anybody experienced before?
I have been told by the garage I left my car with that the immobiliser seems to be interfering with the engine but I didn't pay attention to that at the time. It could be related... Anybody knows someone in the Hampshire area (more towards Portsmouth) that could take the alarm/immobiliser out for me? It seems it had been installed by someone rather than someone that knows what they were doing
aXe
Axe,
Re: the alaqrm question - I would check the TVR general forum and do a search on alarms. There is a guy in Petersfield (area) who has a v.good reputation and amy be able to help.
Re: the heater problem I would check/clean all the Earths on the chassis - check the output of the alternator (should be > 13.6 volts) - clean the blade fuse for the heater.....as a start.
If that doesn't improve the situation then get an auto sparks to sdig a bit deeper. Good luck.
Nick
Re: the alaqrm question - I would check the TVR general forum and do a search on alarms. There is a guy in Petersfield (area) who has a v.good reputation and amy be able to help.
Re: the heater problem I would check/clean all the Earths on the chassis - check the output of the alternator (should be > 13.6 volts) - clean the blade fuse for the heater.....as a start.
If that doesn't improve the situation then get an auto sparks to sdig a bit deeper. Good luck.
Nick
Any electrical load will cause the Alternator to put a load on the engine, which in turn will try and slow it down.I would expect the revs to drop initially but then return to normal as the management system detects the drop and corrects it.If the battery is in poor condition this will be exagerated.
Bad earths will reduce the current taken by the "load" so would have less effect on the engine speed.I would suggest either the tickover is too low or the slow running devices are not reacting correctly.
Bad earths will reduce the current taken by the "load" so would have less effect on the engine speed.I would suggest either the tickover is too low or the slow running devices are not reacting correctly.
it was just after driving to work this am so it has been said on the forums that it should show 13.6V odd...
So nothing too obvious there, the voltmeter in the car is always below 13V when running and drops when the fan kicks in...
I should hard-wire the new voltmeter in place and keep checking it while driving
aXe
So nothing too obvious there, the voltmeter in the car is always below 13V when running and drops when the fan kicks in...
I should hard-wire the new voltmeter in place and keep checking it while driving
aXe
Just for reference ive just checked my battery,which has been sitting in the shed for 3 months and it reads 12.6v
Either your meter is iffy or i suspect your battery is
Have you got another car you can check the battery the readings should be te same
Either your meter is iffy or i suspect your battery is
Have you got another car you can check the battery the readings should be te same
Edited by Pies on Monday 9th October 14:17
Read this www.sailgb.com/sshop/tech_info.asp?ID=223 i know its a boat site but ignore that 
read the section BATTERY PERFORMANCE
now you will hopefully see what i mean about rechecking the battery and meter cos one of the two seems duff
www.picbasic.org/forum/archive/index.php/t-5940.html
read the section BATTERY PERFORMANCE
now you will hopefully see what i mean about rechecking the battery and meter cos one of the two seems duff
www.picbasic.org/forum/archive/index.php/t-5940.html
Edited by Pies on Monday 9th October 15:26
Hi Axe,
did you have any luck sorting the problem?
My S3 does exactly the same. Cleaned all earth and battery connections, checked the battery etc which was running fine (and is new!). Still no joy. When I have the headlights on the voltmeter goes to the . just above the red, then with brake lights, indicators and wipers etc it drops to the red. If the fan cuts in or I switch on the heater it's goodnight vienna. Spent much time trying to solve the problem but to no avail.
Any developments on yours would be good to know!
did you have any luck sorting the problem?
My S3 does exactly the same. Cleaned all earth and battery connections, checked the battery etc which was running fine (and is new!). Still no joy. When I have the headlights on the voltmeter goes to the . just above the red, then with brake lights, indicators and wipers etc it drops to the red. If the fan cuts in or I switch on the heater it's goodnight vienna. Spent much time trying to solve the problem but to no avail.
Any developments on yours would be good to know!
nope sorry haven't got any further with the problem 
I just keep the foot on the gas and maintain a 1200+ rpm when stopped in the dark and wet weather...
I am leaving the UK for France in a few days and I am taking the old lady with me. I have a friend of mine who owns a garage and loves this sort of car. He told me he'll store it for me and will give a few looks here and there trying to figure what is wrong. I am pretty sure there is an earth somewhere but cannot put the finger on it.
I noticed the battery light comes timidly when the headlights are on and pulses when the wipers are on. If I indictate as well it pulses a bit brighter... Hence why I thought about a bad contact somewhere...
But I'll keep you posted if I manage to find a cure, hope you will do the same
aXe
I just keep the foot on the gas and maintain a 1200+ rpm when stopped in the dark and wet weather...
I am leaving the UK for France in a few days and I am taking the old lady with me. I have a friend of mine who owns a garage and loves this sort of car. He told me he'll store it for me and will give a few looks here and there trying to figure what is wrong. I am pretty sure there is an earth somewhere but cannot put the finger on it.
I noticed the battery light comes timidly when the headlights are on and pulses when the wipers are on. If I indictate as well it pulses a bit brighter... Hence why I thought about a bad contact somewhere...
But I'll keep you posted if I manage to find a cure, hope you will do the same
aXe
Hi,
You seem to have a duff alternator or faulty earth connection for the alternator: if the voltmeter on the dashboard reads too low this could well be a bad earth, but if it reads too high this generally means the alternator really is charging at a high voltage. Secondly, if the charging light comes on, this means the field coils in the alternator are drawing more current then its stator puts out: also a sign of a duff rectifier/voltage regulator in the alternator.
The alternator finds its earth through the engine earth strap, so I would check this first, although if the earth strap would be bad, the starter would also spin slower. Second thing to check is the alternator itself: pull all the wires from the alternator (watch out, these are live wires), isolate them well (sparking from a live wire could easily set your P&J on fire). Then drive the car for a few minutes with lights, foglamps, heater and everything else on, till the fan kicks in. If the bad running has disappeared, the rectifier/voltage regulator in the alternator apparently is dead.
With a full battery in good condition you should be able to run the car for at least 15 minutes.
I hope this advise will help you a bit!
Cheers,
Ronald
You seem to have a duff alternator or faulty earth connection for the alternator: if the voltmeter on the dashboard reads too low this could well be a bad earth, but if it reads too high this generally means the alternator really is charging at a high voltage. Secondly, if the charging light comes on, this means the field coils in the alternator are drawing more current then its stator puts out: also a sign of a duff rectifier/voltage regulator in the alternator.
The alternator finds its earth through the engine earth strap, so I would check this first, although if the earth strap would be bad, the starter would also spin slower. Second thing to check is the alternator itself: pull all the wires from the alternator (watch out, these are live wires), isolate them well (sparking from a live wire could easily set your P&J on fire). Then drive the car for a few minutes with lights, foglamps, heater and everything else on, till the fan kicks in. If the bad running has disappeared, the rectifier/voltage regulator in the alternator apparently is dead.
With a full battery in good condition you should be able to run the car for at least 15 minutes.
I hope this advise will help you a bit!
Cheers,
Ronald
Axe,
wrote the warning in haste. There are six diodes in the alternator one or more may be damaged (perhaps because of a bad connection). You then have an alternator with limited power. And with the remaining diodes under more load.
I would check all connections in the path alternator+ / battery / earth /altrnator housing (= alternator-)
You can do this by inspection.
Or eaasier run the engine at 2000 rpm and measure the voltage drop across each connection. A high resistance one will show up as a high voltagedrop (> say 0.1 V at 10 amps). If the connections can be improved, you are lucky.
If the connections were not the cause, I would take out the alternator and have it checked by a car electrics firm. They have a test rig they mount the alternator on, run it and measure it. Takes 10 minutes in the shop. Then you may or may not need a reconditioned alternator, which should be something like EUR 150.
When you re-assembly clean contacts, use plenty of grease against future contact corrosion.
Also charge the battery soonest with an electrical charger, since a low charge is bad for it's life expectancy. But since it still starts the car it is basically OK.
The battery light is wired in my car as in an old DC dynamo, hence the selfstarting of S alternators, only at 2000+ rpm. So the significance of that light is different compared with correctly wired car with alternators.
mng Boudewijn
wrote the warning in haste. There are six diodes in the alternator one or more may be damaged (perhaps because of a bad connection). You then have an alternator with limited power. And with the remaining diodes under more load.
I would check all connections in the path alternator+ / battery / earth /altrnator housing (= alternator-)
You can do this by inspection.
Or eaasier run the engine at 2000 rpm and measure the voltage drop across each connection. A high resistance one will show up as a high voltagedrop (> say 0.1 V at 10 amps). If the connections can be improved, you are lucky.
If the connections were not the cause, I would take out the alternator and have it checked by a car electrics firm. They have a test rig they mount the alternator on, run it and measure it. Takes 10 minutes in the shop. Then you may or may not need a reconditioned alternator, which should be something like EUR 150.
When you re-assembly clean contacts, use plenty of grease against future contact corrosion.
Also charge the battery soonest with an electrical charger, since a low charge is bad for it's life expectancy. But since it still starts the car it is basically OK.
The battery light is wired in my car as in an old DC dynamo, hence the selfstarting of S alternators, only at 2000+ rpm. So the significance of that light is different compared with correctly wired car with alternators.
mng Boudewijn
Hi Boudewijn,
You're right not to run the alternator without the +30 connected, but taking off the +15 will cut power to the field coils, so the power output will be zero (theoretically the residual magnetism could make the alternator work, but then the revs have to be so high, you'll blow up the engine before there's any output on the +30 line).
Cheers,
Ronald
You're right not to run the alternator without the +30 connected, but taking off the +15 will cut power to the field coils, so the power output will be zero (theoretically the residual magnetism could make the alternator work, but then the revs have to be so high, you'll blow up the engine before there's any output on the +30 line).
Cheers,
Ronald
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