99 corolla VE ----Dead battery--WHY?

[99 corr]

MY 99 Corolla has had issues. I have had the joy of the DRL module buring out. Fixed that problem.

Now when the car sits for 24hrs the battery is dead!

I am a mechanic so not newbie at diagnostics but this car has me at the end of the rope!

I put a test light to check for the current draw on the ground cable of the battery. Test light lit up- have a draw somewhere.

Pulled all fuses one by one and could not get the testlight to go out!

Pulled all relays one by one could not get testlight to go out!

Pulled fuse/relay panel out (one under hood) and removed all connectors from it. Light goes out when I plugged in the connector that has an 8ga black wire and two white 8ga wires which I assume supplies the panel with power for the other circuits the light comes back on!

I check all grounds in the car except the end of the battery cable which is in the harness in the LF fender all tied up.

I even had all connectors un plugged from the inner fuse panel. Still had a draw somewhere.

Unplugged the alternator and power cable.
Unplugged radiator fan and ac fan.

I did find out that some how the engine is not grounded. I added a ground wire off the engine mount by the alternator and ran it right to the battery-.

Light went out!!

I hook everything back up thinking I have it fixed and still the battery goes dead.

I tried to jump start it with another car and the starter would just click like a dead battery.

Removed alternator and had it tested- OK.

Replaced starter yesterday and charged battery (battery is 3 weeks old).

Car started and ran like crap for about 45sec. then smoothed out and ran fine.


Here is my Question:

Will the ECM draw the battery down if the ECM goes bad?

Why the rough running at start up this time and then it evens out?
Never done that before.

I really need this car to run. I have very crappy schematics (chilton and haynes manuals) to go by. Have very little money to put into it being unemployed.

If any of you guys have had this happen and may possible know how to fix it or where I should look PLEASE Help! My kids will thank you!

[fishexpo101]

Sounds like you still have a bad chassis ground connection somewhere. The 1ZZ-FE is known to be picky about electrical noise.

As for something pulling down the battery that far - you are definitely looking for a short. You didn't mention the age of the battery - how old is it and what is the reserve capacity of the battery?

[99 corr]

I have removed and cleaned all paint from ground surfaces for all the grounds under the hood. Also done the same for the two grounds on RH & LH side under kick panels.

The battery is a new AC DELCO 550 CCA. 88RC

[fishexpo101]

Did you have a chance to throw a multimeter in there and check voltage levels from each of the chassis/engine ground points and see what kind of voltage you are getting. Probably close to source voltage, as you are getting that test light to come one, but getting actual voltage levels might be helpful. Same with current draws - wire an ammeter in there and see where most of the current if being pulled from. That way to can concentrate on that particular circuit "leg".

[99 corr]

I did get to do that and I was reading 7.86 v at the ground points on the engine cyl head, mount by the alternator, and on the main ground for the battery cable which goes to the tranny. There definitely is a short to ground but where that is I have no clue.

I have no resistance in my ground cables under the hood so I know the wires are good by testing, cleaned all grounds and reassembled.