I pulled each fuse and did not find source of one amp parasitic loss which kills battery in 2 days---any suggestions????

 

1 amp over 2 days would be around half the battery's capacity, are you sure it's not the battery that is at fault.

 

bbaum,

If you really pulled every single fuse (there are a number of fuse boxes!) then that might imply its the battery or connections.

However, if you haven't actually pulled all teh fuses then the notorious areas that I would look at are:

- Boot light - very common that the switch on the boot isn't performing properly. Put a mobile phone on video record in the boot, shut it and check.

- Security system. Another common current draw

- Radio aerial circuit. A failure in the aerial can cause constant draw

- Ventilation system fans - but usually accompanied by constant running of one or both fans

Good luck

Paul

 

I had the same issue with my 93 XJS coupe. It wasn't the trunk lights, the radio antenna, radio, nor security system. It was the alternator. You have an on board computer system that can diagnosis the electrical grid. Go to Auto Zone, O'Reilly's and get them to conduct the test for you.

 

After following your suggestions ;the problem was in fact the radio aerial.after pulling it's fuse the loss went down to .06 amps.

 

That's more like it, glad you found the problem all you have to do now is resolve it.

 

I've been wondering about this. What is the normal battery draw with everything off? I think I measured mine at about .7 amps. I don't know if thats normal or not. My battery will not start the car after about 4 weeks of sitting depending on temperature. Btw my security system is sitting on the work bench.

 

Glad it is solved!!


An isolation systematic process is:


1. disconnect the battery. Measure the volts. Let tit rest a day or two.
Measure again. If no significant drop, it is fine and the car has a close circuit that should be open!


2. All circuits open doors included. Disconnect battery - cable. Read amps to ground. .045 OK. If significantly more, a circuit is closed that should be open. Boot light?


Carl

 

Two after thoughts here.
First, in reviewing parasitic consumption a few times in the past, I've determined that the closest to "normal" that I have seen after issues have been resolved was always around the 40 to 45 ma. Anything above this you need to start some diagnosing because it is above normal, even with fancy stereo equipment, that is from past experiences.

Second is that, for peace of mind, place a digital volt meter in the cigar lighter receptacle, making sure it has enough resolution to indicate at least one decimal point. They come with the integral cigar lighter male and they cost peanuts, like $5.00 from eBay or Amazon. As long as you know correct values, you'll always know where you are, only thing is that, in order to have this little gadget, your cigar lighter receptacle needs to be changed to hot all the time, which is what I did, otherwise you can only read the gauge with ignition ON and that is no longer battery at rest. I have done this to all my three cars and, as long as you know what the voltage should be with ignition OFF and ignition ON, you will know where you're standing. You get used to the readings and will immediately spot when something weird is going on. There's another unit you can buy that adds a green, amber and red LED's to rate your charging conditions. That one is only for wealthy individuals: $10.00.

Cheers,