Car Dead....driving me crazy!!!

Hopefully I can fully explain what's happening. When I bought my 93 Metro xfi 3 months ago it had a new battery.

About 2 weeks ago I let the car sit for 4 days in 0 degree weather and the battery was dead. So I pulled the new battery I bought in June from my Mustang into the Metro and was good to go until I let it sit for another 4 days.

I immediately threw the charger on it in the morning and when I got home tried to start the car and nothing. So I had the alternator tested at Autozone and they said the diodes were shot. Bought a new one for 125.00

Got home and installed it and checked to see if the battery would start the car and still dead after another day on the charger.

The way I understood the guy on the diodes going bad is that sometimes it will charge the battery sometimes it won't.

Now if I drained two new batteries and let them sit for 4 days, did I trash the batteries or is my problem elsewhere?

Off the charger the batteries show 10.00--10.68 volts, on the charger they show between 8 and 9.

Yikes, something is wrong here. Take these voltages and advise what you get. Remove the charger. Remove the negative (ground) clamp from the battery. What is the voltage across positive and negative of the battery? Connect the voltmeter to the negative terminal of battery and the other voltmeter lead to the negative cable you have have removed. What is this voltage? Connect the charger to the battery, leaving the negative clamp off. What is the voltage across the postive to negative?

Ok. This is what I found::

Removed charger. Disconnected Negative on Battery. Battery output is 10.46 volts

Negative Battery post to negative cable is 8.76 volts.

Connected charger left - off and tested + and - got 10.51 volts

Don't know if this helps but I installed a radio 2 days before this started happening.

I pulled the fuse from the radio.

Amps w/ fuse (neg to neg) 8.76

Amps w/out fuse (neg to neg) 6.71

Reinstalled negative cable and battery shows 8.71

Here is a link to online videos which include testing the battery etc...The videos start off basic then go into a little more detail. Hope this helps

http://www.expertvillage.com/video/20311_car-battery-change-dead.htm

Looks to me like you have a couple problems. First, the voltage put out by the charger should have been about 14 volts. Since it stayed the same with or without the charger, I'd say you have a problem with the charger.

With everything off in the car (even the dome light) and no shorts, the voltage between negative terminal and a disconnected cable should be near zero. Start pulling fuses and note the voltage and what fuse was pulled. When you get a large reduction in the voltage reading, this is the circuit that either has something on, or a short in it.

Update..

Replaced my battery (free replacement) and hooked it up. 12.49 volts with the car off.

Started car battery jumps to 14.71 volts so I know my new alternator is working.

Disconnected the negative terminal (figured out how to use my multimeter) and with the stereo fuse in it was drawing .51 amps.

Took out the fuse and its drawing 0.00. Problem found.

Next is figuring out how to trace the stereo wire down and find the short. Autozone probably has a tool to help with this.
Whatever I figure out I'll fill everyone in.

Have some probing to do this weekend. Wasn't paying attention earlier when messing with the car but when I reconnect the neg. cable on the battery the door makes a very audible click sound on the drivers door.

It's on the same fuse as the radio and the sound comes the seatbelt retractor area. Door lock never moves. I'm wondering if when I replaced the door handle I damaged something.

I'll take off the door panel and disconnect the seatbelt solenoid and see if that cures the drain.

Atleast internet says .51 amps with key off is too much drain.

Does your dome light work? Door switches are famous for failing.

Woodie,
The dome light does work. And I assume by door switch your talking inside the door not the switch that's on the rocker panel.

I hope I can get to it this weekend and find my problem. I might unbolt the fuse panel and start probing to help find my short.

Problem fixed!!!!!!!!! Finally. :grinyes:

Tore off the door panel and had the wife listen to where that load clicking sound was coming from when I'd connect the negative battery cable.

She said the seat belt was moving. So she worked the battery while I watched and sure enough it was. I unplugged the to connectors going to it and checked my amp drain.

Went from .51 down to .09!! Definitely within specs to keep my battery fresh.

Thanks for all the help and imput. Everything I learned was off of this site. Do a search or ask and there's your answer!