QuestionHello there John
I hope you can help me, I purchased Betty my 1994 LR disco (2.5 TDI) around 2 months ago, knowing shes in need of some tlc, for around 3 weeks she started up 1st time every time and had minimal problems (after a good service and all fluids topping up!) as the battery had been disconnected the radio was asking for the code which ended up with me leaving the radio on all night thus draining the battery - we jump started her and she fired up and ran well all that day (car was used off and on throughout the day and started up no problems) then each morning when i come to start her since then the battery is dead as a dodo!!!!! i went and has the battery checked at 2 garages and they both sAID the battery wasnt at fault and that something was draining the battery over night but they couldnt figure out what - the rear sunroof motor was hot and that had jammed in the pas so we disconnected it to rule that out but to no avail - she not the easiest car to push so i am hoping you have an idea!!!!
many thanks in advance
Natalie!
AnswerHi Natalie,
it's possible that something is draining the battery. It's also possible that the battery is unable to hold a charge OR the alternator is not recharging the battery.
You can try finding the short by selecting various components and pulling the fuse overnight. Much like the overheating sunroof motor, you would have to pull the fuse and see the result the next morning.
In my case, I had trouble with my Air Conditioning compressor and did not know it. Like you, I could not start the vehicle the next day. In order to find the fault, I pulled three fuses (AC, starter motor, radio/windows) and lo and behold, my '95 Disco started the next morning. Having narrowed it down, I began the next test with the starter motor. Next day, Disco would not start. I replaced the starter fuse, and pulled the AC fuse that night. Next day, Disco started. To verify this, I reinstalled the AC fuse, and that night I pulled the radio/window fuse. Next day, no start. Thus, I had found that my AC was shorting out and draining the battery. I pulled the AC fuse (it was winter) and replaced the compressor that spring. Seems there is a switch inside the compressor that can shortout.
I also have had my fair share of battery troubles on my '95 Disco. I have found that if my battery ever goes dead, the alternator has a hard time recharging it. Not only that, but I have had to replace too many alternators as a result of batteries going dead. Was it a bad alt that caused the battery to die or a bad battery causing the alt to burn out? In my experience, I found that if I fully recharge the battery using a battery recharger, it has a greater chance of lasting longer. IF I do not, I feel that the alternator is unable to recharge the battery AND it can even damage the alternator. I've gone thru 3 alt's and concluded it's cheaper to replace the battery and save the alternator. Common battery faults result from cell failure and this is very hard to detect. Sometimes even load tests don't reveal a damaged cell problem. A good shop will have other tests they can perform to verify the state of the battery.
If you go to Advance auto, PEP Boys or Auto Value, most shops will perform a battery or alternator test for free. Load testing should be performed and sometimes even a conductance test will have to be done to test the cells.
SO...have your alt checked to be sure its recharging your battery properly. Go to the dealer and request the radio code - they'll do this for free (unless they are scumbags) and you can register yourself as the new owner (good for recalls).
If you suspect a component is shorted and draining your battery, pull out three fuses at a time and wait overnight to see if it starts. I'd go with fuses for radio (#1), AC (#15) and starter (#17). If it does not start, try mult-function unit, central door lock and sunroof.
That's if you suspect a shortage.
Hope this is useful,
JohnMc
