I have this 2006 R50 which had a mysterious wire going from the footwell fusebox to eventually the power steering pump connector. The small controller connector, not the big power feed one. The pump is working so no issue there.

Now I'm trying to unbodge this as I did an engine swap and got a new to me engine harnas with it. So I thought, great! If there was a broken wire in the old harnas, the new one surely fixes it. But it didn't and I am left clueless.

First the bodgy wire from fuseboard to the pump connector.



In the last photo you can see someone unplugged the green wire and put another yellow one in and crimped that green wire from the fuseboard to it.

Here is what I got so far.

I found these two wiring diagrams:

The first one shows the pump on the left, looking at the bodge they took a live 12v feed from the fuseboard, cut the green wire near the pump and crimped it on there. I checked and this bodge wire is only hot when ignition is on or engine is running.

Now with the new harnas in the car I checked and yellow is getting 14v when engine is on. The green one doesn't has any voltage. Which is obviously my issue. So this brings me to the next diagram.


The green wire from the first diagram is apparently fed by the alternator. So I shifted my attention to that. So I thought, let's measure the voltage of the green wire coming from the alternator plug. That one is very accessible, as it clipped in onto the engine mount. Now this is what really makes me confused: on the back of the alternator are two pins, but the connector on the engine mount has three?

Sounds weird? Well inside the connector there are only 2 pins but it looks like there could be a third? Great so one oin snapped? Since I have two wiring harnesses I double checked and both have two pins, for three wires. Here is a picture of the situation:


As I test I thought, lets start the car with the alternator connector disconnected, I thought it would show the battery now charging icon on the dash but it didn't?

Has anyone got any suggestions on what I could test and check before I go and pull the footwell fuseboard?

 

i see green in the photos but on the diagram its grn/wht. am i seeing the photos correctly?

 

Yeah, assuming the documentation you posted is correct, the Bosch and Valeo alternators only have two pins in that connector, while the R53 and Denso have three.

I figured out how all this worked at one point, but I’ve forgotten now. I think that fuse (F38 or F39) is actually labeled wrong in one of the two diagrams, and I also think it’s feeding voltage to the alternator instead of the other way around.

 

The original cut off wire, shown in the third photo, is actually green white. The "bodge" wire is full green and they crimped it onto another yellow wire and inserted it into the plug.

Interesting. I've gotten the diagrams from this forum but found it on other Mini forums as well.

I've looked at pictures of the lower footwell fusebox and it's not looking fun to get it out. There are a lot connectors going into it so I can only assume it has no room for movement whatsoever.

 

Yeah, I have a copy of the whole pdf of this from the TIS. I think the F38 label is a typo, and it should be F39 (at least in the US). I don’t think F38 is even populated (see here). You can tell something is off because those two different diagrams with different fuse numbers call out the same connector number (X10207) and pin number (7).

From your descriptions (assuming I’ve understood them correctly because your seemingly interchangeable use of green and green/white is confusing), I would guess that there’s a break in the green/white wire somewhere on the pump side of the junction where it splits off to run to the alternator. Or if I’ve misunderstood, the break could be on the other side. I’m having trouble visualizing where you’ve checked voltage. Is fuse F39 good?

 

Yes you are right, I'm having difficulties explaining my situation because I'm not that good with electrical issues and me being non native English speaking doesn't help.

My findings so far:

• Both fuse 38 and 39 are good
• I have 12v at the pump on the big connector (with engine off and on)
• I have 14v on the yellow wire with engine on
• I have 14v on the battery when engine is on (12v with engine off)
• I have nothing at the green/white wire (with engine off and on)

I think I need to trace the green/white wire and see where it ends. Then I can do a continuity test to see if that wire is broken.

What I don't understand right now is how that green/white wire is coming into the fusebox at the drivers footwell. The engine harnes clips into the ecu and the fusebox in the enginebay, so it must exit one of those at some point.

Thanks for the help so far.

 

if the plug is 2 prong, and the pump is 3, is the pump from a r53?

maybe the additional green wire would not be needed with the right pump?

i'm not sure thats helpful

 

I found the reason of the bodge and was able to fix it. It's all using the original wiring loom now.

As I had the old wiring harness from the old engine I decided to following the green/white wire to see where it goes. Basically it goes from the big round connector at the front left of the engine bay to that plastic box section where your injector plugs are. There it's spliced to the alternator and power steering pump. While I looking at it I noticed the wire was damaged and broken:


Ok great! I at least found out why someone routed a new wire to the power steering pump.

As I now knew the route of the green/white wire I got back to the car and could check for continuity. Between the green/white at the alternator, power steering pump and the big round connector side.

It turned out there was continuity between all of them so I knew these were not the issue.

So I shifted to the fusebox at the drivers footwell. After digging it out I found the bodge wire and the original green/white wire, at the pink plug:




As you can tell, someone had de-pinned the green/white from the pink connector and pinned that new bodge wire into it. After unraffeling the tape I found the de-pinned green/white wire to be intact. So I checked it for continuity to that big round connector and it was fine. So I de-pinned the bodge wire, pinned the original green/white back in and sure enough, everything worked as it should be!

To be fair, someone did put effort into it making it look not bodgy. If only they had looked for where the wire had broken.

Now a few things that are very confusing or just straight up wrong in the circuit diagrams:

• Fuse 39 has nothing to do with it
• Green/white at the alternator side is just a blank. The alternator does not send a signal on it as it isn't even connected!
• Green/white is fed by the fusebox, not the alternator

Kudos to @deepgrey and @ssoliman for sharing your insights

 

good detective work! feels good when you final find it

blank at the alternator. VERY strange

 

Glad you got it figured out (and your English is fine—sorry, I think I was just being a tired, grumpy engineer about some of the descriptions).

From what I’m seeing online, it looks like fuses 38 and 39 are different between pre/post facelift. Maybe the two diagrams are for two different years? Mini changed the fuse panels between the two, so I could see them having the same pin on the connector potentially go to a different fuse.

My 2006 also appears to have those circuits on 38.

Interesting that it’s the green/white that is a no-connect at the alternator instead of the white.

 

Thank you! Indeed, it feels good.

Ding ding ding, you are the winner. Look at what I found hidden within a YouTube video from "fusebox diagrams":

Seems like they changed the fusebox in 2005 and the power steering pump fuse shifted position.

Hopefully this thread will help the next person who is having issues.