Battery voltage/circuit question

[olds350]

I'm in the process of trying to chase down a possible parasitic voltage drain on my 08 bullitt. I recently replaced the head unit w/ one of the Raxiom units from AM. Also replaced the battery AND moved some after market gauges. I was going to used a mulitmeter on the battery and then start pulling fuses and watch for voltage drops.

So my question is....

If I hook up a volt meter in-between the negative cable and the negative post on the battery, should I see any values? Right now I'm seeing 12v on the meter. If I meter the battery itself, I'm seeing 12.7v.

Should I see voltage on a meter that's in-between the neg cable and neg battery post? Right now I can't see anything "on" in the car when I turn it off. The Raxiom unit beeps to verify turn off and all the gauges go to zero.

 

[s8v4o]

I'm in the process of trying to chase down a possible parasitic voltage drain on my 08 bullitt. I recently replaced the head unit w/ one of the Raxiom units from AM. Also replaced the battery AND moved some after market gauges. I was going to used a mulitmeter on the battery and then start pulling fuses and watch for voltage drops.

So my question is....

If I hook up a volt meter in-between the negative cable and the negative post on the battery, should I see any values? Right now I'm seeing 12v on the meter. If I meter the battery itself, I'm seeing 12.7v.

Should I see voltage on a meter that's in-between the neg cable and neg battery post? Right now I can't see anything "on" in the car when I turn it off. The Raxiom unit beeps to verify turn off and all the gauges go to zero.

When measuring from battery to battery cable you should be reading AMPS/Milliamps, not voltage. Measure amps and report back to us what the reading is.

 

[olds350]

I'll do that. Back later this evening....

 

[JeremyH]

Like mentioned you looking for current drops. Here is a decent vid on how to do it.

 

[olds350]

With my meter set on 10A reading, I'm seeing 0.36a worth of draw over the neg cable to neg bat post. I'm thinking that's pretty minimal on a car full of electronics. Just curious if anyone else has metered their current draw on the car when it's completely turned off.

Is a 0.36a draw normal?

 

[Pentalab]

With my meter set on 10A reading, I'm seeing 0.36a worth of draw over the neg cable to neg bat post. I'm thinking that's pretty minimal on a car full of electronics. Just curious if anyone else has metered their current draw on the car when it's completely turned off.

Is a 0.36a draw normal?

.36 x 12.5 vdc = 4.5 watts....which will suck a start battery down quickly.

On older cars, leave the dome light on.... and come back after the movie..to a dead battery.

I have not checked my 2010 to see what idle current draw is. For a more accurate reading, use a lower scale if you have one. If using a digital meter, like a fluke 87, etc, the polarity of the test leads is a non issue.

 

[HG6283]

With my meter set on 10A reading, I'm seeing 0.36a worth of draw over the neg cable to neg bat post. I'm thinking that's pretty minimal on a car full of electronics. Just curious if anyone else has metered their current draw on the car when it's completely turned off.

Is a 0.36a draw normal?

Start pulling fuses, one at a time, to see where the largest drain is.


.

 

[s8v4o]

With my meter set on 10A reading, I'm seeing 0.36a worth of draw over the neg cable to neg bat post. I'm thinking that's pretty minimal on a car full of electronics. Just curious if anyone else has metered their current draw on the car when it's completely turned off.

Is a 0.36a draw normal?

The industry standard is parasitic draw starts around 30-50 mA (0.030-0.050 amps). Yours is about 10 times that. As someone already mention pull the fuses ONE AT A TIME until you find out which circuit is causing the issue.

 

[olds350]

turns out fuse #56 for the radio is one of the culprits. Pulled the fuse and the amps went from 0.36 to 0.1. I can live w/ that. Now I just have to figure out what's grounding on the radio I just installed. Next week... too many other things to do right now...

 

[wabirch]

Shaker set up?

 

[olds350]

So I monkeyed around w/ the multimeter and fuses yesterday. I pulled the radio out to access the wiring and put the meter onto the neg post and neg cable. I watched the meter cycle through .7a and .3a in a pattern of 8 secs @ .7a and 4 secs @ .3a. This went on for about 15 minutes. I pulled every wire connection individually from the radio. What I found was when I pulled the largest factory connector, the amps dropped to .04a and stayed steady. When I hooked the connector back up, it started cycling again. Strangest thing I've ever seen.

I called AM and they said I needed to call manufacturer, Rosen. I told the Rosen tech what I was seeing and he said I had a bad unit. I called AM and a new unit is on the way. Now we wait....

 

[s8v4o]

Good, hopefully the new unit solves your problem. Nothing like troubleshooting something yourself!