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Billpro785 04-05-2011 09:32 PM

correct voltage ??
 
Have a dumb question , what should the voltage be on a NAF kit car ? Reason I ask , The gas , volt gauges are inop , headlights dim, with a volt meter get 13 at the battery , but on 7 volts at the fuse panel . Bad ground ? Or is there a voltage regulator somewhere ( like the Chryslers had behind the dash ),
Thanks for any ideas

Rick Parker 04-05-2011 10:40 PM

12 volt throughout

lnfletcher 04-06-2011 07:15 AM

When you check the fuse panel and get 7v, where are you getting your reference ground?
If at the battery, then you have a bad connection to the fuse block, if elsewhere, it could be a bad ground or bad connection to the fuse panel.
Check with reference to battery ground and you eliminate one half of the question.
Check the actual connection on the battery positive to main cable connections for obvious problems.
Hope this helps.

mreid 04-06-2011 07:20 AM

You will usually see around 12.8v out of a fully charged battery and that should be the same at any point in the system and around 14.2v when the engine is running and the alternator is charging the battery.

You've got a wiring issue, but I don't think it is ground related. Assuming you've already conducted a visual check, you can check it by disconnecting your positive battery cable and then checking continuity (resistance) using an ohmeter (multimeter) set on r x 1 between the negative battery terminal and as many of your ground connections as possible. Once you rule this out, use the ohmeter to check from the positive cable to the fuse box battery strip, then turn your key to "on" and check to the ignition strip. If all of that is good, it is time to check from each fuse to it's circuit. Time consuming, but it is the only way you will find a potential broken wire, miswired circuit, or pinched wire. Good luck!

Ron61 04-06-2011 07:44 AM

Quote:

Originally Posted by mreid (Post 1121042)
You will usually see around 12.8v out of a fully charged battery and that should be the same at any point in the system and around 14.2v when the engine is running and the alternator is charging the battery.

You've got a wiring issue, but I don't think it is ground related. Assuming you've already conducted a visual check, you can check it by disconnecting your positive battery cable and then checking continuity (resistance) using an ohmeter (multimeter) set on r x 1 between the negative battery terminal and as many of your ground connections as possible. Once you rule this out, use the ohmeter to check from the positive cable to the fuse box battery strip, then turn your key to "on" and check to the ignition strip. If all of that is good, it is time to check from each fuse to it's circuit. Time consuming, but it is the only way you will find a potential broken wire, miswired circuit, or pinched wire. Good luck!

That is a very good answer and while checking your grounds, be sure to check that they are making good contact and have no paint or rust where they are attached. Also if it takes longer than you expect, don't give up. You may be lucky and find it right away or it may take hours or even a day or so to track it down.

Ron :)

Billpro785 04-06-2011 07:46 PM

Thanks for all the help, Spent the day checking grounds, pinched wire , etc,
The builder of the car did a great job with the wiring , So I sure it must be something simple .
Will dig more into tomorrow

Blas 04-06-2011 08:04 PM

Not following all that was written, and not knowledgable with NAF cars, but where is the "+" power feed to the fuse panel (and then on to the rest of the car) originating from? Where is the battery located? Is there a master fuse? If there is a main power feed post on the fuse panel, consider disconnecting the current feed line and running a temporary new power feed line and see if that helps. Minimal cost. It should be a good size wire too. Any heating on the original main feed wire when in use? Your main power is not routed thru the ignition switch is it? If I had a wiring diagram it would be helpful to me...Anyone?

Billpro785 04-11-2011 12:15 AM

Well to let all know who helped me, found the issue , The main cable (neg.) from the battery to the frame was bad , the cable inside the plastic cut in half ( factory defect ? ) Looked ok from the outside .
Thanks everyone for their help !!

PANAVIA 04-11-2011 01:30 AM

NAF or not does not matter, -- auto electrics is -- auto electrics.

My personal rule of thumb is when a car is not running -- 12.3V measured at the battery terminals --

when a car is running , with all accessories on ( lights , fans, AC , engine ) i like to see 13.9v, but can live with 13.4v.

--steve

John S Peterson 04-11-2011 02:57 AM

Open circuit voltage of a battery should be 21.6V, as there are 6 cells each at 2.1V. Charging voltages vary based on resistances in the system including the battery itself. Battery temp plays a big roll in charging, as it is harder to charge a cold one rather than a hot one, % of battery charge is also a factor for output voltage, AC ripple is another, but your biggest enemy is voltage drops. This is stuff that I do and it would be fun to do a basic electrical workshop giving the steps necessary to interested parties making it easier to solve electrical issues with more confidence.

John Peterson

392cobra 04-11-2011 06:04 AM

Quote:

Originally Posted by John S Peterson (Post 1122069)
Open circuit voltage of a battery should be 21.6V, as there are 6 cells each at 2.1V.
John Peterson

No doubt a typo,should be 12.6V.

John S Peterson 04-11-2011 04:51 PM

Big typo at that.........thanks

jp


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