post #15
use a meter

 

I assume this was meant for me, as I posted #15.
I don't understand.... 'use a meter'.
Of course I used a meter for the millivolt drop method, it was just too tedious and more difficult to get good contacts. Easier to pull a fuse you can barely reach than to get two probes on the rear contacts. Plus, dealing with millivolt, it's such a small drop it's easy to misconstrue information.
Using amps, it either drops or it doesn't.

 

Maybe not undersized enough to burn up but if you measure the resistance and gauge as opposed to more common automotive wiring it is.
Whether they were trying to save weight or money I dont know. Also if you remove your interior and look at the way it is run there
are many unsupported stretches where it can easily get crimped or rub thru on the surrounding metal.

 

No, it was meant for the post just before mine, by d a

Sorry you were confused.

 

I don't know why, either, (maybe both) but fortunately we're not seeing posts about it causing lots of problems (or any?).

 

actually undersized wiring will use more electricity due to the higher resistance as some of the power will be converted to heat thru the extra resistance and the rub thru can cause parasitic losses or shorts tat can be hard to find without pulling everything from interior and inspecting every wire and Jags seem to have a lot of both those problems so it may be a factor after all.

 

@d a here is a video link that will show you how using an Amp Clamp meter as Cee Jay suggests:

https://us.autologic.com/news/testin...e-voltage-drop

 

Thanks, great video.

 

and you just confirmed that you do have a convertible...You better get that back seat fuse box diagnosed man cause that fuse box controls your theft system,drains the power,and it will cut your car off in the middle of nowhere and you won't be able to crank it back up when it decides it's really going bad.Don't ask me how i know cause i was in a bad neighborhood in the ghetto when i thought the alternator went bad...and I soon found out it won't the alternator when my car was experiencing some sort of security issue when i took it to a shop for diagnosis that pin pointed me to where the problem was.I get my lil bro to do all my mechanical work,so i got him to change my fusebox out for me and replace it with another 1 and never had a problem ever since.

 

That's not right. The extra resistance (if it mattered) will reduce the current and thus (via I*I*R) reduce the overall power.

 

We owned a Jaguar S-Type for 8 years as my wife’s daily driver for work. At 6 years of age, temperature, age, whatever; the car developed a phantom electrical drain as well. My informational searches revealed that this kind of drain can occur with the loss of insulation around any copper wire allowing it to come in contact with metal and thus the slow drain. I found via this site a device called “PRIORITY START”. It connects to the positive terminal of your battery post & becomes the connection point for your positive lead to your car. Via its circuitry it monitors the energy draw from the battery, especially when the car is turned off. In the event the battery charge declines too near the preset point above the minimum charge needed to start the car; the device shuts off and stops any outgoing charge; thus preserving the battery to start the car. The device is deactivated by the act of stepping on the brake prior to activating the ignition. When a car battery drains to the point of not being able to start a car, (regardless if you jump start it or use a battery charger) once this has occurred twice or more with the same battery, it dramatically loses capacity and your trickle charger will not be able to save it. As far as electrical motors within the car (power steering, windows, even idle memory) once the battery is completely discharged (dead) or removed for a long period of time; the capacitors that maintain memory also deplete and so these and other components need to relearn once a new battery is installed. it is recommended to take the car out for a short drive at various speeds & operate windows & top so they can relearn their settings. As far as the key fob trick, That’s British electrical engineering for you. An intentional secret back door to get around situations like what you experienced.

 

Truly love these posts.
And they confrim that this is a White Whale that I'm not gonna chase.
For now, after reading every possible battery thread (and GRAD SCHOOL requires less reading than battery threads for our cars), I've created this shut-down technique. We'll see if it helps:

With the car in park but before turning off:

1) Turn off radio (push volume dial)
2) Turn off power to infotainment system
3) Set parking brake

THEN, shut off engine. Finally,
4) double-lock car (lock, wait for mirrors to fold back, press "lock" again)

Will this help? Who knows? I'll keep y'all posted.

 

PK, as you are in LA and not in SF (where parking at a forty degree angle is normal) I wouldn't set the E brake. If you should have a battery problem, it is easy enough to get your car out of "Park" but getting the E brake to release is another matter.

 

Interesting. Thanks!