Kinda my week area, but why would car voltage show...like 11v, but voltmeter show 12.5 @battery

Were am I losing the voltage?
Car is a stubbon starter

 

is that 12.5v at the battery with engine off? 12.5 about right for just the battery,running should have ~13.5-14.5v at battery.The lower reading at the dash gauge could be the gauge reading a little low or some bad connections reducing the volts to the gauge some.

 

Yeah, thats with car off.
i cant for say for sure that the battery is good...maybe something wrong?

I check conectors,terms n grounds for battery, cleaned n re contected....just seems like car not getting all of the juice.... obviously...lol

 

Voltage drops as it goes through the car and connectors basically. Voltage at battery will be highest reading usually. And by stubborn starter, it spins slow? cranks for a few seconds or what?

 

Stubbon, by meaning

Starts when she wants not when I want.

Just sometime, first shot fire. Others it takes a while n sometimes nothing.


I took the battery out of my work truck stuck it in car, just to see.
It took a sec or two but fired over strong, and if anything, sremed likee car wasnt ready for thee battery, but when I put battery in truck again....truck took a sec to start.
Tested alt, n its charging

Worried I got a short.

 

If it cranks at normal speed , but doesn't start, its not a battery issue. If it turns over slower than normal, it may be.
If it is cranking slower than normal, make sure connections at battery, starter and ground (other end of negative cable) are clean and tight.

 

 

Thanks guys for the reply, i will test this as suggested to see what is the outcome.

Cranking, it is slower then normal (although the first inital 3secs) seem normal, i do have the 9th injector delete and was conserned that the fuel reg maybe a part to play, but i am at the time convinced its a power issue. the following few secs the lights will draw and the crank will go slower....

then as i said, battery will die.

if i leave battery hooked up for 3days with out running its dead, so i figured it was a draw

question is, still where? i did the fuse check although i didnt actually get anything on the voltmeter (test unit)

as for the car voltage gauge...yeah always shows lower then the voltmeter unit. and if its off, how do i correct? new sensor?

i am thinking of this...

new battery, with new cables (although mine look good), with a frame and block ground. not sure how the grounding could pull power out of the system (like draw) but at moment, i have a battery to block ground (i just cleans and remade) and the block to body ground behind motor...

question is? is it worth upgrading wire size to re do the ground and such?


just trying to make a game plan to really resolve this, but like i said i am not at all a wire guy and get lost in this aspect of the car, honestly. and am really not looking forward to buying a good battery and killing it cause of a draw or something small that i am missing....yet do i like chasing a ghost if it really is a bad battery...bad out the box.

what is the actual suggest crank amps?

 

battery should not go dead that quick, either a draw or bad battery, easiest way to test is to fully charge battery then let it sit for 8-12 hours unconnected, check voltage, should be 12.2 or higher >you can fudge a bit on the time. or take it somewhere to have it tested.
if battery tests good, have to move on to finding the draw, me or someone else will post more info later, I gotta run

 

I had a similar problem and it drove me nuts. I do remember fixing my alternator wire.Also, I disassembled the alarm and reinstalled all the wires correctly one at a time. That fixed some of my problem. Also, check to make sure that if you have a heated element window, that the connectors are connected in the rear windows. Sometimes, that drives my voltage meter crazy when one is off. And, make sure that the ground for the battery is in a good location and not connected with another ground for something else. Hope this helps...Tell me what you notice?

 

Ok so I am gonna get a new battery, probly time anyway.
Battery charged to 12.7 the night you posted n now is at 11.65...

But I do think I got a draw eitherway...

 

This is a good thought.
I have all door wires discinnected, due to lambo doors.
And the rear hatch motor n latch assembly disconnected. Door switches are also off, un pluged. Now thats what ive done...dont mean there isnt something somewere else.

The battery ground is going to block...i cleaned n re connected, didnt to look to have any corrosion, but I am tempted to move to frame n see if there is an improvement...

N yeah this is driving me nuts...i mean, believe me...i feel dumb asking, so ive checked n checked n checked all that I can think of...it just seems too fast or too big of a draw (if draw) to be 1 in a million....kinda figured it really be only 2or 3 things to create it n really exoected it to be in the network of battery to interior harness....but only cause of the gauge voltage....

Im hate to throw parts at this, but....i guesd replacing n maybe upgrading wires is the only way to know for sure.

Any body move grounds n find a better locationthen another?

 

Battery ground to block is fine, also need a ground from block to frame/body, that one doesn't have to be as big. Ground wiring is not causing the pull on the battery though. If your battery was getting pulled down, it will cause it to die pretty quick. Batteries don't like to sit discharged.
You need to use the ammeter function of a Volt ohm meter to find out whats causing the draw. Pull all the fuses, then disconnect the positive cable and put VOM in between, . If you have no draw on ammeter, put the fuses in one at a time till you find the circuit drawing current.

 

Got it, thatll be tonights mission

 

Ok, I am gonna test n post threw out the day, buy this is were I am now.
Battery 1 with 600 amps good, 12.2 not running.
Crank, no start just click.
Battery 2 with 650 amps good, 12.9 not running.
Crank, starts
14.48 v while running (headlights n blower on)
Car warms up, turn off....will not start second time.

so it seems the alt would be good, right

 

Ok


SO not to start a new threadill ask here first.

I got to the point of no draws shown on altmeter. Got new battery pluged in and alI went well.

Car did pull battery from 13 (at time of shut down to 12.7) in about 30mins
Ok seems like lot to me, but I never baby sat a battery so...I start checking again. It could be the charge dissipating but I notice a smal spark at pos terminal when connected....


So I pulled a fuse and checked again, sine metter isn't showing me anything.

Tail Fuse pulled....and no spark or crackle or anything.

I looked of wiring diagram. And searched to find ACC is also Tied in with Tail.

So question....heads are too....????
& what is actually on tail.
Hatch motor, light ect...or tailligh5s.

Only question is the headlight motors didn't spin with out the tail fuse and I was thinking tail ment hatch....not taillights

 

there is actually alot on the tail circuit, ive had so many issues with mine i had to run new to everything it powers because it melted the insulation off just about everywhere behind the dash. it goes to the headlight module as an off signal, plus all the lights in the interior(shifter,window buttons, gauges, etc.)

 

Lololololol...figures....
I don't realize it was that big of a circuit, but appreciate the reply. I think I'll attempt trying to find something on....like I said spark, so something is on when it shouldn't be.

If this fails in finding it...I will have to make that a project under my interior stage....see about replacing it.

But with your thought, IMA check back behind gauges first.

 

pull the plug with the white wire i think it is on the headlight module and try it then

 

OK, I'll make a note to do so thanks for the help