I have a 2003 Jaguar S Type with about 130000 km. I got this car last fall after our XJ8 died, and it’s has an usual quirk. On startup there simply no power to the electronics in the car for about 20 seconds. So the engine starts, but nothing lights up on the dash, there’s no power to the steering, power windows, Door locks, stereo, air conditioning, nothing for 20 seconds.

so I do the count down everyday after I start up and after 20 seconds, the dash lights up and all the gauges flip up, the windows, seats, stereo everything comes to life.

anyone else seen this in their Jags.

 

Are there any DTCs stored? If so, post them here.

What is the battery voltage across the terminals with the ignition in the OFF position when checked with a voltmeter?

 

Once you've started/driven it, does it happen if you turn off the ignition & restart ? Maybe a connection or something needs to warm up to make a connection/start working.

 

Definitely an odd problem. Doesn't seem anybody else here has encountered that.

A few free things to try:

With the engine cold, turn the key to Run but not Start. Do you still get the delay?

Repeat with engine warm. Key to Run but not Start.

After driving for a while, try switching off the engine and then starting right back up. Do you still get the delay? Or does it only happen after a cold start? (Edit, I see this was already suggested, but I'm thinking mostly of the battery charge.)

I'm not exactly sure yet how to interpret the test results. I'll have to put on my orthopedic thinking cap. I'm mostly wondering if this is a power supply issue, such as a relay acting up. Or maybe it's a valid response by one of the computers for reasons still unknown.

 

It's like a very very slow relay kicks in or something.

Unique

 

The fault seems very repeatable, so how about this? Open up the three fuse panels, so all relays are readily accessible. Turn the key to begin the 20 second delay cycle. Place your fingertips on as many relays as possible, and wait for everything to power up.

​​If a relay is part of the equation you'll feel a click as the power comes on. Check all relays at all locations. If you find anything, please let us know.

The next step would be to determine if the relay is getting the proper command but is very slow to respond. In that case, rob a similar relay from a known-good system and try again.

If a relay is slow to click but swapping another in its place was no help, you'll have to check the signal to the relay. For whatever reason, the signal is being delayed. That will be harder to figure out.

 

One more thought, offered for free and perhaps overpriced. I've never experienced it on my Jaguar, but I do know other Ford family vehicles of this era have a load-shedding feature to keep the engine running in case of a major electrical failure. The logic is to shut off non-essential circuits to preserve battery power to the ignition system, fuel pump, etc. This keeps the engine running for a few extra minutes so you can safely pull off the road. The kicker is none of this is annunciated. No warning light, no message, just a bunch of stuff suddenly stops working. You're left scratching your head while driving.

If our cars also have this feature, perhaps it is activating as designed in response to an electrical problem, such as a weak alternator. To check, hook up a voltmeter to the battery posts. Record the prestart voltage. It needs to be at least 12.6v, a VERY high standard. Next, start the engine. On a 2003+ model, you should see about 14.5v right away. After several minutes, the reading should slowly decrease to approximately 13.5v.

 

I really appreciate all the feedback here, love this forum.

The previous owner had the dash instrumental panel replaced, I think the issue is somehow related. Its the same regardless if the car has been sitting and its a cold start or a restart after its been running or driving. I've tried the testing the fuse box as Karl suggested, haven't been able to identify any relays that seems to kick in with the electricals,

I'll keep exploring and will post any findings.

 

That's unexpected. Was thinking lazy relay or fracture in a circuit connection.