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I have had a problem with the battery draining after standing for a few days. Purchased a clip on ammeter which I clipped round the negative battery lead and measuring approx. 1.5 Amp drain.
I had a problem with the ignition switch in that the gear selected led indication never went out when the ignition key was withdrawn. Changed the electrical part of the switch and this cured that problem and battery drain now dropped to 1 Amp. My radio is faulty and will not power up. Removed the fuse in the fuse box and the drain dropped to 0.5A. So radio fuse left out.
Withdrew fuse B4 which supplies the engine compartment blower fan and the current dropped to a few milliamps which is normal. The blower is working properly and relay 8 in the rear boot is being energised by the DME when the temperature rises so I am only leaving fuse B4 in when driving. If I remove relay 8 there is still 0.5A battery drain so looks like a wiring fault somewhere. The 12V feed from fuse B4 goes through a connector X2/1 pin 11 before going to the relay socket in the rear boot. Anyone know where this connector is located as the problem might be there?
If you have any suggests they will be most welcome.
Mine was draining the battery in a few days while parked. A member on here said to lock the door with key fob, and let it set the alarm and it turns everything else off. When I started doing that it will hold for weeks. But I always unlatch the front hood when parking in garage just in case I need to get to battery.
Using the key fob, just passing along information, and it worked for me. If I don't lock with fob, battery will be down in a few days, But if I use the key fob it can set for weeks. Just know there is less drain that way.
Hi thanks for the reply but my alarm and remote locking are not working. The only way I can lock both doors is to operate the lock switch on the dashboard then get out of the car and lock the drivers door with the key. With the 2 fuses removed as mentioned in my first post the drain is only a few milliamps. Just need to get the bottom of why the engine compartment fan circuit is drawing 0.5A with the car standing and locked.
Decided that tracking down the cable fault was too difficult so located a spare fuse A6 Which is only live with the ignition on. Removed fuse B4 (ENGINE COMPARTMENT FAN SUPPLY) and linked A6 to fuse B4 output.
This now means that with the ignition switched off and the key removed there is no power feed to the engine compartment fan hence no battery drain whilst parked up. With the ignition on there will be power feeding the fan relay contact so cooling will take place when demanded whilst the engine is running.
Electrical problems have been numerous on my car but its not surprising as it stood outside in all weather for 7 years and was never started and of course the drains were blocked and it was running with moisture.
Probably difficult to do at home but the fan itself may be more inclined to build resistance than the connector you are referring to. It may just be old and tired and drawing a load on the battery. It may work just fine but never actually "sleeps"
Thanks for the comment but the drain occurs even with the fan relay unplugged from the socket so at a loss to how the battery drain occurs since I have connected a meter in series with the compartment fan fuse and there is no current being drawn through the fuse but somehow it is enabling another circuit to drain the battery. I have posted my work around solution for now which is doing the trick the only drawback being that the fan will not start with the ignition off and the car standing with a hot engine after a run.
Thanks for checking but I have a copy of the circuit which is frustrating because being an electrical engineer there appears to be no logical explanation to the fault. But I know that there is always a logical explanation. I have a couple more electrical faults which have developed which appear to disprove basic electrical theory. I will post them later. One in particular relates to the alarm siren but I will carry out more checks before posting. I think that I have one basic fault somewhere affecting several circuits.
changed the alternator, both sun visors, infra red passenger sensor, heated mirror relay. wing mirror adjust switch, soft top control relay, intermittent wiper relay, ignition switch, air con interior temp sensor, accel pedal potentiometer and throttle body to get to this stage.(all faulty)
06-18-2019, 09:46 AM
Boxster 2001 986 S battery drain
