correct me if I'm wrong

[wutangwisdom]

so I tested my battery output with my multimeter today and it displayed 11.7 this is a bad thing right? I'm wondering if this is the stem of my rough spiratic rough idle.I'm  guessing the battery doesnt have enough juice to put the right output to all my sensors which may hinder their functions? The reason I check this in the first place was cause while my manche was running I turned the head lights on and it seems to idle rough for a second and then return to normal idle.

[Marine1Texas]

Your battery if drained or over heated can make low volts. Now when the engine is running it should be running off your alternator if it is good. When at idle alternator should be around 13 to 13.5 volts. As you speed up engine rpms to around 1100 to 1500 the volts can go up to 14 to 14.5 volts. If there is a drain on the system it can make the lights dim yes, like a bad battery taking up a lot of amps to recharge it. Now this is also a common problem with bad grounds. You need to check your ground and refresh them. If grounds are not got a good connection then charging will not be as good.

 

Check or refresh grounds, and clean contacts on head lights. after you can check your alternator volts and then battery.

Battery is only for starting and running things while engine is off. After started the alternator should take over and supply higher volts then the battery for engine and accessories.

[wutangwisdom]

Did all my grounds the first day i worked on it except the fuse panel ground and the fuel  pump ground, fuse panel will be next . I think my battery is a drain on the system at 11.7 it has had a terminal replaced by the previous owner and he said it took him 2 weeks to fix it.... I don't trust his work so its time for another battery.

[wutangwisdom]

Also I thought that the electrics ran off of the battery and the alternator was just there to keep the battery charged at the correct voltage

[Marine1Texas]

If that was the case the battery would not last long. If you notice in most cars if your head lights are on with out engine running the lights are dimmer. as you start it the get brighter. that is because of the volt increase.

 

Think of cars when they had hand crank, they had no battery, however had headlights and what not. The Generator of those days supplied the total electric. The way new cars work is almost the same. Other then not a dc generator.

 

Have you ever removed the battery while a car was running, it keeps running, unless alt is bad.

[Eagle]

Have you ever removed the battery while a car was running, it keeps running, unless alt is bad.

Thanks (NOT!) for reminding me about that.

 

A good many years ago I was building a Javelin to race in the New England hillclimb circuit. Trying to be as safe and (pseudo)professional as I could, I installed a kill switch on the transmission tunnel, where it would be in easy reach of my hand. Got it all wired in, fired up the engine to test it, hit the kill switch -- and the only thing that happened was the headlights got brighter.

 

After that, I had to sit down with the wiring diagrams and figure out where I needed to cut in my kill switch wiring to actually accomplish the purpose.

 

Embarrassing, to say the least.