This is my problem – my Jag would not start. At first I thought it was the battery because it was drained, so I jump the car and drove it to let the battery charge, but in about 10 minutes the car lost all power. I jumped it again and while driving it this time notice the battery starting to drain, and the above happened again.

I checked both wires going to the alternator and initially thought it was the wire going to the dash because it was not producing a spark, but a post here cleared up that problem. I did not think it was the alternator because I replaced in January. I was baffled, so I jumped it again and drove it to the nearest garage.

The garage (not who I usually deal with) thought it was the alternator so they sent it out to be rebuilt. Once they received the alternator back and installed it, the same problem was present. After further inspection by them, they too do not know the source of the problem.

Could somebody add any insight to the matter?

 

Any knowledgable members out there help with this one??

Sounds very similar to an issue I had with my sons Clio some time ago, turned out to be the crankshaft sensor (tdc sensor) and loom, once this was replaced it solved the problem.

Hope you get your issue rexolved real soon

 

"Lost all power"....Does this loss of power happen suddenly or does it sorta gradually occur over a a few minutes?

Have you chekced that battery cables, the "+" junction posts on the firewall, and the main ground?

post back for details if needed

Cheers
DD

 

Does the battery indicator on the dash light up? It is a critical part of the charging system. It is part of the circuit that triggers the alternator to charge.

Have you done any voltage checks when the car was running? I recommend getting the battery charged (some parts stores will do this free if you don't have a charger, best to get a nice little modern charger though-- like the C-Tek.

Once the battery is charged, connect the meter and it should stay at 12.6 volts or something close. Start the car, and the voltage will momentarily drop, but it should stay above 9.6v when cranking. If it goes below that, the battery is bad. Places like Wal-Mart or parts stores will also test the battery for free with a hand held tester or cart.

If the alternator is working right, the voltage will come back up above 12.6, and hang around 13.5 volts or so, depending on the battery state of charge, headlamps on, etc.

The trigger wire for the alternator comes from the indicator light, to the back of the alternator, and it should have voltage when you first turn the key on. To test it, disconnect the alternator, and connect the small wire to a test light. Ground the other end of the test light on the engine. Turn the key to the run position. Light should illuminate. If not, try moving the ground for the light to the negative battery post.

The fat cable on the alternator goes to a stud on the firewall, driver side. Then another cable goes from this stud over to a stud on the passenger side. The battery positive cable and the starter cable also connect to the stud on the passenger side. Make sure all these cables are secure and in good condition. If you are careful, you can bypass suspect portions of the cable with the positive side of a set of jumper cables. Be really careful, though, because it will spark big time if it grounds out. This is a lot easier with a helper to make sure nothing moves around when you try cranking it over.

Ground for the engine is very important to charging and starting, just as much as good battery cables are. The engine is grounded with a large braided cable that is under the passenger side of the car, between the engine and the frame. Take the cable off, clean the ends so the metal contact surfaces are shiny, use some dielectric grease to prevent oxidation, and reconnect the cable. Replace the cable if it is corroded. To test whether the cable is really working, you can use a jumper cable in its place and see if there is any difference. Connect the negative jumper cable between the battery negative post and the engine. Leave the positive cable disconnected on both ends.