I've been having issues with my tachometer and various other things for a few weeks now. Tracking the issue down has become a headache to say the least. At present I have no tach,I have what seems to be no power to the tach at all ( no lights, no computer, no signals and no readings ) Speedometer works fine as does gas and temp. No lights on the speedometer when head lamps are turned on. Gas light works. Every start of the car shows -99999999 on the service millage and the trip millage resets to zero. Battery has gone dry twice as though the system has power somewhere when turned off. Though this was during a very cold few days here and batteries tend to drain in the cold if it gets too rough for them. Could be an unrelated issue Check list of what has been done personally: fuses are fine BCU connections seem fine. Topped with dielectric just in case. LH grounds are fine but not related to instrument cluster. Checked as I had that panel off to check BCU Tach connection seemed fine. Dielectric added as well to ensure connection. The only thing I haven't done yet is to check the RH sill grounds e9 and e5 as these seem to be for the instrument clusters. The real question is; will the grounds effect the computer somehow and cause the resets each time the car is powered. It is worth noting that water DID get into the car at one point due to a sudden flash storm and me being brilliant and leaving the sunroof open for a few minutes before I could get to it. When checking the BCU, it itself didn't seem wet but was given a chance to dry regardless over 24 hours. The area around it was wet under the insulation. This was dried as well and all wiring around the area checked for corrosion along with the grounds. I'm holding out that it's an issue with either the grounds connected to the instrument clusters at the body level or even the connections at the interior fuse box. Thoughts? Experiences?
After two failures I had it replaced under the warranty. It was only around 8 months old which is why I found it suspect of being drained rather than just being bad cells.
There are detailed instruction how to reset the ECU somewhere here on MA but i couldn't find it. Hopefully someone else will give you the link. It's fairly simple actually but i can't remember how i did it.
'03 R50 As an Update. Seems the battery is being drained due to something still remaining powered. A less than week old battery just had issues turning over the engine today. I'm going to stick the volt meter to it and pull fuses until the charge dies cluing me into what is still powered when the key is removed.
seeing as I have reset the ECU a billion times How to Reset the ECU: With the key in the ignition, but in the off position, press and hold down the odometer reset button with one hand. While holding the button down, switch the key in the ignition to position 1 (first click) with the other hand. The screen will have a number and the word “tEStâ€. Scroll through the numbers by pressing the odometer rest button, through to 19 and wait a moment. (Note: the number order is: 1,2,10,19) The message will say 19 "L i-off", flash to "L i-on", and back to "L i-off" again. When "log i-off" appears, press the odometer rest button again. You are now in the system. Scroll through to 21. tESt and wait a moment. 21.0 rESEt will come up. Press the button once. Your gauges will now make some sounds and movements. Once the lights come back on start your car. You have now reset your ECU and your MINI is now ready to relearn the new mods and your driving style. I had something similar. I pulled out the plug out of the back of the tacho and speedo then refitted and all was fine. Also the grounds on my Mini were all bad due to a water leak.
While the instructions worked, nothing changed. I did however learn that it looks like the cars ECU is resetting each time the key is turned as it did the exact same actions as it has been doing once given the command. "-9999999 0.0 trip millage and all needles shaking with a buzz" :mad2: Fingers crossed that it IS a ground issue.
Worth looking at before I go pulling more trim off and taking the seat out once more. Given the amount of rain we had before the issue came up that's not a bad leap in judgement. ( Actual minor flood worthy ) Thanks for all the help. Have I told you all that you're awesome?
Looks like the connections are a bit gunky at that left front engine compartment ground you mentioned next to the air box ( now a cone filter ). I'm going to split the wires back and see if it managed to eat it's way down into them. This same connection is also for the interior fuse box (According to my Haynes manual ) which could also explain the way things sort of systematically shut down if the corrosion was eating up the wiring. We'll see.
Another thing noted that I didn't even think was related. Before everything went to hell with the interior lighting and tac I had a very strange "overheat". During a rain storm ( It rained for around a month straight during all of this :incazzato: ) I had a very sudden over heat according to the temp gauge. I was lucky and very close to a Quick Trip Gas station. Pulled in and let it cool before taking a look. I found the reservoir was a bit low but not empty. I picked up some 50/50 on the cheap and topped it. Looked in the access line and it was still full of coolant. This was a one time thing. Never did it again. I believe this is related because as an experiment I disconnected the above mentioned grounds (E2) and gave it power to see exactly what these grounds controlled in the interior/ECU first hand. I got an instant overheat reading as the ground for the sensor was no longer connected. Fans tripped on and the needle stayed vertical for around 30 minutes even without power and the grounds back in place. Much like the random "overheat" I had. Between that finding and a bit of the gunky stuff; it seems that with this I can confirm it's more than likely a ground issue at that source. Now my big choice is learning to do wiring on the fly or just taking it to the local mini shop and having them give it a go. Could be a relatively cheap fix if a tech can confirm a ground issue as well. A little cutting and splicing~ I'm mechanically savvy but wiring is a different beast to me. :crazy: