Well its taken me nearly 4 months to sort this little B**stard out, mainly due to the fact that the fault only occurred once in a blue moon, normally when its dark, pissing down or in the early hours of the morning when your late for work.
The symptoms where that it will totally kill the battery in about half an hour when ever it felt like it, with the Car (Omega 2.5TD) switched off and locked up.
Having spent weeks disconnecting everything electrical one by one and waiting for the fault to appear, my last thoughts was on the Glow Plugs (glow plugs switching them selves on at 6am in the morning??).
Well managed to catch it this afternoon, while I was downing a Burger in the Car with the Radio on (not for long). So quickly rushed to the engine bay armed with my DVM and hey presto, 5 Volts feeding each glow plug (should have 12volts but the battery was already down to 5). Pulled the lead plug off the top of the GP relay and watched the battery slowly recover to about 10 volts.
Now thinking I’m probably not going to get one off these Relays before next week (BMW Part 72RB500), I decided to open the bugger and look inside, sure enough a small relay with twin contacts, one perfect the other totally pitted to the extent a large pyramid pit almost touching its target contact (see Pic’s).
If you take the small spring off the relay shutter you can actually lift the shutter enough to poke a small file in and resolve. I know this is not the answer but its going to get me out of trouble for a few days.
While I was there I measured each glow plug resistance, 0.8 ohms. The relay is fed unswitched directly from the Battery, so some simple maths 0.8 ohms across 12 volts = 15 Amps, x 6 for each plug, = 90 Amps !, permanently across your battery, certainly a Show Stopper.
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Topic: Whats Killing the Battery? 2.5TD (part 3) Gotcha ! (Read 1456 times)