Car trouble....electrical problem

[PrObLy]

Recently (first observed on Halloween) something has been draining my car's battery while it has been off much more than it should be.

Obviously, several things such as the clock/computer/anything 'hot' are expected to use a bit of juice but something has been sucking enough so I can't even get a good crank to start the engine.

I have eliminated the battery (pretty new, holds charge alone), alternator (>+14V when car is on), and starter (cranks no problem with juice) as being the problems...even though I will probably end up needing a new battery now after all these deep cycles.

I am not positive how much current is being drawn because I blew the fuse on my small multimeter (which will blow after 250-500mA). When I go pick up some more fuses, hopefully I can provide that number.

Anyways, I started pulling fuses to find out where the significant draw has been coming from. The culprit appears to be Maxifuse #10 60A located on the passenger side underhood electrical center.

According to the owner's manual this fuse controls the following: I/P Fuse Block, Courtesy Fuse, C/Ltr Fuse, Elec.Fuse, ACC Fuse

There's nothing plugged into the cigarette lighter and none of my interior lights have been left on nor are staying on..i.e trunk/glove box. I tried pulling all of the individual fuses in the main Fuse Block inside the glove box but could not identify the problem.

Also, I attempted to just pull this fuse (Maxifuse 10) when I turn my car off, but this results in tripping the damn reading lights and they won't go off.

Any help or suggestions would be greatly appreciated. I assume there's a short/bad ground somewhere or a relay is stuck on.

The car is a 1994 Buick Regal GS.

[mechmike0034]

Start here: http://flashoffroad.com/electrical/CurrentDrain/currentdrain.pdf

Also: http://www.cadillacfaq.com/faq/tsb/data/02-06-03-010a.pdf

Though the second link is from a Cadillac site, it applies to you as well.

[brainsmile]

I have a question car related.

My car when at a stand still and I start to accelerate has a moment where it's going about 10 mph and it starts to rev but the wheels don't have any power in the acceleration. It only lasts for a second or two and then it seems to go. No lurching or such but I'm wondering if it's transmission fluid or worse the transmission itself.

Also the check engine light just came on.

[mechmike0034]

I have a question car related.

My car when at a stand still and I start to accelerate has a moment where it's going about 10 mph and it starts to rev but the wheels don't have any power in the acceleration. It only lasts for a second or two and then it seems to go. No lurching or such but I'm wondering if it's transmission fluid or worse the transmission itself.

You mean the transmission slips? The engine revs up but the car doesn't move any faster for a second or two?


Also the check engine light just came on.

This may or may not be related and should be investigated.

Car year, make, model, engine size and manual or automatic transmission, please...

[johnnymk]

Start here: http://flashoffroad.com/electrical/CurrentDrain/currentdrain.pdf

That is a very interesting article. I didn't know that digital meters were unable to read milliamps accurately unless that shunt thing was performed.

How long did this car sit between starts? I have a hard time believing that a 6 or even 10 milliamps drain would affect starting unless it sat for a long time.

[PrObLy]

Start here: http://flashoffroad.com/electrical/CurrentDrain/currentdrain.pdf

Thanks a lot, MM. That will make things quite a bit easier than just doing the "spark" test :)






How long did this car sit between starts? I have a hard time believing that a 6 or even 10 milliamps drain would affect starting unless it sat for a long time.

You're right, and that's exactly what the problem is. There's a problem in one of the circuits that's causing it to take probably several hundred mA instead of a dozen or so.

As for the length of time it's been sitting, I haven't been able to really figure that out since the temperature around here has been changing so frequently, which really affects the battery. The first time it happened my car had been sitting for 5 days and the temperature had been in the 60's.
As the temperature has gone down I've had problems after it sits for about 3 days (from a 'full' charge).

The drain is so significant that running the car for ~30 minutes every day or so won't give it enough charge to consistently start every day now that it's cold out.

I'll report back if and when we figure it out...right now the hood is frozen shut so I have to get that open.

[brainsmile]

1995 Nissan Maxima GXE Automatic

[brainsmile]

I'm not sure if it slips, but it only happens when I accelerate slow. No lurching or jerking in any case. Just a pause sometimes.

Could it be the belts at all? It's got 140k and I don't think the belts have been changed.

[mechmike0034]

I'm not sure if it slips, but it only happens when I accelerate slow. No lurching or jerking in any case. Just a pause sometimes.

Could it be the belts at all? It's got 140k and I don't think the belts have been changed.

It is not the belts - without knowing more or being able to experience this "pause" there's not a lot else i can tell you.

[brainsmile]

This is what they said I had.

Front and rear O2 sensors out.
Knock sensor out.

[Daedalus]

Very plausible. Both will cause the car to run rich and give sluggish performance. Some info on the knock sensor:
http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/1f/4f/b5/0900823d801f4fb5.jsp
Ignore their test method; it's meaningless unless the sensor is open loop, which is almost never the case. If it was the check-engine light would have been on. The sensor usually just goes "deaf" over time. All 3 items are DIY jobs if you have the time and tools (aren't they all?). If the O2 sensors are original they may require a lot of physical encouragement to remove. You should pick up gains in perfomance and gas mileage once you get them done.