60mA is not too bad, a 100Ah battery should last about 70days.

How is your charging voltage?

Also check the boot lights, I mean get in the boot and close the lid. I chased a battery drain for hours and it ended up being the boot lights not turning out when the lid closed. You will not find this by closing the switch with your finger as I did.

 

Thanks for the reply!
I tried leaving my phone recording in the trunk and the lights went and stayed of ...., but it does seem like I have to slam the trunk for the lock to engage...which is what cuts the lights out. So maybe it is that after all......I am glad that there seems to be no drain from my aftermarket fans or alpine stereo, but there I something definately draining my batteries.

 

Mark, as you mentioned in post 13 the door cards had been removed. Perhaps that is the place to start looking.

27 milliamperes is roughly where it should be for a healthy system and the spike you have seen is nothing to worry about.

Did you have the problem prior to the door cards coming off?

Can't remember if the XJS has the flap in the ignition switch but worth checking also that any auto functions are switched off.

 

Hi mark, firstly I would think you have connected correctly . the MM seems to be on Amps and reading to 3 decimal points meaning that you have a reading of 27 to 61 milliamp's (ma) ? .If that is the case you can now turn the MM to the ma position , if your MM has more than one ma selection go down until you have reading of 2 digits before the decimal point....TO be continued

 

If the reading is what I believe it to be it is in the normal range and does not indicate a parasite , unless it is intermittent !!.As it stands and by way of explanation , what we are interested in is amp Hours (AH) to show how long it would take for the battery to go flat at this rate.
Auto starting battery's are usually not rated in AH but cold cranking amps (CCA ) and reserve capacity (RC) a simple way to get close to AH is the following formula.


RC divided by 2 + 16 = AH
To be continued ( sorry IP problems .

 

I will assume you have a battery in the 650 CCA and around 96 minutes RC so you would have the following :-
96 divided by 2 = 48


48 +16 = 64 AH
Because we have an ma reading we will go to ma so we have 64,000 ma
We will use 50 ma as your average battery loss as your flashing light is off more than on and I think that is generous which would mean that it would take :-
64000 ma divided by 50 ma = 1280 AH = 53 days <> to go flat.
Sorry that this so long winded but this may help someone else one day if they need to work what setting to put there MM on , or to work out how long an appliance will run on 12VDC.
So moving along you can check to see if your alternator is charging to spec , start engine MM on VDC , pos MM to Pos battery , neg to neg.If it is in range that is a good sign but it is possible that the amperage is too low and not charging the battery , you can NOT use your meter to test for alternator amps and unfortunately a trip the auto electrician will be necessary unless you have a meter available to yo that can read in excess of 75 amps , it may be just the regulator !! whew got there .

 

Thanks everyone for your responses.

Well I left the car sit for four days and she started right up.

Only thing I did differently is I have been slamming the trunk shut a little harder, and I unplugged the battery for those tests, so either it was the trunk light not shutting down, or whatever was continously drawing electricity stopped or reset itself by disconnecting the battery.

 

I divined a boot lamp test. I've not needed it, so far.


Tool needed.


Boot lamp, dead Ok, will be damaged. Household door bell. Wire and solder tools and skills.


Break the bulb glass. Solder red wire to the inner filament stem. Solder black wire to brass remaining case. Solder or connect red and black to door bell.


Plug altered bulb base into receptacle. key on, boot open, it should buzz....l Close boot, buzz should stop. If not, that is the parasitic drain.


Now, the fixes.


1. Leave the bulb out. How often if ever does one need to see in the boot at night?


2. Adjust the linkage.


I think mine does not work,. but so what, there is flash light (torch)there.


Carl

 

Hello Gents-

bringing back this topic I created 3 years ago. Basically I never really solved the problem to my satisfaction, and I always maintain the battery disconnected to prevent it from going flat if I know I won’t be using the car for a while........ Mechanic at that time wasn’t able to find anything either at that time but the battery did eventually go flat again after the car remaining un-driven for a while.... Last week I once again did test with the multimeter and it yielded exactly the same results as 3 years ago......no drain. I would like to resume leaving the battery connected in my XJS as it is ridiculous to have pull everything apart to reconnect , and also to reset clock and radio.

Is there something else that could have been intermittently draining my battery that I missed? As was discussed originally, trunk lights come of, interior lights come of and I still do not see a drain with the multimeter, it still goes between 30 and 60 as the keyless entry led by the lighter lights up exactly as in the original video I uploaded here in 2016

 

The power antenna is a known issue on these cars. I would suggest pulling the antenna fuse to see if that has an effect.

 

the antenna has been disconnected for a while.... I am looking for a replacement.

I went ahead and plugged in my battery and see what happens. Rain is in the forecast until next week so I won’t be driving her. We will see if the battery goes flat

 

Curious to follow this thread as I am having same problem in my 1994 Coupe! New batteries don't fix it. I plan on sitting in my garage by myself tonight in the dark and screwing with it!
Thanks!

 

Have you hooked up the multimeter too? ....

three years apart and mine still reads no drain when tested. I am thinking part of my problem is that my last employer was quite literally a mile away from home. The battery never had a chance to recharge at all. All I know is that there is no drain from anything I can find and all lights, including trunk, turn of as intended

 

Spikepaga,

Question #1: I'm sure it's a yes, but do all of your cabin lights work? Just making sure that a faulty light that isn't visible isn't at fault.

Question #2: Have you considered pulling the fuse on the security system? That seems like the next likely culprit.

Question #3: The next suspect is the radio. After discovering that the power will still drain out after pulling the fuse for the security system, replace that fuse, and pull the one for the radio.

 

Interesting thought for my issue. My radio doesn’t work. Wonder if related. Fuses are ok. Red security light on radio blinks but can’t get radio to ever work...

 

1-All cabin lights do work

2- I did not pull the fuse on the security system because I have it on “valet” mode, and even when activated there is no drain according to the multimeter.

2-I did pull the radio fuse 3 years ago because it is an aftermarket Alpine. Made no difference, as I recall

 

Here is a video. Car stays at 28 goes to 58~60 as the security system bleeps and only goes high if I arm/disarm system manually. No drain showing

 

27mA is very low and I would not worry about that. If you do short trips as you said the battery is not charging.

I had this issue when I lived in Sydney and drove my XJS daily to work. Work was 7 min away so I charged the battery regular.

 

That figure seems fine. Also remember you cant accurately measure the locked state battery drain unless you've got the meter on the outside with the boot shut. When the car arms, it takes a while to settle the systems before it goes into rest state and the current flow drops to a normal state.

Paul

 

Thanks Paul—

The trunk is “shut” , as I pressed the lever, engaged the lock and the lights went out. As if the trunk was actually shut.

If you take a look at the video, you can see I start with the car disarmed at 27, you can hear as I arm it, and then it goes from 27 with spikes of ~~59 as the security led lights up every so often. ......but still no drain.