Hey everyone,

my car-hifi-workshop installed a small subwoofer into my passenges foot space. It’s a 1993 4.0 Daimler XJ40.

But now the car has no ignition. They even uninstalled the sub again the check if there is a connection.

They are pretty sure that the car‘s immobilizer was activated in any way during the installation of the subwoofer. And now the have no clue how to get my car running again. The had some phone calls with the local jaguar dealer but they can’t help with „such an old car“…

Any suggestions????

Thanks in advance!

 

did they hit inertia switch while doing their things there?

 

Hi DocBottster,

Will the starter not crank, or is the car completely dead with no lights on the instrument panel when you turn the key?

The inertia switch that xjack mentioned is in the outer corner of the driver's footwell, assuming your car is Left Hand Drive.

Have they checked all of the fuses in the right and left A-pillar fuseboxes and the center fusebox in the center console? I seem to recall there are at least two fuses that will disable the instrument cluster and starting circuit, one of which may be in the center console (related to Accessories?), and the other possibly in the A-pillar fusebox. Sorry I can't remember more specifically.

Another possibility is that they may have disturbed the wiring to the relay module below the glovebox that contains the starter relay.

Also, they could have disturbed the wiring for the Central Microprocessor (CPU), which controls the starter logic. The CPU is mounted on the bulkhead just to the right of the transmission tunnel.

You can download the wiring schematics for your car at this link:

Jaguar XJ40 Electrical Guide 1993

The Haynes repair manual can also be helpful in locating relays:

Haynes Jaguar XJ40 Repair Manual

Cheers,

Don

 

Problem solved. Thanks guys!

 

Come on, DocBottster!

You've got to tell us HOW the problem was solved!

The only compensation we get for taking the time to respond to your request for help is to learn from your resolution of the problem. Don't leave us hanging!

Cheers,

Don

 

Don, i think he's left us for caribe with his newly purring cat and we may never uncover this mystery...