1st Gen R53 Cooper S Brake lights and dash on, keys out

Happy New Year!

I'm new here and hopeful one of you have the answer I'm looking for.

My Mini suddenly has an electrical gremlin.

Coming out to my 2002 r53 to go home after work yesterday, I saw my brake lights were on. The dash lights were also on as if the key were in and turned on (position 2, I guess). The lights were switched off and the keys were in my pocket.

It sat that way long enough during the day to keep it from starting.

It seemed to be fixed temporarily when I got a jump start, pulled the ignition fuse, turned the key on, then replaced the fuse. I'm not sure if the boost or the other action was the key ingredient or what.

Today, the dash lights and brake lights came back on while sitting parked since last night. The battery is now too low to turn the starter over. I've left the battery disconnected for now.

I should also mention I had the fuel pump replaced a couple of weeks ago. The plastic end had split and it was spraying half the fuel out.

My thoughts point to the ignition switch, moisture in the bc1, or just a low battery. I pulled back the trim panel to look at the bc1 today, but didn't take it out. It seemed pretty dry down there, but the rubber door seal did have some moisture under it. The Mini has sat in some heavy rain the past couple of weeks, but not driven in it.

If anyone can point me in a direction, or rule out anything at all, I would really appreciate it.

 

It has a Duralast Gold in it that's been there since I got it a few years back. It probably needs replacing now that I've considered that time frame.

I'll post back tomorrow night or Saturday with an update.

 

Update!

I had a crank-no-start situation Friday. The crank sounded strong. Took the battery to the local auto part store. The guy said it looked like it ought to be strong enough. Up to now I was convinced it was the battery since the dash and brake lights went off after charging it a bit.

The spark plugs looked OK. I didn't actually check the spark because the next day the battery was completely flat.

I also found the driver-side (left) floor to be soaked with water. I think this went unnoticed for quite a while since it was under rubber mats.

The carpet was soaked only on the flat bottom. I couldn't find any dampness behind the pedals or near the door. Passenger side appeared dry.

Pouring water in the sunroof drains was inconclusive. It seemed to be draining fine, but i don't know. So my next step will be to pull back the roof liner to look at the hose in there.

But I really think it might be the A pillar gasket. That exterior trim piece doesn't look like it was put on very well.

I'll post a pic if it's light enough when I get home.

Should I go ahead and get another battery, or just charge this one one up to continue the diagnosis?


Thanks to everyone for the tips.

 

I did a load test after charging the battery back up. It only dropped to about 11.3V while turning it over. 12.76V with the key off, and about 13.1V before I reconnected it to the car after charging.

I noticed a sticker on the battery that said "4/12" which I guess is its birth date. It seems fine for now.

I also put my multimeter to the spark plugs and couldn't get a reading on two of them because the tip was burned down past the insulation. On the 20K Ohm setting, I got a reading of about 16 on one and 3 on the other. So I'll buy a new set of plugs.

However, I don't think this is the source of the mysterious brake and dash light situation. I left the freshly charged battery on it, I'll see If they're on tomorrow. I'll also check the battery level.

 

What is a proper load test then? Is it any more than measuring the voltage drop while turning it over for about 20 seconds? I have googled it, but that's all I came up with.

I do realize the battery is at the end of its expected life, but I would like to test it properly.