I have an 04 Xtype and love the car. Recently it has developed a Batt light issue. The light comes on after engine start, but not cosistantly. Sometimes it will not come on. I have had the Battery changed and check the charging voltage while idling...it's around 14V at the battery.


I am ready to seriously attack the problem now. Two things:
1) Nothing consistent / noticeable that initiate the light
2) No noticeable power drop when driving..I can turn on lights/Hibeams, a/c blower on high, After market radio on high and no dimming or sluggishness


Advice appreciated...Thanks

 

Gray, what I want you do is when you start the car, press and hold the TRIP button on the left stalk. Keep holding the button till you see the message center say "TEST" or "ENGINEERING TEST". At this point, release the TRIP button. From here, tap the TRIP button till you see the display read "BATT XX.X" where XX.X is the voltage that the computer is seeing. You will have to hit the TRIP button about 30 times and just before you get to the BATT reading, you will see "TRN-X" and then "IVD XX" (will take about 25 taps of the TRIP button. When your car starts to act up, what is the value that the display is indicating? That will help me narrow down if you have an actual fault with the wiring of the car or you have an instrument cluster issue.

 

Thanks Thermo,
I will do this in the morning and let you know the result. I also have a OBDII reader if it helps to read any PID's

 

Well,


Turn the Cat on this morning and watched the Gage values on the instrument panel. Also drove the car while it was in this mode. Here are the results...


Sitting Idling Driving
Bat reading 132-135 135-125


While driving I turned on the heated seats, A/C, blower to 80%, Radio and the Head lights. The lowest reading was 125. Interesting I stop several times and cut the car off. When re-started the light came on within 1-2mins. However the last time the light did not come on and I had all the utilities mentioned above on and the voltage dropped to 12.5.

 

Gray, based on what you are seeing, this leads me to believe you have either a bad alternator or a field wire that is starting to go. I base this on the fact that when you are driving, the voltage drops (ie, the motor is at its hottest). With a field wire that is loose, it will cause the voltages to bounce around and give you what you are seeing. But, it can also be something internal to the alternator too. Without putting a multimeter on the lead going to the alternator as the motor is running, hard to distinguish the two apart from one another.

 

Think these are the tests Thermo was referencing - nice doc to have around...

X Type codes towards bottom of doc.

Hope this helps.

 

Interesting, in addition to this, there is an occasional sound in the engine compartment that is similar to a bearing sound. I had it at the Jag dealer a bit ago and they mentioned (if I recall) that the A/C was starting to go. I have been looking the A/C but no indications. I am wondering now if the sound is the Alternator bearings since the two units are near each other.


Thermo, when I watch the voltage on the Instrument panel during driving it does float from 12.6 to 13.5 and it's not linear (meaning increase /decrease with speed). Is the voltage supposed to be steady?


I have access to a 04 2.5L Jag that just showed at UPull. I think I will go get the alternator and A/C clutch tomorrow. What do you think?

 

Just a quick note to check your battery cables.

I had very similar battery light issues. In my case, the battery cable connector crimp had too high a resistance. The connectors would occasionally get hot and the battery light would come on. Similar voltage readings and odd behavior to yours.

I cut my cables, cleaned, reworked the connectors and "presto" it's working 100% now. That was 3 years ago.

 

Gray, if you can get the parts that way, may not be a bad way to go.

As for the voltage, it should remain fairly steady regardless of the engine/vehicle speed. So, having it wander is questionable. I would do as the PDF says and go from there.

 

Okay guys


Is there any other way to remove the alternator other than removing the A/C compressor (which means purging the system)? I can't believe how much "crap" is crammed under the hood of the Cat...


Thermo - I hope you have something...


If not, how do you get at the top (2) bolts on the compressor


Thanks

 

Gray, i know you are going to think I have lost my marbles, but first start by removing the bumper cover. This will give you lots more room to work. If I remember right, you don't need to remove the compressor per se, but you may need to unbolt it from its mount (leave the lines connected) so you can get a little bit more room to access the bolts. But, i also seem to recall that other members have removed the alternator without unbolting the A/C Compressor.

 

Thanks Chris,


I will take a look. I saw the bumper cover yesterday and wondered if removing would help. I will also scan the site for alternator removal. I want to look at it on my Jag before going to the salvage yd to spend the time. I really don't want to open the A/C system if I don't have to as you can imagine.

 

If you go the route of removing the bumper cover, I would love to see the pics. When I replaced the alt, the only way I saw to get to it was to disconnect the a/c compressor.

Now I am having the battery light come on every couple of weeks. Made the mistake of charging the battery when taking it to the shop to have checked. They said all was well, bring it back when it acts up again.