For the v - 12 there are some extra relays and empty spots

Be back in a bit

There is a large relay that is the 2nd power to the engine ECU and is directly wired / shared with 12 volts " sitting " on the fuel injectors

Pic coming

 

double post sry

 

For the inline 6 as the # 5 left large relay is the 2nd power to the ECU used at all times

It is controlled by the ECU and brings power back into the ECU as the high current outlined in red with fuse X and y to the large relay

The 1st power is the small # 9 king relay in the corner of the right engine bay fuse box powering fuse 10 - 16 for the ECU

See page 17 and on

X300 1996 LWB.pdf (jagrepair.com)

Ask question but I'm going to crash for the day

 

Never mind the empty relay box (it has the white stripe). That would be used for the headlamps power wash, I don't think any USA cars were fitted with that. You can verify exactly which relay you are dealing with by the wire colors going into it. Sometimes the relay positions get mixed up.

The check engine light must be lit at key on to enable engine cranking. Did you try starting in neutral?

How is the battery? These cars take a lot of juice. Maybe get a charger. Short trips don't charge a battery well enough.

 

Never install the battery in backwards , mark with tape and an arrow on the batttery

Positive post fwd

recoverable if done backwards

Never over tighten the battery positive post nut , breaks curved nut underneath

In order to have all your starter agreements the Engine ECU must be powered along with the security module and BPM

The ECU is the right engine bay fuse box relay clicking which you confirmed

And the large # 5 ECU control relay , feel for click

The BPM gets it's power from the trunk fuse to go fwd to the glovebox area to the BPM

The power ( which you may have as a fault intermittently ) goes though large connector BT - 4 above the fuel tank ( looks the same as the RS - 3 and LS - 3 connector )

This connector should have a tie wrap on the large external lever clamping lock for best solid connection

Do not remove yet as this connector can be a pain to reinstall

Water ( from the fuel cap well drain clogged ) can sometimes get into the security module connectors that will be to the cars left of the BT - 4 connector

There is a hard reset for the security module and BPM for US models , this involves more than just positive battery cable removal

Ask questions

 

Specifically, to the starter rotating system to break it in half the large starter solenoid relay must click ( you must feel and not listen as others clicks in the area )

Do you have starter rotation ?

if no click the BPM is maybe not getting it's agreements in order that the BPM ( maybe not powered ) can then close the starter relay

You will not have a chip in key / immobilizer on US models

There are 2 starter solenoid relay fuses and where they get their power from

32 double hash circle is the right engine bay fuse box fuse # 12 which requires the right king relay to close which you confirmed

68 square is fuse # 3 left engine bay fuse box which is hot at all times not requiring the left king relay

 

There is a crash / inertia switch that can trip for no reason

it has a reset button but does not always reset ( Mickey Mouse internal switch parts )

You can jumper the 2 white wires on the switch connector with a paper clip

This switch disables the fuel pump and other things

This is a pic of a British right hand steering model and the switch will be on the right footwell far right side on all models , notice the right hand steering model gas pedal

 

thanks so much I’ve been looking for that switch!!


https://www.jaguarforums.com/forum/x...ts-etc-255370/

the problems this guy was having seem very similar, and would make since as I was messing around in the rear fuse box and trunk lock area the same day as this started. So I think ima start by checking there and the inertia switch!

 

I have left the car overnight with a damp towel covering a jumper cable connecting the positive and negative cables.

I have also removed the security module and sprayed it with electrical connector cleaner.

 

On security module ensure reinstall with positive battery cable disconnected

On hard reset time / process the Security module connectors must be on

The main battery cable goes through the lower right of the fuel tank to a 2nd megafuse / terminal post under the rear seat pan

This large terminal post nut has been found to be loose

Be careful to not drag the rear seat pan out the rear door opening

This for a like X308 , trunk relay/ fuse box different



Under the black spiral taped white bundle black plastic triangle

 

On hard sest the longer time the better

 

So I went through the whole car checking for loose wires, cleaning grounds etc.

I think I may have messed up my security and locking module unplugging it the wrong way or something.

The reason I think this is because the central locking switch has the red light lit up at all times. As soon as I attach battery this light comes on and stays on. I can barely find any threads mentioning this light. I can’t find anything in the manuals about it.

I did notice that I am getting less voltage when I hold the multimeter leads up to the positive battery cable and the alternator. About .4 Volts less than when I touch the battery terminals with the leads.

 

As current flows through the battery cables and restrictions on terminal post the voltage will drop

So the voltage will trade with the current restrictions under a dynamic / load picture

You can see this voltage sag as you turn on the cabin blowers as a load basis and not a current restiction

The hard reset should take the SLCM to zero state and not hung up in it's steps

 

Hey thanks for all the help. At the moment all my problems have been resolved but I’m still going to call them intermittent because I don’t wanna get to arrogant and have the car turn on me again.


What fixed my left turn indicators is changing the lamp control module. Immediate resolution to that issue when the module was changed.

What fixed the horn was a ground connection on the right hand side of the engine in the very front behind the headlight.

What solved my interior lights, no start, no crank, no wipers, stuck in park issue was a ground connection behind the steering column, I missed it the first time checking all my ground points because you need to peek the carpet back a couple inches to see it. It’s right behind the gas pedal.

As of now the car is running great. No issues at all.


Pretty simple fix in the end. Less than 100 dollars.

If you have similar issues. Don’t rush to replace BPM/SLCM, it is likely much easier and cheaper fix.

clean your connectors, clean your ground points. Make sure battery is at its strongest.

I’ll let y’all know if anything else goes wrong. Or the issues I was having re-emerge.