Chargeing problems

[peter h]

Hi there.Ive got a 1984 t25 1900 petrol van conversion.The battery holds a charge for a few days.Ive replaced the battery with a 580 amp battery.I thought that the alternator was faulty also because as i started the van the battery voltage dropped to about 10.5.when van was running the voltage held at a steady 12.4.I fitted a new 45amp alt and replaced all earth leads but the problem is still there.Voltage at battery when van running is 12.4.\switch on any electrics and it drops away down.Is the new alternater faulty or should i upgrade to a 65amp alt

[Red Westie]

Nominal battery voltage 12 -12.6volts should increase instantly to between 13.9-14.2 when the engine is started and the red charge light goes out.
Your battery simply is not recieving charge from the alternator...either there is a breakin the main lead or earth (unlikely) or you have a faulty alternator (voltage regulator/bush pack)
Martin

[peter h]

Hi and thank you for the quick responce.The main lead.do you mean the lead from the pos of the battery to the starter etc.The van ticks over at 12.4 and when i rev the van it holds steady at 12.4.Im not clued up on elecs and just want to double check before i start

[peter h]

Nominal battery voltage 12 -12.6volts should increase instantly to between 13.9-14.2 when the engine is started and the red charge light goes out.
Your battery simply is not recieving charge from the alternator...either there is a breakin the main lead or earth (unlikely) or you have a faulty alternator (voltage regulator/bush pack)
Martin

Hi again.The main lead that you mentioned,it that the one from the battery to where.Wish i was an electrition

[VWCamperfan]

Right...!
From the alternator the power is taken to one of the posts on the solenoid of the startor motor. Also connected to that post is the thick lead that runs from your batterys + terminal.
Is your charging light coming on when engine is running? If it is then this could well be an alternator problem. If it isn't then its probably a cable or connection problem somewhere between the alternator and battery.
Make sure all connections (alternator connector, solenoid post and battery) are all clean and tight.
Make sure all connections (alternator firmly clamped to engine, earth strap from body to gearbox and earth strap from body to battery) are also clean and tight.
If your battery is low on charge then expect to find the charging voltage isn't quite up to what it should be. 13.8 volts is about what you need for a good charge with a lead acid battery. A few tenths over shouldn't do any harm but anything below could indicate a problem.

[peter h]

Right...!
From the alternator the power is taken to one of the posts on the solenoid of the startor motor. Also connected to that post is the thick lead that runs from your batterys + terminal.
Is your charging light coming on when engine is running? If it is then this could well be an alternator problem. If it isn't then its probably a cable or connection problem somewhere between the alternator and battery.
Make sure all connections (alternator connector, solenoid post and battery) are all clean and tight.
Make sure all connections (alternator firmly clamped to engine, earth strap from body to gearbox and earth strap from body to battery) are also clean and tight.
If your battery is low on charge then expect to find the charging voltage isn't quite up to what it should be. 13.8 volts is about what you need for a good charge with a lead acid battery. A few tenths over shouldn't do any harm but anything below could indicate a problem.

[peter h]

Right...!
From the alternator the power is taken to one of the posts on the solenoid of the startor motor. Also connected to that post is the thick lead that runs from your batterys + terminal.
Is your charging light coming on when engine is running? If it is then this could well be an alternator problem. If it isn't then its probably a cable or connection problem somewhere between the alternator and battery.
Make sure all connections (alternator connector, solenoid post and battery) are all clean and tight.
Make sure all connections (alternator firmly clamped to engine, earth strap from body to gearbox and earth strap from body to battery) are also clean and tight.
If your battery is low on charge then expect to find the charging voltage isn't quite up to what it should be. 13.8 volts is about what you need for a good charge with a lead acid battery. A few tenths over shouldn't do any harm but anything below could indicate a problem.

Hi its pete again.Thanks for the great info.Will check all conections tomorrow and ill let you know how i get on.many thanks again

[Red Westie]

Bosch alternator circa mid 80's were regulated between 13.9 and 14.2volts so 13.8 is actually a little on the low side. Admitedly should still be OK (says this on the pink BOSCH label) sounds to me like you need a new alternator or perhaps you may be able to get away with just the regulator bush pack which can be found for under a tenner.
Martin