negative battery cable carries current (hot)

[89daytonacs]

ok, i cant get my AEM UEGO wideband to work. so i decided to do major trouble shooting with my friends. heres what we found. gauge given power, and negative battery post touched as ground - gauge works. touch the negative cable to the post - gauge stops working. alot more crazy stuff aswell, but we concluded through theory and using a test light that the whole car is "hot" (put test light between negative terminal and negative cable and got power) therefore, i can't get a ground for the gauge (although other stuff works fine, and the car runs well ) anyways, my question is, what could cause this? are there any obvious and/or common causes? the alternator has been ruled out. thank you

also, if i start the car, take off the negative cable, and put the test light between the cabloe and the post, there is no charge

[HoverFish]

put test light between negative terminal and negative cable and got power

That's normal. You're completing the circuit.

[89daytonacs]

shouldn't the negative battery cable not be carrting a charge?

[Mopar318]

Make sure your connecting the right wires on the wideband. Theres a few that wont be used.

You will know if your car is not charging, or has wiring problems. Just this weekend, the wire going to the voltage regulator on the alternator fell off, and caused the alternator not to charge any more. My alarm started going off, my gauges needs were spinning out of control, and my displays where flashing random numbers. It was very odd.

[fishcleaner]

This is possible but not likely the cause. A dead battery can be charged backwards if you connect the charger up with the Pos clamp to the Neg battery post. I've seen it and the car ran, but had really weird electrical gremlins.

[Anonymous_User]

shouldn't the negative battery cable not be carrting a charge?

Once you disconnect the negative batter cable from the battery, you now have an open circuit. Remember, electricity wants to complete a circle. So, power leaves the battery on the positive cable, runs out through the fuse box, to the memory wire of your radio, to the chassis ground, and back to the negative cable you are holding in your hand. It can't go any further. Now, when you put a test light on the cable and the negative battery post, you complete the circuit through the test light. So, the test light comes on!




Disclaimer: Trying to make it as simple as possible without a discussion of electron flow and which direction the flow actually takes.

[Dusty_Duster]

That's normal. You're completing the circuit.

Once you disconnect the negative batter cable from the battery, you now have an open circuit. Remember, electricity wants to complete a circle. So, power leaves the battery on the positive cable, runs out through the fuse box, to the memory wire of your radio, to the chassis ground, and back to the negative cable you are holding in your hand. It can't go any further. Now, when you put a test light on the cable and the negative battery post, you complete the circuit through the test light. So, the test light comes on!
Disclaimer: Trying to make it as simple as possible without a discussion of electron flow and which direction the flow actually takes.

+2

This is normal.

Forget the wideband for a moment. Is your car running and charging correctly?

[89daytonacs]

that makes total sense now that i think about it. the car is definately runing well, and the battery charges well. any explanation as to why when i remove the negative cable and run the wideband's ground directly to the post the gauge will turn on (power is obviously connected also), and as soon as i touch the cable to the post the gauge goes off?

[Anonymous_User]

I would double check your power wire to the gauge.

Just like the test light, maybe you have the power wire to gauge grounded and when you remove the negative battery cable and connect the ground wire from the gauge to the negative battery terminal, it is completing the circuit.

[shelby zed]

its deffinately connected we put it right on the battery as well as the ground

[Anonymous_User]

its deffinately connected we put it right on the battery as well as the ground

So, you have the power wire for the gauge going directly to the positive battery post? And you have the ground wire for the gauge going directly to the negative battery post?

And you say the gauge works until you connect the negative battery cable to the battery.

Remove the gauge, connect the battery posts properly, and get a voltage reading across the battery.

[shelby zed]

yes, the guage works until the negative post is connected, but not if the positive is unhooked. will do next time i see paul

[89daytonacs]

got 12 V readings between the power and ground, but it still won't work. called tech support, and he figures that all i need hooked up is power and ground and itll work, so it should have nothing to do with the sensor end. put a narrowband back in and it worked right away using the wires i was trying to use for the wideband. (have tried to widebands btw, and two harnesses)

[89daytonacs]

had a mopar meet tonight. a couple of guys tinkered with it, one of them getting the gauge to light up, and go through its opening sequence by hooking up one of the datalog wires to the positive post. the gauge will not read correct readings when the ignition is on though, so this can't work. any ideas, crazy theories, random thoughts? anything will help. thanks

[89daytonacs]

people?

[shelby zed]

paul should update, he tried another guage and it worked

[89daytonacs]

paul should update, he tried another guage and it worked

meh, the thread was dead anyways