Is My Battery Or Stater Motor Shagged?

[Mr Italy!]

Hey!

Recently ive had a few issues with either my battery or starter motor, or maybe a mixture of both.

Basically, if im sitting in the car with the engine off and the music on for say 15 minutes (or there abouts), when i attempt to start the car all i get is a clicking sound coming from the engine bay and it just wont start. I first assumed the battery was flat but i checked using the turbo timer and it says the battery still has 11.5V...

I dont have the first clue about how much power a starter motor requires to make it kick, but i would assume 11.5V should do the trick?

Any ideas as to whats going on?

Thanks guys!

[RANDY]

I'd be interested to see what your alternator is doing. If it's not charging the battery, then your amperage is going to suffer. (batteries are sometimes rated at "CA", Cranking Amps)

I dunno if the Skyline's alternator has a removeable voltage regulator, but on my previous car the brushes on the regulator got so low that it was barely contacting the alternator.

It could just be your battery man, is it maintenance free, or does it require distilled water? If so, what's the levels like? Should be 6 or so little screw-caps ontop, but knowing the R33's, you'll have to remove your strut brace and pull the whole battery out to check it.

[Mr Italy!]

Hey RANDY

I checked the battery yesterday and the fluid is fairly high under each of the caps...

I'm stumped.

[benl1981]

Mine did the same and was the battery. But check the voltage when the car is running - if it is 13.8-14.4v then the alternator is ok. If not you may havea shagged alternator and fixing battery wont help. 11.5v is too low. Mine is about 12.5v without the engine running.

Edited December 20, 2005 by benl1981

[RB30-POWER]

Well the answer is simple.

When this happened, did you have to jump the vehicle to get it started or did it just start after a few goes?

If you had to jump start the vehicle, it will be the battery being flat/discharged. And the clicking you hear is the pull in winding on the starter disconnecting because their is not enough current to hold it in, because the battery is flat.

If it started after a few goes, it may just be a sticky solonoid on the starter.

[RB30-POWER]

Reading surface voltage on batteries is next to useless. Unless you measure the voltage under a load you can't really tell shit.

[Mr Italy!]

Ahhh thats the ticket RB30-POWER!

I did have to jump start it.. so it is the battery after all.

So im assuming the problem with my battery due to its age is that it discharges very quickly, compaired to a new battery?

Or is the problem that under load, because of the degrading of the battery due to age, it doesnt have enough steady voltage flowing to the starter motor?

Yes.. you guessed it - i dont have a clue about batteries

[benl1981]

If it only has 11.6v surface it is fkd - no doubt about it. Surface charge cn tell you a bit as most god condition batteries will read above 12v. Although there is a chance a dodgy battery will read 12.5v but as RB30 said as soon as load goes on it drops away very quickly.

One you get the car started put the multimereacross the battery - if you get 13.8v your alternator is fine

[RB30-POWER]

Well now the problem lies.

You have to find out why it goes flat so quickly.

Is it just old and shagged?

Is there something draining the battery when the car is off?

Is the alternator charging the battery properly?

All easy to check if your in the know.

If the battery is a few years maybe just replace it and see how you go.

Otherwise.

If you think its not that old, go to an auto elec or battery place, get them to check for drains on the battery. (Just disconnect the earth cable, insert a multimeter set to Amps and measure drain)

And check if the alternator is charging properly.

(Alternator is easy to check really, check yourself, with the car on idle it should be between 13.6-14.7V with no loads turned on, like lights etc.)

Also they could load test the battery before you replace it, they will remove the filler caps and if a cell or cells bubble, it indicates a bad cell. That will cause poor performance from the battery. They will also measure the voltage whilst under a set load as well.

[Mr Italy!]

Yeah i see.

So if the battery is at 12.5V or 12V when you turn the car off, should it take a rather long time to have the battery then go down to 11.5V just by powering the head deck and speakers?

Like it takes mine about 10 - 15 minutes of playing before im stuck having to jump start the car... should it take longer then that to drain .5-1V?

Thanks guys.

Justin

EDIT:

Sorry i made this post just as you made yours RB30-POWER. I will take the car to a battery place tomorrow and have a chat to them and have them run a test or two.

I know its not the alternator because it does show 13.6+V as you said it should.

Thanks again for your advice!!

Edited December 20, 2005 by Mr Italy!

[benl1981]

Mine did the same as yours Justin. If you ran the radio for 20 mins you couldn't start it. Unless there is something draining it like an amp etc I'd say it may be just the battery.

Was a pain in the arse - was clutch starting for a while...

My new battery is fine Cna listen to the radio for an hour or so (with car off) - no issues

Edited December 20, 2005 by benl1981