battery drain

[michaelkowal]

i took the advice of the two guys show by disconnecting the neg cable to battery then hooking up a tester light from the neg cable to the battery terminal . then i went fuse by fuse to see if i could figure out which circuit was draining my battery and i got no results. none of the fuses made the lght go off when i pulled them.. My truck is a 1990 ford bronco full size with a 351w.
If anybody can help i would deeply appreciate it
thanks
mike

Everything is fused with the exception or your Alternator, Starter and Solenoid. I dont believe I have forgotten anything. Something has to be going to ground if the light stays lit. I usually use the positive post, but it doesnt matter.

[rapideo]

try removing wires from the alternator, a bad diode could be it

[michaelkowal]

Originally posted by rapideo
try removing wires from the alternator, a bad diode could be it

I took off the wires a couple minutes ago == still no
luck-- but thanks alot anyway

Do you have an aftermarket Ammeter? Also check your fusebox, Somebody may have added something to the unfused side if the fuse (wire for stereo etc.). Make sure you have no "extra" wires attached to your battery.

[justen]

things like car alarms and car stereo memory takes power at all times, but usually it's a very low power consumption, You might want to take the negative off your battery and see how many amps or volts it's actually drawing. You can do that with a multimeter. I know like for alarms and stereos or things like that usually pull between 1 to 2 volts per device. Also check little things like the hood light turns off. (The hood light usually uses a mercury switch.) and your glove box light turns off, could have a bad switch somewhere or a minor short.

[michaelkowal]

i wish it was only 1 or two volts - i am getting 12.5 volts -- just like i am checking the battery .. -- thanks again

[justen]

Well michaelkowal If your drawing that much volts it maybe a bad relay, Possibly the relay for your fuel pump or something in that effect. Might have a stuck relay, so check that too. Also could be in the ignition but things like that you never know, thats just a few more things you can look for.

What you meant to say justen was Amps, not volts. And what you mentioned would be measures in Milliamps and it would be a very small amount, say 100 to 250 mA. As the circuit, (any circuit) is in a 12 volt system everything in the circuit would draw 12 volts if on battery and more than 13 volts with the engine running and the alternator working.

The stereo memory, and any alarm system that was installed properly would be fused but not necessarily at the fuse box. Find all these fuses and pull them. Both of these constant circuits would take a month to drain a good battery.

Do the math. 600 CCA (per hour?) divided by 250 mA drain = a very long time. I once left my CB Radio on for 3 weeks while on the road and still had enough power to start the engine. Barely. I got lucky.

u could have also a bad batt, the batt will show 12v (internal short will show this) or 14.8v charging. but doesnt mean the batt is good. i had the same thing, went took the truck to autozone had them run a load test it was so-so. well started the truck it ran fine pulled the neg still ran untill i pulled pos it died (told me alt). i randomly had to get jump started. it was the alt that was bad, i got home and heard a whining noise and smelled like a burnt elec smell. it was the alt-took it in and 2-3v was all it was puttin out. luck i had both batt and alt in warr didnt cost a thing and never a problem since.