Hey guys,

Recently my Rover started acting up (more so than usual), and I think I'm getting closer to figuring out the issue, however I'm now finding myself lost.

A few weeks ago, when driving with the windows down, I noticed a burning smell coming from the right side of the vehicle. Definitely electrical. Fortunately I wasn't far from home, and got it home, parked it.

I haven't driven the car since, but now I've noticed the battery draining out overnight. Pretty sure the battery is now toast, as I can jump it and run it awhile (no burning smell if just idling) and then the battery dies out pretty quickly afterwards.


Rather than ruin another battery, I jumped the truck, let it run for a bit to charge up the battery, and then shut it off, and hooked up a test light. Test light would pulse, about once every 2 seconds or so. Started pulling fuses and lo and behold, F13, the BCU is what's drawing. I don't have a multimeter, so I can't tell you how much, but I can say the test light was pulsing brightly until I pulled F13.

I know nothing about this BCU, or where I should even start looking for a short. I've been reading through the RAVE, and I did notice it's responsible in part for alarm/immobiliser function, so I'm also wondering if I'm barking up the wrong tree here, and some draw is normal. Can anyone help me out here?

 

A difficult one. The BCU controls a host of electronic functions and hard to isolate which is causing the grief. You would get some draw on the battery as the alarm system draws a pulsing current every few seconds. A pure guess is two things, one your alternator isn't charging the battery and two the battery is past it's 'sell by date' and probably not holding a charge. You need to get the battery checked to see whether it's scrap and also test, or have tested, the alternator. It's needs checking for voltage output and amperage output. Voltage can be done with a cheapo multimeter but amperage needs a serious bit of kit and best done by an auto electrician. DON'T try doing the amperage test yourself with a cheap multimeter as there will be a big flash and the multimeter will blow. Try borrowing another battery for your D2 which is in good condition and see whether it holds a charge (even if it's slightly smaller duty) and also have the alternator tested for output.

 

I'm thinking it's a shorted +12v wire that's grounding out intermittently. Possible fire hazard. I'd trace the wire that leaves that fuse for the BCU every inch of the way to the BCU. But be careful, you can damage other wires by being rough with the wiring harness.

I sorta halfway think I'd just cut the wire a few inches out of the fusebox and the BCU and jump it with a new wire. Then I'd check with the test light to see if it fixed the problem.

Good luck, this stuff can be a PITA.

 

Yeah, I had the idea to try to run a jump wire as a sort of temp fix, until I can figure out what's driving the short. My main concern with this was if the BCU was staying "awake" and the draw was normal or if this was an aberration. Sounds like it's the latter, from what I've heard so far. I'll run a jump wire and see how that works out for me. What sort of threw me for a loop is that nothing seems to be acting up, the truck operates as normal besides this issue. Thanks for the info so far, I'll update as I get further into this thing.

 

This was actually my first thought, was a bad alternator/battery, but the burning smell is what's got me thinking otherwise, more along the lines of a hot short melting something (initial visual inspect of the main harness to the fusebox looks ok, but of course I can't see the whole thing) Would a bad diode in the alternator burn up, or would it just drain the battery?

 

Did you ever resolve this FL13 parasitic draw? I have the same thing in my 2001 D2. An ammeter across FL13 fuse shows about a 700 milliamp draw when everything has been off. I'm just starting to trace the wire from FL13 to the BCU. It looks like it's purple with maybe a brown stripe. If I can find it, I'm thinking about cutting on each end and replacing with a jumper. Thoughts?