Odd voltage.. why...?

[Ali1 10+ year member]

Does the yellowtop drop or does it stay at 12.5?

never checked voltage drops at the yellowtop.....

 

[Johnny Drama 5,000+ posts]

never checked voltage drops at the yellowtop.....

Stop posting...get your *** outside and check your fuses.

 

[killahbean 10+ year member]

Stop posting...get your *** outside and check your fuses.

LoL....x2

 

[Ali1 10+ year member]

lol... ok here's a few pics i just did with voltage... to show where i stay at... and apic of the fuse. hard to see,but it's relatively new....

 

[theCybe 5,000+ posts]

DMM on ONE end of the wire leading to the fuse

and DMM on the OTHER end of the fuse

THAT is what they've been trying to get you to do.

Do it.

 

[theCybe 5,000+ posts]

If you have a higher reading BEFORE the fuse than AFTER,

the FUSE is the PROBLEM. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Ali1 10+ year member]

ok, did some more testing. i get 13.8 right before the fuse. I get 13.32v after the fuse. am i supposed to be losing any volts?

I didn't know the amp takes so much juice from the battery just to turn on. yellowtop is @ 13.32v before i turn on my amp, 12.6 while the amp is on. Is this normal to take out this much? I also get voltage drops from the yellowtop while the system is running....grounding point is @ .03ohms.......

 

[Ali1 10+ year member]

ttt

 

[helotaxi 5,000+ posts]

ok, did some more testing. i get 13.8 right before the fuse. I get 13.32v after the fuse. am i supposed to be losing any volts?

No. You shouldn't get measurable drop at all. Either the fuse is bad (doubtful ut possible) or the connection between the holder and the fuse is bad.

I didn't know the amp takes so much juice from the battery just to turn on. yellowtop is @ 13.32v before i turn on my amp, 12.6 while the amp is on. Is this normal to take out this much?

The idle current of the amp is probably around 5 amps.

I also get voltage drops from the yellowtop while the system is running....grounding point is @ .03ohms.......

If you can measure the resistance between the negative battery terminal up front and the ground point, you have a terrible ground and that is your problem. Voltage only drops when current is drawn. The voltage drop is proportional to the resistance of the current path and the current drawn. Fix your ground. Just because you have the neg wire run to a point of bare sanded metal you don't automatically have a good ground. The chassis of the car is probably not providing a good return path and is causing the resistance leading to your voltage drops. I would consider running a 1/0 ground cable back to the red top from the yellow top and grounding the amp to the yellow top.

BTW, the pos wire between the red top and yellow top should be fused twice, within 18" of each battery.

 

[Ali1 10+ year member]

so if both of my grounding points show .03 ohms bare metal, are they considered good grounds?

I will chek one more time about my wiring, but i checked it thoroughly before i even made this thread.....

What are signs of a bad battery? I am beginning to think my yellowtop is going bad?

So then, something is wrong with the ANL fuse if the above information about the voltage loss is true, right? Or is it the whole fuse holder?

About running a second run of 1/0 to my negative posts, i will do that sometime down the road. I don't have any wire left around except for a few 1ft. pieces.