New Owner 1994 XJ81 V12
#61
XJ81 Electrical Manual
The XJ40/81 range is a rather complicated car when it comes to electrical issues, and it is totally different from the XJS range. It is critical to use the correct wiring diagram. Find the correct electrical manual attached.
Instrument lighting and power is managed through switched ground by the ignition lock switch (page 20). You will need to check if you have proper switched ground there.
I would strongly suggest to use this as a starting point and then get to the starting issue later.
Instrument lighting and power is managed through switched ground by the ignition lock switch (page 20). You will need to check if you have proper switched ground there.
I would strongly suggest to use this as a starting point and then get to the starting issue later.
#62
I agree with the focus on the ignition switch as a starting point
The ignition switch needs to provide a ground path / enable and is wired the same as earlier
Notice your Linear gear position switches ( near the gear shift box top side ) has to have a ground stud path and possibly the connector / splice in your battery pic post # 24 ( but that looks to be the positive post terminal cable )
This path can be seen on page 22 of the V12 X40 wiring guide as the 20 inverted triangle point
But this path is buried in the center console to verify ground path so that brings you back to verifying the ignition switch which is easier to check
The ignition switch needs to provide a ground path / enable and is wired the same as earlier
Notice your Linear gear position switches ( near the gear shift box top side ) has to have a ground stud path and possibly the connector / splice in your battery pic post # 24 ( but that looks to be the positive post terminal cable )
This path can be seen on page 22 of the V12 X40 wiring guide as the 20 inverted triangle point
But this path is buried in the center console to verify ground path so that brings you back to verifying the ignition switch which is easier to check
Last edited by Parker 7; 10-04-2022 at 10:43 PM.
#64
Dead in the water and don’t know what to do
Hey, sorry guys I have a lotta questions and I hope you guys can help me. I have a 1994 jaguar XJ 40 with a V 12 I’m dead in the water right now we’re gonna a while ago, but could not get anything different to happen I have no power to nothing, but when hook the battery up the security thing in the middle Consol lights up but none of dash lights my headlights light up. Can someone please help me I don’t want to give up on it What size of battery in cranking power should I need? Just checking
#65
You already got a lot of help in this thread https://www.jaguarforums.com/forum/x...-263423/page4/ All the details are there. You will need to provide some results from tests so members can continue to help you.
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Don B (11-29-2022)
#66
Hi Jmains123,
I have merged your new thread with your previous thread. Please do not start any more threads on this topic - please keep all your posts in this thread to avoid duplicate effort and confusion on the part of other members.
What steps have you taken so far to troubleshoot the symptoms?
Cheers,
Don
I have merged your new thread with your previous thread. Please do not start any more threads on this topic - please keep all your posts in this thread to avoid duplicate effort and confusion on the part of other members.
What steps have you taken so far to troubleshoot the symptoms?
Cheers,
Don
The following users liked this post:
93SB (12-06-2022)
#68
Please check fuses A3 and A5, left fuse panel. Replace if blown. Only if both are okay, next check the ignition power relay. It does provide power to a number of circuits. It's hidden behind the center console panel. In order to get access to it, you need to remove the radio at least. Please see the attached photo - it's the blue relay on a black base.
Please post your results.
Please post your results.
Last edited by newyankee; 12-09-2022 at 06:57 AM.
#69
Please check fuses A3 and A5, left fuse panel. Replace if blown. Only if both are okay, next check the ignition power relay. It does provide power to a number of circuits. It's hidden behind the center console panel. In order to get access to it, you need to remove the radio at least. Please see the attached photo - it's the blue relay on a black base.
Please post your results.
Please post your results.
#70
#72
#76
Referencing the relay map the relay in the center of the dash is the ignition on relay often referred to as ignition positive relay on normal cars
This relay powers the engine ECU ( error )
The starter relay is on the car's far right but not needed to check just yet for the starting sequence
By the ignition on relay clicking it does prove you have the correct ground command for the center , left , and right fuse panels through the ignition switch ( error )
This relay powers the engine ECU ( error )
The starter relay is on the car's far right but not needed to check just yet for the starting sequence
By the ignition on relay clicking it does prove you have the correct ground command for the center , left , and right fuse panels through the ignition switch ( error )
Last edited by Parker 7; 12-11-2022 at 10:21 PM.
#78
#80