Jump to content
SAU Community

Voltmeter goes past 15volts?? Battery overcharging?

AeroGrace

By AeroGrace,
in General Maintenance

 Share

Recommended Posts

AeroGrace Rising Star

AeroGrace

Posted
Posted

On my dad's gtst, we have a turbo-timer that has an inbuilt volt-meter that is preset to warn in below 11volts or over 15 volts.

then recently on starting up, the volt indicator would go up to very high limits of 14volts.....any press on the throttle would result it going up even further up into the 15 volt limit.

And it'll just stay around 15.2-15.7volts throughout the trip. Is the batterty overcharging for some reason? Or is the alternator rooted? All other instruments seem to work fine...although the only other thing i noticed was the headlights sometime seem to flicker slightly on startup.

Hope i made sense. Anybody has experienced this?

thanks:)

JimX Grand Master

JimX

Posted
Posted

Yeah first thing to do is test it in your driveway (revving engine) with an accurate multimeter. If the voltage is definitely over 14.5V or so then get the regulator fixed asap! Seriously, you will start to blow your car's electronic stuff up if you let it stay over 15V. I know someone who had an old Magna that was running on about 16V and one by one his gauges started dying, and then his CD player.

A new regulator should be around $100 or so. A nice auto electrician will replace it for you for free (should be a 5 minute job).

camandcandice Collaborator

camandcandice

Posted
Posted

hey i had this problem couple of months ago. Check your fuses in the boot, i had been playing around with those fuses and put one back in the wrong place causing my battery to overcharge like you have described.

camandcandice Collaborator

camandcandice

Posted
Posted

check your fuses first dude it will save you money. As the ALT-S fuse often blows. The ALT-S fuse controls the alternator telling it when to charge the battery and at what volt, when this fuse blows or incorrectly placed the alternator continuously charges the battery flat out, compare the fuse layout to the cover

wrxhoon Grand Master

wrxhoon

Posted
Posted

the voltage reg is built in the alternator , an auto electrician will usualy sell u a reco alternator regardles were u have a crook reg or alt . the diodes in the alt maybe the prob or volt reg .

go to an auto electrician and he will check it for u , u may have a crook multimeter , one way to find out check the voltage on the battery engine not running then check again engine running notice the diff it should be 1/2 to 1 volt if battery is fully charged

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • GTSBoy
      Boost cut after swap(RB25DET NEO) R34

      By GTSBoy · Posted

      Don't even try to run it on the stock ECU if you're going to have the boost controller bring boost above ~10 psi. I've already told you that. If you use the Nistune ECU, you will need to CAREFULLY read the available documentation for Neo tuning, and read some threads on the Nistune forums, to discover the various things you have to do to prevent the ECU from going bananas when the boost is too high. The is a table associated with th boost sensor that must be modified to prevent it from shitting the bed. This is just one of the things that you will need to do to the tune in Nistune, because the Neo turbo ECU will be expecting to see a number of things (such as the TCS) that are not there, and you have to block the DTCs on those. It is totally not surprising to me that you are having the problems that you are, but the solutions to these problems have been known for >15 years. So just get it done.
    • dyl33
      VOLK RACING GTC CENTRE CAPS

      By dyl33 · Posted

      Centre caps $250
    • Kapr
      Boost cut after swap(RB25DET NEO) R34

      By Kapr · Posted

      Hi. Sry iam not a mechanic and iam not at the car atm so i dont know 100% but they told they measure those and even try to change those. AFM they have two. Coils are new a they have my old one too. Plugs too. ECU...we have 25 NEO stock and Nistune 25 NEO.   But i dont know if any one those could be the problem and why/if/what can cause this, Only thing they did not check is fuel...but that walbro 255 is new(like 1,5 years)... That fuel pressure gauge idk...but i let them know Any suggestions?   EDIT: how can they know if it is like you say he ECU pull power when it reaches a specific boost level that is too high? Tha car has boost controler
    • Duncan
      Boost cut after swap(RB25DET NEO) R34

      By Duncan · Posted

      Can you clarify what you mean by boost cut, do you mean it misfires both when under load (driving) and when stationary and out of gear? Or does the ECU pull power when it reaches a specific boost level that is too high (boost control issue)? Does it occur at idle with no throttle? When you say "the ECU is OK", what ECU is it and why do you think it is OK? Have you used the NEO ECU, and if so do you have a MAP sensor attached? Same for the AFM, why do you think it is OK? Do you have any way to put a fuel pressure gauge on it (even just a mechanical one between the fuel filter and fuel rail)?
    • Kapr
      Boost cut after swap(RB25DET NEO) R34

      By Kapr · Posted

      Hi.. Just another problem. So maybe you can help. I(my mechanic) done swap from my RB20DE NEO to RB25DET NEO. Everything is OK but we have a boost cut. Coils/Plugs are ok...AFM is ok. ECU is ok. I have Walbro 255 but it "changed" sound few months ago(you can hear it ouside) you did not hear that when it was new(maybe faulty?) Sooo...what now? What can cause this boost cut? It is even when you standing still...
×
×
  • Create New...