2004 MINI Cooper
Mileage
55,214
Service Date
8/24/2023
Services Performed
- We inspected and found that the battery was below 11 volts. We jump started the engine and noticed that the starter motor turns slower than normal which likely indicates that the starter motor bearings and brushes/armature and worn. We checked the charging system – OK. We sent the car to sleep and found that there was roughly a 150 millamp draw. >>Need additional time to diagnose the cause of the battery drain.
- We charged the battery and set the car up for a battery drain diagnosis. We found a 140-160 millamp draw. We used an amp hound to check all testable fuses and found fuse F4 with a 70 milliamp draw. Wiring diagrams show that this fuse only supplies the Body Basic/General module. We removed the fuse but the draw did not go away. We disassembled the air filter housing to access the maxi fuse panel and engine compartment fuse panels. We found that the air filter was black with dirt and grime. We traced the power going into the maxi fuse panel. We did not find any fuses with a draw with the amp hound. We used an amp clamp and identified a red/yellow wire with 80 milliamps. We traced the wire back to connector X4009. The wiring diagrams indicate that this is another large battery power wire for the General module. >>We suspect that there may be an internal issue with the General module. This small of an amp draw would usually take a few weeks to cause a battery to drain to the point of not being able to crank the engine. This draw has repeatedly depleted the battery little by little to the point to where the battery is aged and should be replace. A new battery will treat the symptom but will need replacing again before its normal interval. >>The general module is no longer available and replacing with a used module is not an option due to the VIN being written into the module. >>Need to access the general module and manually test each wire for amperage in order to determine if the issue is the module or one of the circuits fed by the module. There are about 100 wires to test. Our conversation with the client turned up an issue with the alarm going off randomly. We removed the alarm siren and disconnected it and reinstalled it. When we went to retest the system for a draw we found that the battery voltage had fallen from 12.4 volts to 10.1 volts just a couple minutes later without us using any power. We tested the battery again and discovered a faulty cell. >>We replaced the battery under warranty, reset electrical systems and rechecked for a battery draw and found only 20 milliamps which indicates that the alarm siren is the cause of the draw.
- Found that the battery has an intermittent issue with one of the cells not working properly. The voltage would decrease suddenly by 1.2 volts which is consistent with one cell being faulty.
Baron D. gave our service a 5 star review on 8/24/2023
