Battery or Alternator problem
 

Hello

I am after a bit of help, please.
I have a 53 Reg 75 2.0 Cdt and recently the battery has started running flat. I put the battery on charge until full and it runs great (1st turn of the key) and then it all of a sudden when I stop the car it will not start again and the EP light comes on the dashboard.

Not sure if it is the battery or the alternator.

Any ideas?

Finbar

Sounds like the battery, how old is it ?

Do you have a test meter to test voltage? If you do, what voltage are you getting across the battery terminals? With the car running what do you get across the battery terminals?
If you don't have a tester, fully charge the battery off the car, then disconnect the battery and leave it for a few days, then try connecting it back to the car and see how it starts.

macafee2

You should, with a voltmeter, get 12.5 to 12.7 volts at rest and over 14.00 volts with engine running

Thanks for the info getting a voltmeter tomorrow.

get one that can measure amps as well.


macafee2

Just hope it's the battery , the alternator on a diesel is a pain to change :duh:

Okay Lads Im stumped,

The car did a 300 miles run out on Friday evening and return journey of 300 miles return journey on Sunday. The car has been stood on the drive.

Today (Wednesday) the voltage on the battery with engine not started was showing at 13.0 - 13-1V

When the car was started and running 14.5 - 14.6V
When all lights, heater, radio etc on 14.5V

I am thinking that the battery is slowly loosing its charge over time. When I use the car it is generally little runs around the doors.


Any ideas
Finbar

Well on those figures the battery looks ok- so re test again after leaving a day or two to see what voltage is being lost - you may have a battery drain or it could be your alternator diodes(s) failing. A failing alternator diode can drain your battery.

Is it an old alternator?

The diodes in the alternator convert alternating current produced by the running of the engine to direct current for use by the battery. So if your alternator is producing any AC it is faulty. Set your voltmeter to the wavy V setting (V with a wavy line) - set to the lowest setting - switch your engine on and attach your voltmeter to your battery terminals - if an AC voltage is detected then your alternator diodes are failing.

If the alternator is fine - you may have a battery drain caused by shorting or earthing wires/looms or have you fitted anything new to the car gadget wise - also check when parked up are any lights still on in the car.

Well that could be your answer, lots of short runs with cold starts and heater, heated rear screen and lights on.

Under those circumstances the battery would struggle to survive .