Won't start from cold...

[jimothy]

Just got back from 2 weeks away and decided to fire up the beast and give him a nice run to say sorry for leaving him so long.

So I get in and turn the key. Things light up and the fuel pump starts as normal, but the starter motor doesn't fire, same as the good old hot start problem - apart from lack of hottness of course.

Unfotunately I'm on my todd at the moment so no-one to give me a push start to see if it is the starter motor, but can anyone give me some suggestions for things to check (fuses and the like). Oh, and I'm rubbish with cars so anything that involves long words, getting underneath or an IQ above about 6 is waaaayyyy beyond me.

Thanks guys.

[Steve_T]

Dying battery - i.e. enough to supply a small current, but not enough to supply a few hundred amps to the starter? Have you tested it with a voltmeter?

[jimothy]

runs to maplin to get a multimeter

[Steve_T]

BTW do you mean won't start from cold, or won't start at all?

[V8 Archie]

Steve_T said:

BTW do you mean won't start from cold, or won't start at all?

I get the impression that he doesn't know if it will start from hot or not yet.

[jimothy]

Back from Maplin with multimeter in hand, and it's coming out at 11.39 voltamathingies.

Is this lots or not enough?

[Steve_T]

Not enough - 12.7 - 12.8 is a healthy fella. First step is either to jump it from a suitable vehicle (needs a chunky battery that has a crank rating of 600A or so) or alternatively charge it up. In that state of discharge it'll take a while. If you can get it to run, measure the voltage across the battery when the engine is running. This will tell you if the alternator is charging the battery or not. The voltage should be > 13v with the engine running, it may well be closer to 13.5v.

[jimothy]

Right, tried to charge the battery, but it wouldn't take a charge. Fitted a new one, and it's looking good, voltages appear to do what they should, 12.7 when switched off, jumping up when the engine's started.

Thanks for the help.