Greetings electrical guru's.

I was one of the racers in the first MiniChallenge event. When it came time to start the car for the race it was dead. no power anywhere. so it's time to diagnose what is wrong.

here is what I have found so far.
- power at the battery 13V
- power and continuity across the 200 amp fuse in the battery box
- power to emergency cutoff switch on cowl
- switch functions, switch off - power only on input side, switch on - power on both sides of switch
- power at starter
- power at fuse box in engine bay
- no fuses blown, even removed the fuse box and checked the fuses underneath

No power to the interior. no lights on when doors open. no power when key inserted and turned. no radio, no fuel guage, no clicks, no whirs. totally dead.

No fuses blown in fuse panel in drivers left panel.

i had thought that the anti-theft might be an issue, but that does not explain the lack of door lights when the door is opened.

03 MCS, mostly stock

suggestions, tips, comments?

TIA

 

It's under the passenger side kick panal. See if power gets there, but doesn't come out!

Also, you might want to see if you're getting power to some of the fuses in the driver side footwell.

Also, some of the realys might be dead, The main relay is the front most one in the engine compartment by where the wires come in. You might want to try bypassing that and see if things come back to life....

Matt

 

Thanks

I will try those options this afternoon.

I am leaning away from the anti-theft/immobilizer as it does not explain the lack of power to the door lights. and the passenger foot well location is now somewhat hidden behind the cage.

I'll check the power to the inside fuse panel

And I'll check the relays. Is ther a fool proof manner to check them rather than just replacing with new?

keep the ideas coming

 

No dash lights? No lights of any kind?

There's some sort of "emergency limp mode" in the BC1 - can't remember exactly what it is but I think its meant to give you at least some lighting even if the BC1 is dead.
Try the parking lights and flashers - if they did work but nothing else, that might be a BC1 issue.

However I don't think the BC1 would prevent you from starting the engine.

 

Since power is everywhere it should be but there is nothing functioning, I would tend to believe there is something going on with the BC1 module and ECU as well, since these are responsible for activating and controlling most subsystems. The only exterior light not controlled via the BC1 is the reverse light.

The MCS electrical system is dual-path from the battery, with the starter and alternator having a direct feed from the battery via the under-car cable, and everything else via the fused (250A) internally routed cable. Not sure here, but if the main feed is disconnected while the starter feed is still intact, this could result in a 'shutdown' condition sensed by the electronics. As a guess, try disconnecting the battery ground terminal for a few minutes then reconnecting it making sure the cutoff switch is in the on position. This will apply power simultaneously through both systems and not be sensed as a fault.

I cant recall anything in the wiring diagrams that show too much interrelated with both wiring paths, but still it's worth a shot.

 

You can check resistance of the relay coils, and check if there's voltage where the relay goes.

I think there's a separate line after the 200amp fuse that powers all the body stuff. Might want to check that

 

If you know the in/out pins. Just make a jumper, put it in, and see if it comes back to life....

Matt

 

It was definitely worth the shot. This cured the problem. At various stages during the diagnostics we had had one or the other battery cable off, but never both.

Initially I tried to see if any electrical worked - but no hazards, no reverse light. The relays checked out fine, and the drivers fuse panel had power at the fuses I checked.

So last resort was to remove both battery cables, wait 5 minutes and reconnect. Bingo. lights, action, running Mini, happy owner.

Thanks for the advice guys.

Would there be any way to track the codes to see what caused the initial fault? (so we can avoid doing the same thing again)
or have the codes been cleared by disconnecting the battery?
and I assume the disconnect also reset the OBC so it needs to learn the driving parameters again.

I don't want this happening before a race again.

Thanks for the tips and suggestions.

Bones

 

Wierd.
But I don't believe the "both battery terminals" was the cure - perhaps this time you waited a really long time and that cleared the problem; or perhaps you just got lucky this last time.

Either way, sadly, it might happen again. I read of people saying disconnect battery to clear codes, so presumably there are no codes left now to give you any clue.

 

Disconnecting the battery doesn't clear any codes. But it is possible that this fault didn't set any codes. Sometimes electrical issues doesn't set any faults and can be remedied by removing power or ground and reconnecting.

There was a BMW at school, airbag problem and I knew what controlled it, but module was fine etc. After checking pretty much everything I just pulled the relevant fuse and plugged it back in and it worked. No idea why, just happens :\

 

I see a similar issue. When I went to start my car all electricals went dead. I tried to jump-start, the internal lights came on but my car refused to start. After several attempts I gave up and started to lock the car, my anti-theft alarm was getting triggered. I somehow managed to stop the alarm and let the car be for the day. Next day I got my spare to start and the car started like normal as if it never had any problem. I used my car all day and it was perfectly fine. Next day, when i started it again, it behaved exactly as it had with my original key and all the electricals went dead on me. Now I have 2 keys and none of them are working. Can anyone help me ? What is the problem here ,ideas, suggestions, etc ...?

 

Loose battery connections?

 

You may have a faulty (not blown) ACC (its like a master fuse for most interior power) fuse under the hood. Not sure of the number. My friend and I blew one on his accord the other day while installing new lights. He crossed a few to many wires and it blew. We were worried when none of the interior electrical worked but the fuses were fine. So with some searching, some guy with a subaru did the same thing. Its just a square fuse that blew, go figure. Hope this helps, a $2 fuse is a bit cheaper than an $800 BC1. I just had to get mine replaced because of some water leak
Good luck