Hello, dropped my son off at school this morning. Pulled out of the school and as I went the windshield wiper/fluid light came on, then 5 seconds later my check engine light came and the car started to bog down. I hit the throttle and the lights went off and I continued driving to work--about a mile and a half. When I parked--put the car in park--I sat with the engine idling for a minute. The windscreen fluid / wiper light came on, then the check engine, quickly followed by the battery light, then the car stalled. I cranked her and she started right up with no dash lights indicated. At lunch I drove home with no problems. I took the truck back to work. After work I checked my battery connections and in general looked at most of the electrical connections and grounds I could see (mostly in the trunk). I also put a volt meter to the battery. With the ignition off--12.5, with the car running 14.3. Does this sound familiar to anyone. Electrics are my weakness. I will tear into anything mechanical, but electronics leave me scratching my head. Jag is the car for me right? I love this car--electronics or not. Any ideas where I should start? I might take it to work tomorrow to just see what happens--though I don't feel like paying for a tow! HELP!!!!!! 1995 X300 Scott

 

Anyones guess is as good as mine--------I might have to buy one of the OBDII code readers today. could be a coil, ecm, I don't think a dirty throttle body would cause this--has to be electrical

 

First have the battery load tested at your local autoparts store. If the battery checks out start looking for a loose or corroded earth strap in the engine compartment.

 

I thought with the voltmeter readings that the battery checked out ok, but your right it could still be a bad battery. I also noticed yesterday that when I turn on my headlights they flicker if you tap on the headlight switch, so this morning my lightbulb out light on the dash was lit up, but I checked all the turn signals, brake lights..etc, and they all worked. I am going to remove the switch this weekend and clean it up, maybe that will help. I will probably buy a scanner today if I can find the right one. I read the sticky, but it is still not clear. Anyone have suggestions in that department? Thanks----Scott

 

The thing with the Jag batteries is you NEED them to be at 100%. Period. When I first bought mine I plugged in my iPhone trying to charge it (there was a short in the cigarette lighter thingie) and it killed my battery. Took it to Auto Zone and when they checked it it was at 97% (sounds good to me) but talking to a few different Jag mechs they all said with all the electrical stuff in there you need:
A: A HUGE battery capable of running/holding that much stuff (something along the lines of 950+ cold starting amps)
B: A battery that is pretty much always 100%

I have come to the conclusion that Jags are some of the smartest built cars because when they fail, they fail on a smaller scale so as to not hurt any of the larger components. Granted even those small components cost us an arm and a leg....

 

i would agree do a load test on the battery and check all known grounds.
Danny

 

Check the power connections on the firewall . They are the ones with the big wires that look like small hoses going to them up high towards the outside on both side of the firewall. Disconnect the battery first, then check them for corrosion and tightness.

 

thanks for all the input. in the morning I will pull the battery and take it in for a load test. While I have it out I will check everything at the firewall. After work today I checked the battery again out of curiosity. Car off 12.5, car on 14.39, car with headlights--A/C and radio on 14.25. don;t know that says anything. being a shadetree ex-army mechanic I always thought that was a way to test load. I will be at autozone in the AM bright and early. Thanks---have beer on me.

 

Well I took the battery in and the battery charge was at 93% the guy said it passed the load test and we put it on the charger for about 30 minutes and it went up to 100% I almost bought a new battery--they have a duralast which has a 1000 amps and I think it would fit by moving the bracket back. Do you guys think 93% is acceptable? I also opened my headlight switch housing and cleaned all the contacts. Didn't pull it out because of the circuit board being in the way, but I cleaned it in place. Headlights still flicker if you tap on the switch--might need a new one, haven't seen any online--any one have any leads? Let me know what you think about the battery. I am going to get (hopefully) OBDII scanner today--going to look at sears. By the way the car starts and runs great and the lightbulb dash warning light went out, though that could be because I disconnected the battery---it did not come on after I cleaned the switch and started the car. I'm going to take her for a spin and see if she stalls---if I don't make it back save me a beer--------Scott

 

93% is not high enough to run a Jag. My old battery was at 97% and my jag would stall when I dropped below 2k rpm. I had to shift into neutral and rev the engine until the light changed. If it continues to happen you really should look into another battery.

 

alright Roadhouse, took your advice and bought a new battery. 1000 cranking amps----850 cold--of which we hardly get here. Took her out for a 35 <> mile run, a few stops at stores and no problems. Hope that was the cause of the stall. No dash lights. I am thankful for your help. She is a great car to drive.

 

I am not sure what "98 or 97%" means on a battery, but there is an anomoly that was reported years ago that with X300s, on certain cars with presumably bad filter caps in the ecu, could have ecu glitches due to low battery charge. It is certainly NOT universal.