Battery Relocation

[Mike69]

Had my battery relocated to the rear on my fox body a few years ago and have had a issue since with it draining my battery. I basically have to disconnect the battery cables every time I park it. I rarely drive it though so never really tried tracking down the issue. I want to start driving it a little more now but need to fix this issue. As of right now it has a 1 gauge positive cable going from the battery all the way up to the solenoid and a 1 gauge negative grounded down to the frame.

I charged up the battery to 100%. Connected the positive side cable to the battery and left the negative cable unconnected. Took my volt meter and switched it to DC volts and connected the leads to the negative post and the negative cable and it read 13.45. Checked the voltage at the battery and it also read 13.45. Shouldn't it be 0 between the negative post and negative cable with the positive cable connected? The ignition switch is in the off position.

[Kart21]

At the risk of sounding stupid, what's left on in the car? Clock, dome light, radio light/ memory, elect. fan. How long before the battery is dead?

No shorts with the new wire?

It will read something if you have a draw on the battery, just keeping the ECU on is a draw if you still use that.

On mine a month w/o starting will need a touch up on the charger 'cause of the radio memory. How fresh is the battery, you have the right size wire but there is a large voltage drop when it's in the back.

Just my 2 cents.

[Mike69]

I can't think of anything that is left on the car. If I'm getting 13 volts between the negative terminal and the negative cable while the positive cable is attached to the battery doesn't that mean my negative side is hot? I tried the same thing on my truck and it shows 0 volts between the negative terminal and negative cable.

[Kart21]

Like I said, where is the completed circuit ? You are reading the return to the battery, the voltage you are reading is from what is drawing power.

The truck is completely off and you should not show any voltage back to the negative side of the battery. What it should be doing.

[garycrist]

A quick way to test with test light.

1. disconnect negative battery terminal.
2. insert test light between terminal and negative post on the battery.

If the test light lights, the drain is great enough to drain the battery.

Good luck

[black50]

I have a 78 mini cooper that did the same thing, just not near as bad as yours..

Start pulling fuses 1 by 1 and then measuring the voltage between the neg cable and neg post and you should be able to narrow down what is causing the drain

[Mike69]

A quick way to test with test light.

1. disconnect negative battery terminal.
2. insert test light between terminal and negative post on the battery.

If the test light lights, the drain is great enough to drain the battery.

Good luck

The test light did not light up at all. I'm wondering if it might be a bad diode in the alternator.

[SC457A]

Your getting feed back voltage from somewhere. Try just disconnecting the alt and retest, if no change would help you a lot to get a clamp on style amp meter and just start testing circuits.

Could use the fuse technique but really helps to have the amp meter while doing it also.

[Mike69]

I removed the alternator yesterday and took it in to have tested at 3 different auto part stores. At the advanced auto parts while the guy was trying to test it he kept getting an error about a bad ground on the harness connection. Manager tried it with the same result. He said he couldn't test it so I went to orileys and guy tested it there. While running the test the alternator froze the machine. Guy said it was a bad alternator. Couldn't test it anymore. I then went to auto zone. While trying to test it the machine kept on getting an error on the harness connection. Guy tried several times and couldn't get it to test. I ran out of time and didn't have the opportunity to take it to a few more places to have tested. Is it possible that the alternator is bad somehow and not allowing the machines to do a good test on it?

[4bangen]

seems like it's time for a new alt.

[Mike69]

Couple of things I noticed when they did the 3g alternator upgrade is that the two 10 gauge power wires are still being used and No 4 gauge power wire is used. From what I've read, the two 10 gauge wires should not be connected to the alternator and to use a 4 gauge power wire with a inline fuse from the alternator to the solenoid. I also didn't see a ground from the engine block to the frame.

[Mike69]

Little update: I replaced the 3g alternator, ran a 4 gauge power wire with inline fuse instead of the original 10 gauge wires and added a 4 gauge ground from the engine block to the frame. Seems to be holding a better charge now. Haven't driven it since Friday so I'll take it out for a drive today and see how it's doing.

[4EyedTurd]

I was gonna suggest when you take it to get tested and they have issues, see what a brand new one does on the tester. That would tell you if it's operator error, alternator or machine.