Battery Output anyone??

LLM

Anyone any good with cars?

Been having a few problems with our 07 plate Fiesta of a morning, it's taking a few phases to start. Also, the thermometer has gone a bit bonkers, sometimes it doesn't register the temperature at all, then other times, it's -38!

We've had a mechanic give it the once over as hubby thought it may be the glow plugs but mechanic says he cannot find a problem.

Hubby has looked today at some diagnostics thing on the in car computer, and it says that the battery output is '14.2'... anyone have any idea what this means? Could we need a new battery or is this normal?!

Thanks in advance!

LLM

Think I may have solved this mystery... its volts isn't it?!

bryanb

It is volts, but it must be the alternator output.
It's the max output for a normal alternator. Measure the battery voltage when engine hasn't run for a few hours and tell us the result.

forgotmyname

Thats volts yes. 14.2 volts is OK with the engine running but whats it like with the engine off and under load?

External temperature sensor probably got corroded terminals. Clean them or replace the sensor. Its under £20.

Taking a few phases.. Explain in more detail what exactly happens?

Diesel?

swiftnick

The Thermometer is for ambient temperature, nothing to do with the poor starting issue.

Does is crank healthy but not fire? If so you may have a problem with the pre heat side of things.

Strider590

swiftnick wrote: »

The Thermometer is for ambient temperature, nothing to do with the poor starting issue.

Does is crank healthy but not fire? If so you may have a problem with the pre heat side of things.

Well actually if the battery is on it's last legs, when you start the car the voltage drops too far and can cause problems with the instrument cluster, because the instrument cluster is supplied by a linear voltage regulator (probably around 5v for ttl circuits), these voltage regulators need a supply of at least 2 volts higher than their output, else they shutdown.

2 days before mine gave up (2yrs ago) the dash stopped working altogether, no speed, no rpm, no display, no nothing.

LLM

Thanks all, will see if my father in law has a battery meter and we can see what the battery is reading at.

It is a diesel.

swiftnick, when I say thermometer, I mean the sensor that measures the outside temperature.

LLM

Also, to clarify, when the engine is cold, we turn the key, and it cranks but doesn't start, so we have to turn the key again, sometimes it starts second time, sometimes we have to do it a third time

spacey2012

When was the fuel filter last replaced ?
They collect water which can freeze

Lum

It's an 07 so that battery, unless it's previously been replaced, is going to be six years old by now, so probably due a replacement. It should have a sticker on it saying when it was manufactured?

But yes as others have said, check the voltage with the engine not running and report back.

Rover_Driver

LLM wrote: »

Also, to clarify, when the engine is cold, we turn the key, and it cranks but doesn't start, so we have to turn the key again, sometimes it starts second time, sometimes we have to do it a third time

That is not uncommon with a diesel in the cold weather, you have to give the glow plugs time to warm up.