P38A Is the battery defective?
- Thread starter Frank_38
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can you confirm your meter is accurate? check it against another battery, if you only have the one car battery, try a 1.5v AA (1.2v if its rechargeable)
i wouldnt expect to see a battery at 13v after sitting overnight
i wouldnt expect to see a battery at 13v after sitting overnight
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i would expect a good battery to be ~12.7v, a poor battery to be ~<12.5v after a nights rest.
you also need to measure the voltage while the engine is cranking.
if you leave the headlights on for 5 min do they start to go dim?
you also need to measure the voltage while the engine is cranking.
if you leave the headlights on for 5 min do they start to go dim?
Datatek
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As Kermit said, it's unusual for the battery to stay above 13 volts after standing overnight but not impossible off the car. The voltage will not give you any indication of the battery's capacity. When you say the car does not start, does it crank at a good speed?
Grrrrrr
Technician, Bodgit & Scarper Ltd
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Does it crank or click at all? Starter motor has a BIG fuse in the fusebox.
Datatek
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Really? On mine the feed for the motor is direct from the battery only the solenoid is fused.
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There could be a drain but have the battery capacity tested. 
Grrrrrr
Technician, Bodgit & Scarper Ltd
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Counting that as part of the same unit seeing as they're stuck together.
80A fuse on mine and it is shared by the EAS compressor which can seize and blow the fuse. Bloody stupid arrangement which they obviously realised because later models took the EAS compressor off into its own fuse.
RangeRoller dt
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I’m guessing that the OP has a doozle?
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Does it matter?
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...the battery is still in the garage.
Just tested 12.96V. I think the voltage is ok.
My charger shows me that the battery is still over 80% charged.
I'll fit it again on Saturday.
But that means that something in the car is continuously consuming power. Thank you!
Just tested 12.96V. I think the voltage is ok.
My charger shows me that the battery is still over 80% charged.
I'll fit it again on Saturday.
But that means that something in the car is continuously consuming power. Thank you!
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Bear in mind a 50% charge is considered dead flat for a regular car battery
Datatek
Well-Known Member
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Do the BECM sleep test.
Grrrrrr
Technician, Bodgit & Scarper Ltd
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- 19,772
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- Buckinghamshire, UK. ('95 DT)
Top candidates:
RF interference
After market stereo
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