Hi everyone.

I have a problem with the battery light staying on after I jump started my car. I thought it may be the alternator again as I had it reconditioned in January. I have been back to the alternator man he has bench tested it and said it is fine. It is charging the battery.

I have also noticed that my front and rear heated windows and my window washers are not working. I have tested all fuses to see if any are blown but all OK.

Can anybody help please.

 

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

 

A little more history may help. Was the battery light extinguished as normal before the car needed a jump start?

Most aftermarket replacement alternators will charge just fine, but don't communicate properly with the circuit that controls the battery light. The end result is the light stays on all the time. Some people have reported good results swapping the OEM alternator's internal control module into an aftermarket unit.

As NBCat has suggested, what is your battery voltage before start? Since your battery had run down enough to require a jump start, that poor thing needs to be fully recharged before any troubleshooting. Don't count on the alternator to replenish a depleted battery. It was never designed to do that.

 

Hi people sorry it has taken me so long to get back to you all I have not been very well car was running ok before I jump started it I have put a diagnostic scanner on the car it is telling me code p0622 Generator field/F Terminal circuit/charging circuit fault, I also tried an other alternator it is still the the same as before on that any advise would be appreciated thanks.

 

Hi people I for got to mention that the battery is showing 12.56 volts with ignition off and 13.72 charging

 

Hi everyone this is a repost I am still having electrical problems with my s type diesel as posted previously this all started after jump starting my car the battery light stayed on I had my alternator reconditioned January The battery is holding a charge of 12.56 volts before starting and charging at 13.72 started, apart from the heated window and jet wash problem, As of this morning it now has intermittent indicators and a gearbox fault can anybody help please.

 

Hi Guy's and Girls don't seem to be getting any feed back about my electrical problem, do any of you know of a good jaguar auto electrician i can contact please.

 

Geoff,

I've merged your two threads with the same title as members who have already responded to the original will probably not look at the second version.

To summarise:

1. new alternator fitted
2. jump started
3. battery warning stays ON
4. alternator checked OK
5. diagnostic code P0622
6. battery is showing 12.56 volts with ignition off and 13.72 charging

I think that catches all the details?

Graham

 

Thanks Graham

 

Hmm, both of those numbers are slightly low.

Have you put the battery on a charger yet? Not a trickle charger, it won't cut it. Not enough oomph. I highly recommend an automatic charger with at least a ten amp output. For any kind of electrical troubleshooting, especially with the charging system, you have to begin with a fully charged battery. You can't rely on the alternator to do it. So if you don't have a charger at your disposal, please beg, borrow, or steal one and make sure your battery is fully charged before doing anything else. This step is very important, please don't skip it.

The 12.56V prestart you recorded is below limits. These cars, especially 2003+, are VERY finicky about the prestart voltage. From forum experience, 12.6V or higher is what you need to see. That is a VERY high standard. Don't judge the battery state-of-charge by how fast the starter cranks. This isn't like an old Vauxhall. Before proceeding, please make sure the battery is fully charged and reads 12.6V or higher prestart.

The 13.72V while running also seems low. 2003+ cars have a smart charging system, that runs around 14.5V after engine start, slowly tapering off to around 13.5V after several minutes. If the highest you're seeing is 13.72V, something ain't right. Some of this could be caused by a battery in marginal health, barely able to take a charge. Think of trying to inflate a balloon with a hole in it. I would suggest having the battery tested. Most auto part stores will do so for free. If the battery is more than 5 years old, and has been run down enough on several occasions to need a jump start, it's probably time for a replacement.

I've never seen the P0622 code before, and couldn't find much detail about it. The generic definition is a problem in the alternator field circuit. What year is your car? I guessed 2005 or newer. Please see figure 02.3 here:

http://www.jagrepair.com/images/Auto...cal-2005on.pdf


The alternator is at the bottom right corner of that diagram. See the wire leading to 38 inside a square box? That's the field circuit. Follow the #38 out to figure 01.2, and you will see this circuit is fed battery power via fuse #F30 at the rear power distribution box, next to the battery. Make sure this fuse is good and fits snugly into the fuse panel. I don't think the alternator would charge at all if this fuse had blown, but who knows. Perhaps the charging system defaults to a backup charging mode? That might explain why you're only seeing 13.72V max.

 

@Geoff Jags, replace the battery and report back. Many of the issues you're describing are the result of a failing or weak battery. Once the battery is replaced, continue reading the voltages to see if the alternator is knackered.

 

One reason that this thread has not had quite as much play as most is that the 2.7 diesel was never imported into North America; many forum members just pass it over as they have no experience with this variant.

That said, I am still left wondering if the OP had his original alternator re-built by a firm that is really familiar with Jaguar units; also, if the second unit tried in the car was an exchange of a generic rebuild which does not conform to Jaguar specs on the voltage regulator...

 

Thanks for your advice Guys I will get back to you cheers.

 

Hi Karl can you tell me if the feed from f30 fuse go's directly to the Generator/Alternator or through the ECM/ECU and should the Generator/Alternator have a permanent live on the three pin plug going in

 

Fuse F30 feeds direct battery power to pin #1 at the three pin connector on the alternator. This circuit does NOT go through the Powertrain Control Module. If fuse F30 is good, you should see battery power at pin #1 at all times. I had been thinking this was power for the field circuit, but I was less correct than usual. Per the service manual, this is the voltage sensing circuit, and is feedback to tell the alternator what the battery voltage is at any given moment.

I found a little more detail in the service manual, scroll down to page 2764 here:

http://www.jagrepair.com/images/Auto...M-Workshop.pdf


Your P0622 fault code is found on that page. Note it's actually an enhanced 7 digit code (P062200), but your scanner isn't reporting the last two digits. The generic code reported by your scanner isn't quite correct. Per the service manual, the official Jaguar definition for that code is Generator Monitor Circuit Plausibility. Follow pinpoint test A given on that page for your fault.

Those tests are fine and dandy, but are written by an engineer, not necessarily an experienced troubleshooter. Unfortunately, sometimes there's not enough emphasis on some of the basic prerequisites. Reading between the lines, you've said you've had this car for 4 years and all was groovy until you needed a jump start.

Big question here: Was the battery light illuminated before needing the jump start? This is a huge clue, and will direct the troubleshooting direction.

If yes, that's a charging system fault, such as a bad alternator or wiring issue.

If no, the battery itself may be bad, or is being discharged overnight by some undiagnosed drain. At the very minimum, make sure the battery is fully charged. I've already mentioned this, but nothing in your reply confirms if you've done so. This is VERY important. I can't stress this strongly enough. If any doubt about the condition of the battery, just replace the poor thing. I'd hate to see you chasing your tail trying to diagnose a potentially nonexistent charging system problem, when the battery itself could be the root cause.

 

Hi karl the battery light has only come on after jump starting I am in process of tracing wiring back to alternator battery is fully charged had on for 15 hours will keep you informed.

 

Hi everyone just an update on my electrical problem I think I have sorted it many thanks to all you advice and help I traced the wire from rear fuse box in boot which is a thin drown whith green strip on a 5 amp fuse be carful the are several other wires slightly larger same colour it go's through to the front fuse box area into a multy block were it changes to a slightly lighter brown with green strip from here it go's through the bulk head under the front wing /fender around the front of car to passenger side under pasenger wing /fender and in to engin compartment to a large square multi connector just in front of pollin filter the wire changes to red and go's to alternator. I found that when I had don some repairs I had cut in to the wiring loom and caused a short circuit the cars not back to gether yet so hopefully everything will be OK.