Hi Guy's

Seen a lot of good tech info come by here since I started driving jaguar.

This morning I bought my third jag a 98 XJ8 3.2L
The car had been out of commission for just over a year parked outside but the owner always kep the batery charged and sometimes had the motor running for a while. It has 170.000km on the speedo.

After collecting the car and some cleaning A test drive showed everything was working just fine except this one message on the dash charging system fault.

the strange thing is there is enough voltage car start fine everything works and the battery doesn't drain but the charging voltage is way to high I think.
with engine of it's in the high 16 volts and with engine running it's 17,4 Volts

The problem wasn't there when the car was stored any idea's on what's the problem ?

 

Definitely too high, and I'd say the voltage regulator is bad, inside the alternator.

 

Thanks.

That's exactly what i was afraid of to hear, means I have to take it out.

I was kind a hoping there could be another explanation or that it could somehow get stuck after standing for over a year. gues that's just wishful thinking.

What's the risk driving with it as I can't take it out this instant ?

 

The risk is that too high voltage will damage all the electronics in the car, and there's a LOT of electronics.

I personally would not drive it like that.

 

I had the problem of overvoltage from the alternator on my 1998 XJ8. The dashboard lit up like an Xmas tree with multiple failure messages, the windscreen wipers didn't work, the gearbox would only select 4th or reverse and both headlight bulbs blew. A change of alternator and everything was back to normal.

 

Funny thing is i don't have all that!!
I just get the message no other errors and everything works just fine.

I would expect lightbulbs to blow and all kinds of eletrics failing but none of that.

Just for safety if i have to drive i turn as much electris on as possible

 

Another strange thing.

This morning I took the car to the garage for a new APK which is the same as MOT in the UK.
We talked about the charging issue and did a new test, to my surprise the reading was 14,5 volts with all users turned of so it's charging and with the right voltage.

but i still get that message displayed and can't seem to reset it.

Any suggestions as to how to clear that message ??

 

You can try a hard reset, disconnect the neg. battery cable and touch to the pos. post for a few seconds. If that doesn't work, it will be necessary to connect to a code reader and clear the code.

 

Hi RJ

Thanks already did that this morning, First at the garage we connected a code reader (launch and a simple one) but no error codes stored.

Then when I got home I disconnected both the ground and positive cable from the battery and held them together for 60 seconds.

it still says charging fault in the display and both battery lights burn constantly

Could this have something to do with the false bulkhead stud connector ? I just had a quick look at that and it seems there is a bit of rust on it.

 

It could be that, but I recall from a recent thread it is more likely a alternator or voltage regulator problem. Try doing a search for charging system fault.

 

Hi Again

Did the search you suggested and found a few options.
Looks like the wire to the battery control light could also be causing the problem or even more simple corrosion on the connector at the dynamo.

Not looked in to it yest but will do that this week after I made some room in the garage.

Will report any finds.