Right i`ll be first to admit when it comes to electrics..i`m crap! Park my 300tdi auto for more than a few hours and it needs a jump start. Alternator fine,battery a couple of days old and re-checked to make sure not faulty. This all began in the cold weather, not good when i need to be on the go at 5am.Anyone point at a common prob? The only possible clue i can think of is the immobiliser seems to act slightly differently lately when unlocking the drivers door,but this may have nothing to do with it.Anyone?? cheers mucky`un.
battery keeps draining
- Thread starter mucky`un
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summat is draining yo battery?
storm99
Spreading Joy & Harmony
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Yep...interior light/boot light/radio/microwave/cuddly toy?
blue beasty
Leaks an prone to bits dropping off
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such clarity of vision.......such understanding of complex issues.....and once again MHM goes start to the heart of the problem.....awesome
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My concern wud be - if it drains a (70Ah) battery in "a few hours" thats like taking 35amps - 420watts - that's one hell of an interior light .
Maybe yu need to be a bit more precise in your battery capacity and time from charged to flat.
.Maybe yu need to be a bit more precise in your battery capacity and time from charged to flat.
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airhook
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Don't know if this helps, I had a weird voltage drain on my TD5.
New battery went flat in hours. Got the local auto-electrician in & he confirmed I had a 10 amp drain. We started going thru the system & were coming up baffled. Then we disconnected the big wire from the alternator & the drain went away, re-connected & it was gone!
Neither of us knows WTFH, but it's been OK for a year now.
Might be worth a try.
New battery went flat in hours. Got the local auto-electrician in & he confirmed I had a 10 amp drain. We started going thru the system & were coming up baffled. Then we disconnected the big wire from the alternator & the drain went away, re-connected & it was gone!
Neither of us knows WTFH, but it's been OK for a year now.
Might be worth a try.
Thanks for all your ideas guys,will try all these tomorrow and any others you may come up with..cant keep nickin` wifes corsa! I feel sure there`s many a 300 owner before me who have had the same story,or maybe its not a 300 thing but a disco thing....
david collings
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Hi, over a 5-7 day period my discovery ii kept going flat, it turned out to be a faulty split charge relay for the 12's' two bar socket, some fool had placed it diectly below the sunroof water discharge pipe loacted behind the o/s/r light unit, over time the relay had filled up with water and was no longer switching, thus in turn running the battery down
addicted2welding
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You say alternator fine , how was it tested ? Reason for asking is that I had same problem and it turned out to be a fault with a diode in the rectifier circuit of the alternator .
just had the same or similar problem; my battery was dragging down (dead flat) within 20 minutes of stopping. At this rate of discharge I would have expected to smell smoke if not see a fire, but no such thing. Glow plugs draw enormous current
A bit of advice from other members pointed me towards the heater plug relay and in my case it was good call. It seems to be the timer side of the relay that's gone tits up. The heater relay is situated just behind the engine bay fuse box, front right. Try disconnecting it when you stop and reconnecting it when you want start the engine
A bit of advice from other members pointed me towards the heater plug relay and in my case it was good call. It seems to be the timer side of the relay that's gone tits up. The heater relay is situated just behind the engine bay fuse box, front right. Try disconnecting it when you stop and reconnecting it when you want start the engine
With reference to the alternator test,the guys at the exhaust/battery centre did it while rechecking the new battery.They did some sort of discharge/load/recharge test on it,using some space-age bit of kit that i`ve not seen before.cheers for taking an interest...
Letsgodisco
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Had the same problem last year with my 300tdi (manual).
Battery going flat in a few hours but not all the time. Sometimes it was ok for days.
The bottom line was a faulty glow plug RELAY, the spring inside had gone weak. I found it eventually by connecting a 12V LED onto the glow plug link cables (on the head) and blu tacking the LED onto the dash.
I noticed that the slightest bump in the road made the Led flash - sometimes it would stay on for a mile or so, on the speed bumps it was a proper Disco.
Just slamming the door made it come on and stay on - this was enough to drain the battery in a couple of hours.
I had a secondhand relay - which turned out to have the same fault!
In the end I pulled out the relay and ran without glow plugs, no probs even in sub zero temperatures, just a bit lumpy when first started. My other disco had four plugs that didn't work and a duff head gasket. It still started everytime in snow, ice etc.
A simple test would be to pull out the glow plug relay (under bonnet) and see if the battery hold its charge.
If the alternator is causing drain in a short time it will usually be hot or very warm to the touch when the engine is stone cold, easy to spot at this time of the year.
Hope this helps, good luck!
Battery going flat in a few hours but not all the time. Sometimes it was ok for days.
The bottom line was a faulty glow plug RELAY, the spring inside had gone weak. I found it eventually by connecting a 12V LED onto the glow plug link cables (on the head) and blu tacking the LED onto the dash.
I noticed that the slightest bump in the road made the Led flash - sometimes it would stay on for a mile or so, on the speed bumps it was a proper Disco.
Just slamming the door made it come on and stay on - this was enough to drain the battery in a couple of hours.
I had a secondhand relay - which turned out to have the same fault!
In the end I pulled out the relay and ran without glow plugs, no probs even in sub zero temperatures, just a bit lumpy when first started. My other disco had four plugs that didn't work and a duff head gasket. It still started everytime in snow, ice etc.
A simple test would be to pull out the glow plug relay (under bonnet) and see if the battery hold its charge.
If the alternator is causing drain in a short time it will usually be hot or very warm to the touch when the engine is stone cold, easy to spot at this time of the year.
Hope this helps, good luck!
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