: Battery drain

07-29-10, 08:19 PM
94 Eldorado 4.6 Northstar Engine 77,500 miles. I installed a new alternator because of alternator noise which turned out to be diodes, ohm meter showed A/C voltage ripple going into battery with engine running. Have not started car since installing new alternator, concern about damaging new alternator. The existing battery is 12 months old, fully charged & holds a charge when not hooked up. Hooked up 12volt test light attached test light clip to ground side of battery and connected probe to the negative ground cable which is removed from the battery. The test light came on, I pulled all fuses (regular fuse blocks & MAXI fuse block)one at a time both in engine compartment & trunk put each one back after testing each fuse. Test light still on after checking all of the fuses. YIKES!!! Pulled A/C comp, horn, fuel, & headlamp relays one at a time & put them back after checking the test light, test light still stays on. All battery cable connections are all nice and clean with no corrosion. I had the new alternator checked at the parts store before I paid for it, it passed the test. I have both + & - battery cables disconnected right now and have taken my ohm meter and connected each corresponding lead to each of the disconnected battery cables, it read between zero (0) and one (1) ohm. If I don't know what circuit the problem is located in because the fuse & test light didn't give any clue, what next.