I don't have any pictures, but my '94 XJS, LHD, came with both, a positive and a negative battery stud on both sides (driver's and passenger's sides). I know this because I've used them all several times. You can for sure jump start the car from the firewall's passenger side positive battery stud, or you can charge the battery at that stud, as well. Just use a volt meter to determine which stud is for what, very basic stuff, unless you still have the red and the black rubber boots.

But, as I said in previous post, the best is to avoid headaches by making your cigarette lighter receptacle hot at all times. This is standard for a good number of car manufacturers, including German cars and it is so helpful for charging USB devices, using a 12v vacuum, or tire inflator and what-do-you-know... charging your battery.

 

On my '96 the left terminal on the firewall is 'hot 12V and it has an extension running over to the right side stud which is of course also 12V . There is another smaller stud on the right firewall that may be a ground. Ground/earth places are plentiful on these old cars because they were made of metal.

I connected my maintainer in the trunk/boot directly to the battery and ran it out at the right corner just under the lid. I installed the little plug that comer with the maintainer to this wire. When I leave it will unplug itself. If you back out of the parking space the front mount would serve better. I don't know about you but I forget to unplug it pretty often. Right and left are looking at the rear of the car.
Cheers, RagJag.

 

That extension is actually the heavy gauge cable that comes from the battery in the trunk to the engine compartment, where most of the power is really used. It is routed along the right side of the vehicle and connects, first, to the right passenger side firewall stud, then it continues across to the left, driver's side stud where this cable ends.

Systems are connected to the right stud (such as the starting system) and to the left stud, so it is interesting to take a good look at the power distribution electrical diagram; it provides great info that comes handy when something electrical goes wrong and you need to isolate the source of the problem.

Cheers,

 

Hi!
You are right about the location of the firewall voltage terminals.
There are 2 posts on the firewall, the one closest to the hood latch is the
ground (-) terminal and the one near the air vent tube is the positive (+) terminal.
See the attached photos. One photo shows the charger connector hanging out the front grill.

Charger connections on the firewall




Negative post near hood latch. Positive post near
vent tube.




Charger connector hanging out grill

 

The locations shown are for a 1994 XJS 2+2 (US).
I've done the same type of connection on my 1999 XJ8 VDP.
The voltage connections are in different locations on the XJ8. The positive
connection is on the fuse box behind the drivers side head lamp. The negative
connection is on a body grounding post near the drivers side headlamp
and I used the same type of charger connector.
VERY convenient when the battery dies and the car doors and trunk is locked !

 

Pls see attached pic.
It's a 96 XJS 4.0L conv.
Would this be the positive battery terminal in the engine compartment?

 

I use a DVM (Digital Volt Meter) to check voltages before making connections.
DVM's are not that expensive now. There are coupons on the occasion at discount
hardware stores like Harbor Freight where you can get a DVM for $0.0 !
I have several DVMs as part of my tool kits.
You should read +12.6VDC or better without the ignition on at the firewall
connection. Trust, but verify!
P O R

 

I just saw an ad for battery charger/maintainer for my RV trailer that uses the
OBDII connector as the charging connection.
I haven't looked at the electrical schematic for the 94 Jag 2+2 4.0L yet to see if
the OBDII type connector in the truck will work as an input yet.
It does offer an eyes on the battery that is in the trunk when connecting the charger.
Otherwise it would require opening the trunk to connect a battery maintainer.
I like the small connector poking out the from grill to connect the charger.
Very convenient.
"Falls easily to hand" as the quote from some of the old
Road and Track magazines to describe how easy some aspects of a car were
to access.

 

Do 1994 Jaguars have an OBD? In America the OBD came standard on all cars. I know my OBD connector is under the left side at the drivers knee.
RagJag

 

I don't know if the '94 has a "OBD II" connector yet. I know that the Jag Techs connect
their "whiz Bang Analyzer" to some sort of connection in the trunk.
It allows them to update the security computer and do some other
whiz-bang stuff with the engine.
I don't recall seeing a OBD II connector under the drivers (LHD) side when I repaired the
A/C blowers a few years ago. I will look for it tomorrow.

P O R (Press On Regardless)

 

I am looking for that rubber cover or boot for positive cable that goes from the firewall to the starter. If you have a good one let me know.
Snowball