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Battery Drain 96 Ledorado 4.6

I have a 25Amp drain ( 300Watts divided by 12Volts), on my battery. I think it should only be about 6 Amps. So, what could be taking Aprox. 300 watts? I’VE checked to see if any lights or heated windshield were on, but all seem OK. Am I missing anything? What do you suggest? Please

When are your measuring this?  Is the engine running, is the ignition on etc.  How are you measuring it?

the additional drain is 19 amps. Why do you keep quoting watts? Current drains are usually listed in amps. How are you getting this measurement?

Afer not using my car for 3 or 4 days, I was finding my battery was dead, so I took my car to Advanced Auto Parts to have the battery checked. They tested my battery and said it and my alternater were OK, but I had a large drain of 25 Amps. I took my car home and did the test myself as follows. With the engine and key off, I disconnected the Neg. battery terminal cable. I attached one end of my multi meter, which I set to the amps scale and the other end to the cable end and found the results to be the same. I also notced that there was a considerable spark as I re-attached the cable, which I concluded was the resutl of a larger than normal drain. Assuming all the facts are correct, what can you make of this.

I believe that some cars have an initial drain higher than normal. That is when you disconnected the battery cable and reconnected it though your meter you may have been measuring some temporary current that in five or ten minutes later may have disappeared. In addition I have heard of some cars that have a higher then normal drain for some minutes after it is turned off.

Anti-theft devices are often the source of some un-expected power use with key off.

Sorry I can’t offer anything more specific.

A 25 amp discharge is huge. Enormous! Normal values for cars used to be less than 200 ma (a fifth of an amp!) but the recent addition of so many passive monitoring devices, such as antitheft and GPS gadgets, have doubled and tripled this value. But 25 amps! I don’t believe it. That will drain a car’s battery completely in less than an hour.

“Am I missing anything?”

Suppose you go back to the beginning and tell us what your car is doing or not doing.

Are you sure you are reading your meter correctly? I’m surprised that fuses aren’t blowing.

The battery drain spec for this car is 30 milliamps. In fact you need to see the procedure for checking a battery drain, it is quite extensive. You can’t just unhook a cable, install your meter and read the drain. The system needs to power up for at least 20 minutes before any readings are taken. Even then there are modules that wake up and perform tasks that can mess up your readings.

Like SteveF stated, that amount of current draw is huge. Even if the systems are not in the sleep mode you shouldn’t see that high of draw. Something is seriously wrong and it shouldn’t be too hard to find since you have a meter to check with and know how to use it.

Things that draw a large amount of current are seat heaters, window defrosters, and various motors. By pulling fuses one at a time and monitoring the current, you should be able to find the area of trouble pretty quickly that is drawing the extra current. You need to keep in mind that there will normally be a fair amount current draw before things go into the sleep mode. I would guess that 3 to 6 amps may be about right but don’t know for sure. You might check the alternator also if you have trouble finding the trouble area by using the fuse pulling trick. The blocking diode in the alternator may be bad and cause this trouble. Be careful if you work with the alternator output lead, it is hot to the battery and you will cause a big short if you touch that lead to ground. It is best to disconnect the battery before working on it. There may also be something in the engine compartment area that has failed or has a low resistance path to ground somehow.

With the very high extra current draw it seems something should be heating up and easy to locate.

I also have trouble believing it’s a full 25A, that would be a huge drain and would quickly kill the battery (in hours, not days). Are you sure you have the units correct?

There are fused circuits off the battery, or power distribution center, and there are unfused circuits. Look at your wiring diagrams. The wires going to the starter and to the alternator are unfused.
Pull all the fuses and check for current. If you have current, disconnect the cable to the starter and the large (10, or 12, or 14 gauge) wire to the alternator. Check the current draw.

I figure that a Ledorado is a motor home. I also figure that there is a short circuit somewhere. A wire is probably chafing on metal somewhere. I usually find this kind of thing on an add-on circuit that was installed by people who weren’t too careful. Anybody qualifies as “not too”. Under the vehicle is where some of the shorts happen.