On Х-type ( 2003 MY, 2.5 ), the battery warning light on dashboard from time to time light on. Diagnostics doesn't show any fault. At a burning bulb pressure on plugs of the battery 14,6 V. Please tell in what a problem?

 

DVPV, out of curiousity, does the battery light come on at specific times? Ie, high RPM, whenever the dash fan is turned on high with the car at idle, etc... A common failure mode for this sort of problem is if you are getting the light with high RPMs (over 3,000), then odds are your alternator is on its way out. If you are getting the light when you turn on the dash fan (large electrical load), then odds are you either have a bad alternator or the wire feeding the field of the alternator is having issues. If you need more help with this, let me know.

 

Thermo,Thank you very much for the information. Tomorrow I will try to look at what RPM warning light lights on. Today morning the light didn't burn. After I have passed 20 miles, have made overtaking of two cars it again have lit up, the dash fan at that time worked on average turns.

 

Now I have passed with having included all consumers of a current, after 1 mile the light has lit on. I have muffled the car and after has got a warning light didn't on, having passed about 10 miles a light haven't lit on. With all included consumers on working engine pressure on battery plugs is 12.55 V.

 

The system uses an adaptive charging system. When u test it you will see it charge up to 15volts while the car is running. That's normal. Lastly i would check the positive battery cable. Let the car get hot, and then take water and pour it on the positive cable terminal on the battery, if it sizzles the cable is done. If it doesn't I still wouldn't rule the cable out. Do a voltage drop from the positive cable terminal, to where the cable connects on the alternator. Any high voltage drop like 1-2v and so on indicates a bad cable as well. Never seen bad alternator on these cars, doesn't mean they don't go bad. I've seen more bad cables then alternators.

 

You're Jag is doing the same as what mine did when my battery was about to go bad

 

I have changed my battery on another one not new but in good condition, but situation not changed.

 

DVPV, having 12.55 VDC at the battery is telling me that your experiencing a voltage drop between the alternator and the battery. With that being said, if you can, access the large wire on the back of the alternator and see what the voltage is there with the engine running. If you are getting 12.55 VDC there, then odds are it is an alternator issue. If you are getting say 13.00 or more VDC, then you have a bad power cable to the battery. If you need to know how to prove a cable bad, let me know. IT is an easy check.

On a side note, any wire that drops more than 1.000 VDC between the source of power (ie, fuse box or battery) and the input to the load is considered either bad or underrated for the application. I tend to use a slightly higher standard of keeping all wires from dropping less than 0.500 VDC between these points. In the case of ground wires, it would be between the output of the load and the battery negative/body ground.

 

Sounds like the alternator. turn the engine on. while sitting at idle, turn on all of your interior lights.
now, press the brakes... the Braking system will draw enough power to dim the lights if your alternator is poor....

 

Thank you for help, friends !
Yesterday has put absolutely new battery, warning light burned constantly with small breaks after engine start. Have checked up a wire from the generator to the battery everything is all right, a wire from the generator to ECU have spent new, but has changed nothing.
Just now measured at the cold motor ( weather now 10.4 F ) and the included headlights loading on the battery 15 V, warning light did not on. A problem with the alternator ?

 

DVPV, it may be that you have some corrosion on the plug for the alternator. One of the leads affects the current going to the field, which then affects the output voltage of the alternator. You get a high resistance connection in this lead, it can cause the alternator to act funny. You can try spraying the plug to the alternator with some contact cleaner and see if that helps.

 

Yea my tech checked electrical system (not sure how thorough) replaced my positive terminal, lubed them and put in a new battery for 400.00....talk about highway robbery lol. Keep in mind the battery he purchased originally for me was the one that went bye bye and this one is a new one (not a swap/replacement) so I felt burned by that as I could install the battery on my own and keep my OWN receipt.

 

As far as the terminal or the cable neither are expensive if you buy genuine parts online. I just don't know about installing the actual cable cause I don't know how difficult it would be.

 

Yesterday has put other alternator (used). The first 30 miles were fine, but today warning light has again lit on. Now when headlights are on loading on the battery 15.1 V. and at switched off 15.2V. Pressure on plugs of batteries at the switched off motor 13,3 V. All wires are Ok. Remains only ECU ?

 

Today I have passed about 10 miles, the warning light hasn't lit on. At voltage measurement on the battery the tester has shown 13.1 Volt when headlights was on and 13.4 Volta at switched off headlights. The problem stay not solved.

 

Thermo, how do you prove that a battery cable is bad? I want to check my positive cables.

 

ya how do you check this cable? and what do you mean pour watter and if is sizzles its bad?
do you mean if the terminal gets verry hot the cable is bad?
we have had a on and off issue with the battery light, its back now but it went away for the whole summer. i keep thinking that its just a crap battery but its new and it takes a charge, but i left the headlights on for 10 min with the car off and it was totally dead.

 

The problem isn't solved till now. After alternator check at the stand, mechaniks have advised to change the relay-regulator. Whether there is a sense?
Last week has lit up "check eng". Errors were the following; P0300 Random misfire detected, P1316 Misfire rate excess emisions, P0301-P0306 Misfire in all cylinders, P1632 Generator charge system failure, P1146 Generator C line low input, P1629 Generator front right line failure.
May be problem in ECU ?

 

Have you had the positive battery cable looked at, I've stated this before in other post. When there is enough resistance in the cable, and car is at operating temperature, you can take water and pour it on the top of the positive cable at the battery terminal. There will be a sizzle of water on the postive battery terminal when you pour water on it. If that doesn't work it doesn't mean its not bad still, a voltage drop will need to done from the postive terminal to where the cable ends at the alternator. I have really never seen a bad alternator on these cars. The misfires could be bad plugs or coils,and or both, but i wouldn't suspect the ECM.

 

You need a new CABLE, not terminal. It's the CABLE thats bad. I saw you had the terminal replaced.