[niks4adam]

Hi there, just looking for some pointers, I've read through a bunch of similar threads but didn't have much luck. Yesterday, out of the blue, I went outside to notice my rear license plate lights (2) were on, as well as the right rear brake light ( believe it to be the brake light, could also be a running light). We've had some zero degree F temps lately, and I did have a can of soda explode behind the passenger seat. It cracked open on the rubber mat and all of the contents were right there on the mat, which makes me believe it didn't get to the becm. I did hook up a leaf blower to dry any possible moisture out of the area, if there was any. The temperature never got back above freezing, so the soda was still solid, but turning the heat on could have thawed some of it I suppose.

Things are just really sporadic now...the interior lights all started to faintly flicker, and are now a constant on, no doors open, nor faults listed on the message center. When the interior lights started to stay on, only the glove box light wouldn't come on, all others would (someone removed the glove box and never replaced it). The brake light only comes on occasionally, and sometimes the driver's side marker light on the front comes on (North America), but goes off at random times. Everything else functions as I would expect, except these lights. Blinkers, wipers, all dash lights function. It seems like when the vehicle is at running temperature, the brake light goes out, but after cooling down, the brake light randomly comes back on. I'm getting proper voltage from the battery and alternator, so I don't think that is an issue (battery is about 2 years old). On occasion when the brake light goes off on its' own, I'll get a message on the message center that the left and right brake lights need replaced...but only every once in a while, maybe one time out of ten.

I've held down the dome light button and get the message that the interior lights are off, but that doesn't change anything. Would you expect that it is something with the becm malfunctioning? If so, if I remove it completely to inspect, will I have any issues when re-hooking it back up? I just can't really imaging what else it could be after reading through the forums. At the moment the interior lights are all on and the two licence plate lights are constant on, too. Very strange.

 

[chris no 10]

It’s possible that if you remove to inspect/clean that you might have to resync, do you have a working key fob ?. If not, do you have the EKA code,,
as the soda happened in the back of the car, I’d be more inclined to remove the seat so you can have a good look at the rear connections on the becm.

 

[niks4adam]

It’s possible that if you remove to inspect/clean that you might have to resync, do you have a working key fob ?. If not, do you have the EKA code,,
as the soda happened in the back of the car, I’d be more inclined to remove the seat so you can have a good look at the rear connections on the becm.

No, my key fob has never worked, when I bought it the receiver in the back was actually unplugged, so I don't know exactly what that means, but I never had any luck trying to re-sync it following the methods online. I do not really know what the EKA code is, so I do not have one. I'll try getting a better look in the daylight tomorrow, I'm thinking it's more of a coincidence with the soda and the lights going crazy, but I cannot be certain...hard to explain, but it all just kind of popped out of the can right in place. I picked up my floor mat, and dumped the frozen soda right off of it, it was like a slushie. I definitely want to have a good look under the seat, from what I can feel nothing is wet, but I know that doesn't tell the full story, just by feel. To be honest, I'm most inclined just to install a battery cut-off switch. Everything functions as-is, except those lights staying on. I could remove the interior bulbs, but will need the license plate lights to be fully working and not draining the battery. The vehicle is just not something I want to sink a bunch of cash into at the moment. Thanks for your help chris no 10!

 

[niks4adam]

No, my key fob has never worked, when I bought it the receiver in the back was actually unplugged, so I don't know exactly what that means, but I never had any luck trying to re-sync it following the methods online. I do not really know what the EKA code is, so I do not have one. I'll try getting a better look in the daylight tomorrow, I'm thinking it's more of a coincidence with the soda and the lights going crazy, but I cannot be certain...hard to explain, but it all just kind of popped out of the can right in place. I picked up my floor mat, and dumped the frozen soda right off of it, it was like a slushie. I definitely want to have a good look under the seat, from what I can feel nothing is wet, but I know that doesn't tell the full story, just by feel. To be honest, I'm most inclined just to install a battery cut-off switch. Everything functions as-is, except those lights staying on. I could remove the interior bulbs, but will need the license plate lights to be fully working and not draining the battery. The vehicle is just not something I want to sink a bunch of cash into at the moment. Thanks for your help chris no 10!

It's all so sporadic too...the plate lights and all interior lights were on for the last 3 hours, now it's just the plate lights and the glove box light that are stuck on. So strange.

 

[marty_nz]

Have you got the RAVE manual? There are wiring diagrams in there which might help trace any common causes of the issues...

Disconnecting the battery to check the BECM etc - you shouldn't have any issues as long as you disconnect the battery when the vehicle is UNLOCKED, as when it powers back up it will revert to the state it was in prior to losing power. So if it's locked and alarmed, then loses power, it will power back up locked and alarmed. This is the bit that seems to cause most headaches for people, as then you have to sort out unlocking, EKA, immobiliser and who knows what else if it decides to have a hissy fit! Removing power whilst unlocked generally avoids all of these issues.

Likewise, I don't generally recommend fitting a battery cut off, as it does the same thing as disconnecting the battery - and again (in my opinion) is asking for trouble.

Back to your lamps though.

I'm just having a look in the wiring diagrams myself, and looking to see where things run from.
Number plate lamps - come from C325 on the BECM and go through C307 (at the top of the tailgate, just above the headlining) before ending up at the number plate lamps
Rear Tail lights (I don't think it's the brake lights that will be the issue as they are controlled a bit more directly from the brake pedal switch) also come from C325 on the BECM. There are no other connectors in between the BECM and the light clusters at the rear of the vehicle. If it is the Brake light, then this is on the same connector from the BECM too.
LHF Park Light - This comes from C120 on the BECM, and goes through no other connectors to the side light unit
Interior lights - Main power for the front interior lamp, the loadspace lamp and the rear/right interior lamp all have a permanent 12V feed from the BECM (fuse 15) on C325. Actually controlling the interior lamps is done via the ground/-ve wire to the light units, and to these lamps, also comes from C325. The left interior lights (in the headlining) are powered/controlled through C361 from the BECM
Footwell Lamps - the front footwell lamps are also given a permanent 12V from the BECM and the ground is controlled to turn the lights on/ off. The front footwell lamps are fed/grounded on C258 from the BECM, and the rear footwell lamp (where fitted) is powered/grounded from C625 at the BECM.
Glove Box Light - this isn't controlled with the rest of the interior lights. It is powered from the BECM on C258, and is then grounded via a switch in the glove box, so it will only turn on when the glove box is open. 12V power to the light is on with the side light switch is turned on, and one of the documents I have says that you can get a number plate lamp failure if there is a problem in the glove box lamp circuit - so from that, I believe they are powered from the same source in the BECM.

As you can see from above, there are numerous connectors all coming from the top (power) board on the BECM which feed the problematic items on your vehicle. If it was all just from one connector, then I would think that it's a problem in the connector/corrosion on the pins etc.

Given there are so many connectors involved, and they are on different sides of the BECM - I would suggest removing the BECM and then taking it inside somewhere warm and opening it up to see what the state of things is on the power board.
It could be there is some mild surface corrosion, which is causing leakage of current between circuits and causing the issues you are having. If it isn't too bad, then a good clean with contact cleaner, and sometimes a scrub with an old toothbrush will get rid of the corrosion buildup and it will solve the problem.

If it doesn't sort it, then it would be worth getting hold of a replacement BECM power board. You can swap the bottom, logic board over (it's the one that's programmed with all your vehicle settings) from the faulty unit into one with a working power board - so you get a fully working unit again, but no loss of vehicle settings, or other strange stuff happening.

But before you get to the point of worrying about BECM boards and swapping stuff, i'd pull the BECM, pop the lid off and see what's going on inside.

 

[niks4adam]

Have you got the RAVE manual? There are wiring diagrams in there which might help trace any common causes of the issues...

Disconnecting the battery to check the BECM etc - you shouldn't have any issues as long as you disconnect the battery when the vehicle is UNLOCKED, as when it powers back up it will revert to the state it was in prior to losing power. So if it's locked and alarmed, then loses power, it will power back up locked and alarmed. This is the bit that seems to cause most headaches for people, as then you have to sort out unlocking, EKA, immobiliser and who knows what else if it decides to have a hissy fit! Removing power whilst unlocked generally avoids all of these issues.

Likewise, I don't generally recommend fitting a battery cut off, as it does the same thing as disconnecting the battery - and again (in my opinion) is asking for trouble.

Back to your lamps though.

I'm just having a look in the wiring diagrams myself, and looking to see where things run from.
Number plate lamps - come from C325 on the BECM and go through C307 (at the top of the tailgate, just above the headlining) before ending up at the number plate lamps
Rear Tail lights (I don't think it's the brake lights that will be the issue as they are controlled a bit more directly from the brake pedal switch) also come from C325 on the BECM. There are no other connectors in between the BECM and the light clusters at the rear of the vehicle. If it is the Brake light, then this is on the same connector from the BECM too.
LHF Park Light - This comes from C120 on the BECM, and goes through no other connectors to the side light unit
Interior lights - Main power for the front interior lamp, the loadspace lamp and the rear/right interior lamp all have a permanent 12V feed from the BECM (fuse 15) on C325. Actually controlling the interior lamps is done via the ground/-ve wire to the light units, and to these lamps, also comes from C325. The left interior lights (in the headlining) are powered/controlled through C361 from the BECM
Footwell Lamps - the front footwell lamps are also given a permanent 12V from the BECM and the ground is controlled to turn the lights on/ off. The front footwell lamps are fed/grounded on C258 from the BECM, and the rear footwell lamp (where fitted) is powered/grounded from C625 at the BECM.
Glove Box Light - this isn't controlled with the rest of the interior lights. It is powered from the BECM on C258, and is then grounded via a switch in the glove box, so it will only turn on when the glove box is open. 12V power to the light is on with the side light switch is turned on, and one of the documents I have says that you can get a number plate lamp failure if there is a problem in the glove box lamp circuit - so from that, I believe they are powered from the same source in the BECM.

As you can see from above, there are numerous connectors all coming from the top (power) board on the BECM which feed the problematic items on your vehicle. If it was all just from one connector, then I would think that it's a problem in the connector/corrosion on the pins etc.

Given there are so many connectors involved, and they are on different sides of the BECM - I would suggest removing the BECM and then taking it inside somewhere warm and opening it up to see what the state of things is on the power board.
It could be there is some mild surface corrosion, which is causing leakage of current between circuits and causing the issues you are having. If it isn't too bad, then a good clean with contact cleaner, and sometimes a scrub with an old toothbrush will get rid of the corrosion buildup and it will solve the problem.

If it doesn't sort it, then it would be worth getting hold of a replacement BECM power board. You can swap the bottom, logic board over (it's the one that's programmed with all your vehicle settings) from the faulty unit into one with a working power board - so you get a fully working unit again, but no loss of vehicle settings, or other strange stuff happening.

But before you get to the point of worrying about BECM boards and swapping stuff, i'd pull the BECM, pop the lid off and see what's going on inside.

Wow, thanks Marty! You know your stuff and I truly can't thank you enough for taking a look at that! As long as I won't have too much trouble with any pairing or syncing type things from physically unplugging the becm (not worried about the key fob as the remote never worked for me), I will probably do that, I'm a tinkerer, so it would be a good project to just take it apart and do some cleaning regardless. Also thanks for pointing out that my things are isolated to one board, I wouldn't have figured that out, and I saw that replacement becm's weren't too expensive, it was the programming/cloning that instantly gave me hesitation.

You're right about the battery cut-off...I can think of a lot of scenarios that, while it could be a stop gap workaround, seem like a terrible idea. Definitely not one I would like to do.

Strangely, today, at least so far, I'm down to just the license plate lights being on, but they are now on extremely dim, not fully on until I turn on my headlights. The interior lights have all turned off, and I still have the dome light set to "interior lights off", but the glove box light does come on when I turn on the headlights (the glovebox is physically missing, previous owner took it out), but it is shutting off as it should at least. The dim license plate lights make me think the battery is going to be dead when I try to start it, but that's not the case (I changed them to LED about 6 months back, fyi).

I think my next step is to take out the becm as you suggested and give it a look over and cleaning, I think it's the first time since I've owned the P38 that the temperature has dropped to this low, but maybe the conditions were all perfect after turning on the heat to cause a circuit to be shorting out or be incomplete.

Thanks again Marty!

 

[Gordo51]

You know if it was me and I just had license plate lights that were not co-operating I would just take out the bulbs until a Mountie told me to put them back in. The way things are going they might actually go back to normal. Strange things happen with these early P38s. My power windows, mirrors and sunroof stopped working a few weeks ago. Since I don't open the windows much in the winter I decided to forget about them for now (although I did put the center console switch pack into my 2000 where it worked fine so not a switch pack problem). Today I was off-roading with my Land Rover club (RoverLanders of BC) and they started working again. Hooray except that my EAS went into fault mode and dropped to the bump stops. I had to go home early as driving over pot holes while on bump stops gives you a real appreciation for having your seat belt fastened. Tomorrow I may sub in another compressor/valve block and clear the faults with my Hawkeye to see if it will cooperate. Such amusement.....Good luck with your Rover.