Andy135 Posted December 12, 2021 Share Posted December 12, 2021 My Suzuki DF300 outboard has two regulator/rectifiers that provide the ability to charge both the house and start batteries. On Jersey Girl the house battery wasn't getting charged, despite having the optional sub-loom and 30A fuse to provide power to the battery. My marine engineer took a look and suggested a replacement regulator/rectifier assembly (which comes from Suzuki Germany at nearly £400). Eventually it arrived and he forwarded it on to me for fitting. Upon lifting the engine cowling to take pictures of the old unit in place as a guide for fitting the new one, I happened to notice this... The earth lead from one of the R/R units was disconnected! How was this missed? I wonder if this has been disconnected since the factory, as I can't see why a previous owner would have had a need to remove it. A quick twiddle with a 12mm spanner was all it took to refit it. I fired the engine up on muffs and checked the voltage at one of the MFD's. 12.1v with engine off and 14v with engine running. So this tells me that the House circuit is now being charged. Success! So I will be sending back the unused R/R assembly... 🤦♂️ suzook12 1 Quote Link to comment Share on other sites More sharing options...
Odyssey Posted December 12, 2021 Share Posted December 12, 2021 Sounds like you need to send the mechanic back too 🤣 Quote Link to comment Share on other sites More sharing options...
GPSguru Posted December 12, 2021 Share Posted December 12, 2021 But, you need to ask yourself, 1) was it left accidentally disconnected after other engine work.🙄 or 2) was it disconnected due to another issue which was traced to the charging circuit ? 🤔 Next time you go out, best make sure you take a 12mm spanner with you. 😉 Quote Link to comment Share on other sites More sharing options...
Andy135 Posted December 12, 2021 Author Share Posted December 12, 2021 5 minutes ago, GPSguru said: But, you need to ask yourself, 1) was it left accidentally disconnected after other engine work.🙄 or 2) was it disconnected due to another issue which was traced to the charging circuit ? 🤔 Next time you go out, best make sure you take a 12mm spanner with you. 😉 I've already had the same thoughts. Might keep hold of the new R/R until I've done a few NM and given her a shakedown. 🤔 GPSguru 1 Quote Link to comment Share on other sites More sharing options...
suzook12 Posted December 12, 2021 Share Posted December 12, 2021 You need to know what it charges at under load and at idle as well as 3k rpm Next time you're out, take an extra pair of hands that can work a multimeter. It does sound like a resounding success, but there will always be that nagging doubt until its tested. You want to measure battery volts at the battery, any dodgy connections can result in the battery seeing 18+ volts but showing upstream as 13-14v - Dont ask how I know this...... Quote Link to comment Share on other sites More sharing options...
Andy135 Posted December 12, 2021 Author Share Posted December 12, 2021 48 minutes ago, suzook12 said: You need to know what it charges at under load and at idle as well as 3k rpm Next time you're out, take an extra pair of hands that can work a multimeter. It does sound like a resounding success, but there will always be that nagging doubt until its tested. You want to measure battery volts at the battery, any dodgy connections can result in the battery seeing 18+ volts but showing upstream as 13-14v - Dont ask how I know this...... This is my concern - that a previous owner disconnected the House R/R because it cooked a battery. Next time I'm out I'll test the battery at the pontoon. I have a throttle-only setting on the helm, so I can disengage the gearbox then set the RPM's to whatever I choose and test the voltage at the battery single-handedly while stationary. If I see more than 14v at the battery I'll switch out the old R/R for the new one. Quote Link to comment Share on other sites More sharing options...
GPSguru Posted December 12, 2021 Share Posted December 12, 2021 1 hour ago, suzook12 said: You want to measure battery volts at the battery, any dodgy connections can result in the battery seeing 18+ volts but showing upstream as 13-14v - Dont ask how I know this...... One of the joys of using a very high impedance instrument, sometimes when fault finding on batteries it is better to use an old moving coil voltmeter. Although my Fluke 77 gets used a lot, sometimes I still rely on my old Avo 8 Quote Link to comment Share on other sites More sharing options...
GPSguru Posted December 12, 2021 Share Posted December 12, 2021 (edited) 42 minutes ago, Andy135 said: This is my concern - that a previous owner disconnected the House R/R because it cooked a battery. Next time I'm out I'll test the battery at the pontoon. I have a throttle-only setting on the helm, so I can disengage the gearbox then set the RPM's to whatever I choose and test the voltage at the battery single-handedly while stationary. If I see more than 14v at the battery I'll switch out the old R/R for the new one. Good plan, but other symptoms of a faulty unit could be strange instrument readings and also misfire at high revs or under load. This would be due to the R/R putting out a substantial AC ripple onto the DC line. However, looking at the picture, it would seem likely that reconnecting the earth was missed during routine servicing, or other engine work. Edited December 12, 2021 by GPSguru Quote Link to comment Share on other sites More sharing options...
Andy135 Posted December 12, 2021 Author Share Posted December 12, 2021 28 minutes ago, GPSguru said: Good plan, but other symptoms of a faulty unit could be strange instrument readings and also misfire at high revs or under load. This would be due to the R/R putting out a substantial AC ripple onto the DC line. Good to know. Will keep an eye out. Quote Link to comment Share on other sites More sharing options...
Andy135 Posted December 12, 2021 Author Share Posted December 12, 2021 28 minutes ago, GPSguru said: However, looking at the picture, it would seem likely that reconnecting the earth was missed during routine servicing, or other engine work. The earth strap eye looked very fresh, and I don't remember it looking like it had witness marks on it from being previously fastened, which leads me to suspect it's been missed at the factory. It was tucked away behind the main engine earth strap that you can see in the picture - I moved it out in order to take the photo. As for being removed for other engine work, I can't think of any other work that would require the R/R's to be removed. Quote Link to comment Share on other sites More sharing options...
suzook12 Posted December 12, 2021 Share Posted December 12, 2021 1 hour ago, GPSguru said: One of the joys of using a very high impedance instrument, sometimes when fault finding on batteries it is better to use an old moving coil voltmeter. Although my Fluke 77 gets used a lot, sometimes I still rely on my old Avo 8 Actually, mine was owing to a dodgy contact in the ignition switch, which meant the alternator was only seeing around 10V, so its output kept upping until it saw 13.8, meanwhile, my smoking nitrous controller was visited by 18V..... GPSguru 1 Quote Link to comment Share on other sites More sharing options...
Andy135 Posted December 13, 2021 Author Share Posted December 13, 2021 19 hours ago, Odyssey said: Sounds like you need to send the mechanic back too 🤣 Well, to be fair we both missed it during the first inspection. I've quizzed him on why it would have been disconnected and he's suggested the same as @GPSguru and @suzook12, that the R/R isn't regulating the volts to the House circuit any more. A quick "fix" by a previous owner would have been to disconnect it instead of replacing it. Quote Link to comment Share on other sites More sharing options...
Odyssey Posted December 13, 2021 Share Posted December 13, 2021 5 hours ago, Andy135 said: Well, to be fair we both missed it during the first inspection. I've quizzed him on why it would have been disconnected and he's suggested the same as @GPSguru and @suzook12, that the R/R isn't regulating the volts to the House circuit any more. A quick "fix" by a previous owner would have been to disconnect it instead of replacing it. It’s worth checking it with a cold engine and after it’s run for a while in case you get temperature based drift… GPSguru 1 Quote Link to comment Share on other sites More sharing options...
Andy135 Posted December 13, 2021 Author Share Posted December 13, 2021 46 minutes ago, Odyssey said: It’s worth checking it with a cold engine and after it’s run for a while in case you get temperature based drift… TBH I'm pretty close to just swapping out the R/R and calling it done. Best case is that I find the 10 year old unit still works... but for how long? There is value in peace of mind. Quote Link to comment Share on other sites More sharing options...
Saintly Fish Posted December 13, 2021 Share Posted December 13, 2021 7 minutes ago, Andy135 said: TBH I'm pretty close to just swapping out the R/R and calling it done. Best case is that I find the 10 year old unit still works... but for how long? There is value in peace of mind. You could always eBay the old unit. Seeing as its fully functioning atm somebody will buy it! Quote Link to comment Share on other sites More sharing options...
Odyssey Posted December 13, 2021 Share Posted December 13, 2021 9 minutes ago, Saintly Fish said: You could always eBay the old unit. Seeing as its fully functioning atm somebody will buy it! Good idea 🙂 Quote Link to comment Share on other sites More sharing options...
GPSguru Posted December 13, 2021 Share Posted December 13, 2021 5 hours ago, Andy135 said: TBH I'm pretty close to just swapping out the R/R and calling it done. Best case is that I find the 10 year old unit still works... but for how long? There is value in peace of mind. Another reason why it may have been disconnected is due to a faulty battery, that has probably now been sorted. Batteries with S/C cells, or H/R plate coneectors cause all sorts of issues with charging systems. Quote Link to comment Share on other sites More sharing options...
Andy135 Posted January 15, 2022 Author Share Posted January 15, 2022 An update to close out this issue. I swapped out the old R/R for the new one just before Christmas and had the chance to test it on our run out yesterday. The new unit gives 13.5v at 4k rpm, compared to the old unit giving 14.7v at 2k rpm. So it seems that the old unit is no longer regulating the voltage, must be why it was disconnected. Quote Link to comment Share on other sites More sharing options...
suzook12 Posted January 15, 2022 Share Posted January 15, 2022 9 hours ago, Andy135 said: An update to close out this issue. I swapped out the old R/R for the new one just before Christmas and had the chance to test it on our run out yesterday. The new unit gives 13.5v at 4k rpm, compared to the old unit giving 14.7v at 2k rpm. So it seems that the old unit is no longer regulating the voltage, must be why it was disconnected. 14.7 is acceptable, pretty much top limit tho..... And it will all depend on electrical load Quote Link to comment Share on other sites More sharing options...
Andy135 Posted January 15, 2022 Author Share Posted January 15, 2022 8 minutes ago, suzook12 said: 14.7 is acceptable, pretty much top limit tho..... And it will all depend on electrical load Well, that 14.7 was measured at the head unit, so taking some losses into account the R/R was probably putting out a bit more. Anyways, it's done and replaced now. Quote Link to comment Share on other sites More sharing options...
GPSguru Posted January 18, 2022 Share Posted January 18, 2022 On 1/15/2022 at 8:42 PM, Andy135 said: Well, that 14.7 was measured at the head unit, so taking some losses into account the R/R was probably putting out a bit more. The absolute max I would be looking for is 14.4V at the battery. What I need right now is a Body Control Module (BCM) for the Jeep, and they are no longer available ! To add insult to injury, most of the Remanufacturers just don't list them, and it is very part number specific. The fault is intermittent, but present 75% of the time, so I might see if 'BBA Reman' can do a reflow on the circuit board for me. Quote Link to comment Share on other sites More sharing options...
Andy135 Posted January 18, 2022 Author Share Posted January 18, 2022 20 minutes ago, GPSguru said: The absolute max I would be looking for is 14.4V at the battery. What I need right now is a Body Control Module (BCM) for the Jeep, and they are no longer available ! To add insult to injury, most of the Remanufacturers just don't list them, and it is very part number specific. The fault is intermittent, but present 75% of the time, so I might see if 'BBA Reman' can do a reflow on the circuit board for me. Or find a good used one from an online scrapyard? Quote Link to comment Share on other sites More sharing options...
GPSguru Posted January 18, 2022 Share Posted January 18, 2022 7 minutes ago, Andy135 said: Or find a good used one from an online scrapyard? I have been looking, but 2003/4 is like rocking horse poo, plenty of 2005/7, these fit but are not compatible ! Quote Link to comment Share on other sites More sharing options...
suzook12 Posted January 18, 2022 Share Posted January 18, 2022 7 minutes ago, Andy135 said: Or find a good used one from an online scrapyard? A lot of these things are coded so you would need virtually the whole electronics package or being able to recode..... A lesson I learnt from Iveco 🤣 Couldn't say if Jeep are or aren't, but wouldn't surprise me.... Quote Link to comment Share on other sites More sharing options...
GPSguru Posted January 19, 2022 Share Posted January 19, 2022 27 minutes ago, suzook12 said: A lot of these things are coded so you would need virtually the whole electronics package or being able to recode..... A lesson I learnt from Iveco 🤣 Couldn't say if Jeep are or aren't, but wouldn't surprise me.... Sort of, but Jeep have made life easy with this module. The Immobilizer / keyless entry is part of the Body Control module, but it is a separate plugin unit, so is easily be changed / swapped over. The only real nightmare is that the BCM is Model specific, ( ie LHD, RHD, Key less entry, Front Fogs, etc) and the part number is also model specific, I just need to find a BCM with the same part number, which I now have, from a dealer in Germany, but at £38 it is worth the risk for a S/H part. The BCM is the only common denominator to the fault, and they are known to fail, with all sorts of random electrical issues. The fault is currently ............. indicate left and the tail gate locks, the rear wiper operates, sometimes the front wipers operate, and sometimes the alarm goes off (which is cleared by a press of the keyfob). If you indicate right for a flash or two, this clears the fault until the next ignition on cycle. I have eliminated the indicator / wiper stalk, and the Jeep towing lights module. This model does not have CanBus, it is pretty much conventional wiring. If it is the fault, then I will ship it off to BBA Reman in Kent to get all the old capacitors changed, and the surface mount circuit board reflowed. Quote Link to comment Share on other sites More sharing options...
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