Battery/alternator issues

[Jackg123]

Hi guys I’ve recently brought a 172 cup roughly 3 weeks.I’ve replaced the battery and alternator. It had been running fine but this morning it died on me, Radio went off and lights on dash lit up like a Xmas tree. Left 10 mins started fine but as soon I put lights on it died again. I checked my battery voltage and getting 8 volts. Any ideas. Like I said new battery/ alternator any ideas ?

 

[Mbeau]

Have you measured the voltage across the battery when the car is running? Bit strange it would not start and then after ten mins it would. That would prob be down to a bad earth.

Is the battery earth strap tight on the terminal? Still would not answer why you only had 8 volts though?

If the alternator is charging then it's a bad earth or battery I would suspect. If not charging then bad connection or alternator. It's not uncommon for new alternator or battery to fail.

 

[Jackg123]

hi yeah I got 8v with the car running with no load when I switch the lights, radio and heater it drops to about 6v,.I’ve replaced the the battery connectors to the terminals as they were a little loose. The strange thing is the battery and stop light on dash doesn’t light up when I start car which it did before when alternator was knackered. U

 

[Brigsy]

Check the small exciter wire is connected up to the alternator, as they can break resulting in no battery light/charge. if the wiring checks out ok, assume alternator is dead

 

[Jackg123]

Check the small exciter wire is connected up to the alternator, as they can break resulting in no battery light/charge. if the wiring checks out ok, assume alternator is dead

Thanks will check that out, only replaced alternator 2 weeks ago!!!

 

[Krarl]

If you're only getting 8v when the car is running then the issue lies with the alternator or a wiring issue mate

 

[Jackg123]

Check the small exciter wire is connected up to the alternator, as they can break resulting in no battery light/charge. if the wiring checks out ok, assume alternator is dead

Thanks will check that out

If you're only getting 8v when the car is running then the issue lies with the alternator or a wiring issue mate

Thanks,I think it’s a trip back to the garage