Just bought a 98 XJ8 and it needs all new electric system, what should I do to ensure I should invest the cash to get her running? Engine is free, body is amazing! Lots of electric issues, may have be in water???

 

"New electrical system"? You make joke, right? Your choices are a) buy another car for parts b) use parts from this car to make another car better C) Pay AT LEAST 5 times the value of the car for the parts to fix this car in the used part market

 

Welcome to the forum, I hope we can help you.

There are, if I recall, a total of 35 computers, several hundred assorted sensors and several miles of wire/cable in this car. An 'all new electrical system' (even from the junk yard) will likely cost more than the car did brand new and take you longer to replace than the original design team spent on development.

Here's the 98 electrical system diagrams, to give you a realistic idea of the XJ's complexity: http://www.captainjaguarscathouse.co...ec%20Guide.pdf

How about, instead, describing your symptoms. Perhaps we can help you converge on specific issues to deal with.

 

The car is completely solid every panel all glass and interior are in excellent shape. It wont run is the issue, wont even turn over, due to electrical problems. I could buy used sensors and computers but how can I ensure it runs before I start putting cash into it.. Ive got a bit of wiggle room on repair cost because as you may have guessed I got her cheap!

 

First things first.... Is the battery good? Do any of the dash lights, radio, come on when you turn the key? If so, can you hear any clicking (solenoids) under the hood when the key is turned? You got to be more specific. Unless you open the hood and see nothing but a mess of cut-up wires like wolverine was in there, I highly doubt you need a whole new electrical system, in which case I'd burn the car and get insurance money....

 

First thing to do is to get the engine to turn over. Start with the battery. It would be hopeless to start replacing parts and very expensive. See if you get current to the starter. See if the fuel pump runs.

 

The simple fact that it won't turn over certainly does not imply that a new electrical system is needed... it can be as simple as a depleted or dead battery, a blown fuse or a loose connection, or it could be as bad as a seized engine.

Describe the exact symptoms - what works and what doesn't, and under what conditions, and perhaps we can help you converge to a solution.

 

if as you suspect it's been in water, you'll need to strip it completely and use the electrical system off a 100% working donor vehicle, ask me how I know.......

If it's just gremlins, we need to know what works and what doesn't, does it actually attempt to power up and do a system check? are there any audiable warnings, lights etc? Like any complex car, they need a good battery. This would be the only thing I would invest in at this point, and a good multi meter.

 

The "may have been in water?" is a question, not a statement... I suspect he's seeing a bunch of error messages, and since it won't start, is jumping to this as a conclusion, when we know that this is common with the XJ.

Again, what are the symptoms - what error messages do you see, what works and what doesn't? Excruciating detail is needed to help you, and the issues, hopefully, will than you initially think.

 

I have power to locks, windows, radio, dash, but it will not turn over, zero power to starter? Is there a way to isolate the enginge from the sensors and just start it? Thanks all!!

 

You need to open up and be verbose - you stated: "Lots of electric issues"... what are they?

When you turn the key to the run position, what do you see? How about the start position? Are there any error messages scrolling across the speedo display? Help us out here - without a lot more information other than 'zero power to starter' we can't help you.

BTW, unless you measured voltage AT the starter, how do you know that there is 'zero power to the starter'? It could be there, but the starter motor is dead... see my problem? I suspect what you really mean is that when you turn the key to start you hear no indication that the starter motor is turning over, correct? Do you hear anything else? A relay clicking somewhere perhaps?

We need descriptive details of what you do, and what happens (or doesn't happen) in response, without assumptions like it's been in water or the starter has zero power or the entire system needs to be replaced. Then we can start to generate a plan to troubleshoot and conquer your issues.

 

Quadmaniac:
Actually, in his original post he said "it needs a new electrical system", therefore my terse answer. I would suggest to the OP that he can get a wealth of information here if he would be more verbose AND accurate. Tell us what's really going on!

 

Agree 100%; and same relative to MY first somewhat incredulous response. What's going on, firebird?

 

The engine cannot be isolated from it's electronics, it's controlled via sensors, if power is not sufficient to start it from the battery, you may hear a click from under the bonnet, and that's about all.

got to agree with the comments above, vague on the details firebird, more info required.

1st item - Has it got a good battery? i.e. minimum 12v

Check if there's power to the starter as suggested.

Check all fuses in the fuse box under the bonnet, and replace any if required (with same amp rating/colour). The power lead going to and from that fusebox, undo the nut and clean the terminals.

 

I'm assuming Firebird may not be familiar with modern computerized cars. B/c I agree, "a whole new electrical system" is extreme. Somewhat like:

"my toliet won't flush. I need all new plumbing in my house." which would even include new swimming pool pipes.

 

Firebird, consider this: most of the people who are desparately trying to help you are thousands of miles away. It's like trying to land an airplane over the radio. In order to get useful help, you must be their eyes, ears, and hands.

You *must* respond *directly* to the questions being asked in great excruciating detail. Guessing at the answer to the next question that has not yet been asked will get you exactly nowhere.

 

Thanks guys,
I have power to interior, radio, locks and such...When I turn the key I get nothing , no sound no clicking, Ive have checked numerous relay they are good, now I'm cleaning all grounding points to ensure a good ground. Does someone have a good wiring diagram? Thanks

 

But have you tried a new battery?

 

First get a history on the car to see if in fact it was a flood car. If it is walk away! If you are comfortable that it is not a flood car your next step is to get the car to crank the engine. Once you get to that point investigating the real problem if you have one. I hope this helps!

 

Gus,
Thanks I can't see the attachments, I'm working now to get the engine to crank, I'm cleaning all the grounding points now. Battery is good and has full charge...