11 replies to this topic

[exeterman2]

Hi all, so when I got in my car today my volt meter was showing 12V, however when I turned the key to start the car, the voltage on the volt meter dropped off completely. The voltage was fine when the key was in before trying for ignition. I last drove the car only a couple of days ago. Any ideas on what my solution might be?

[exeterman2]

Also forgot to mention that after waiting a few seconds the voltage came back up to 12V, then uponnturningnthe key again it dropped again and has stayed down since.

[mini13]

knackered battery,loose battery terminal, dodgy earth cable,

 

get a volt meter and try to trace wher the voltage "stops"

[dyshipfakta]

Battery is dead. 12v is a pretty much flat 12v battery. Ironic I realise but fully charged should be more like 13v.

Take it out give it a charge and check the earths

[gazza82]

Or dodgy ignition switch?

[Ethel]

Does sound like a dead battery. Volt meters don't tell you that much without any load on a circuit. See how bright the headlights are & check the battery cable connections +ve & -ve.

[Alpenflitzer]

Befor start the Voltmeter shows 13 V. After start my Voltmeter shows 13,5 to 13,8 Volt. In my opinion that is the correct value for generator. My battery is 2,5 years in use. I think it also depends on the efficiency of the generator. Measure when engine is idle at the battery poles, than switch on the lighting. The difference of measurement before and after should not be more than 0.5 to max 1 Volt.

[Ethel]

Ok,

 

I suppose we assumed it wasn't starting. The charging voltage does tell you something useful. Yes, raise the revs, above 2000rpm, and turn on the head lights to see if the alternator can keep up.

 

How your dash voltmeter is wired in has an effect. With the meter across the battery terminals you can be sure you're seeing the some of all voltage drops.

[exeterman2]

Thanks for all the replies. No the car wasn't starting, sorry should've specified to make it clearer. The volt meter was at just over 12V, in its normal position when the car is off. I checked the battery and it was fine. Putting the car and rocking it back and forth, brought the car back to life. Could this mean a dodgy earth somewhere? Or a problem with the starter motor?

[exeterman2]

*Putting the car in gear

[gazza82]

Thanks for all the replies. No the car wasn't starting, sorry should've specified to make it clearer. The volt meter was at just over 12V, in its normal position when the car is off. I checked the battery and it was fine. Putting the car and rocking it back and forth, brought the car back to life. Could this mean a dodgy earth somewhere? Or a problem with the starter motor?

Jammed starter pinion ...

[mini13]

sounds like the starter bushes are iffy,