BF135 Mil light

Hi Guys ,

Just need some advise on couple of faults im trying to sort on a pair of BF135's on a boat i have recently purchased. I have been through fuel system and electrics , codes etc in shop. This was a boat that previous owner had given up on so had a bunch of issues that I thought I had covered.

All ( in shop ) problems sorted and was running good out of water until first sea trial this weekend

Both OB's wont rev above 3000 rpm, on the water or in the workshop in a trough.
Both MIL lights are also on when engines are running (oil light on, temp light off, batt light off, MIL light on) Is this normal on this model engine - have read various post and cant confirm if it should be off or on with engine running? Could have sworn MIL's were off on early in shop testing..

Boats now out of water again and tried to pull codes but MIL's didn't flash ... so guessing either none stored or MIL's staying on is a deeper problem.

Cheers

Mil light should come on for about 5 secs when ignition is turned on and the stay off when starting and running. If there is an issue the alarm should be sounding. I would imagine there is an issue with the wiring given that both engines have the same issue. The same applies to the rpm, does the boat perform well, could the tachos be incorrectly set, is the boat correctly propped,is the boat full of growth, it is highly improbable for twin engines to have identical faults

Hi iang6766,

Thanks for confirming the MIL light operation. I did suspect that they were supposed to be off but second guessing myself...
Anyway believe was all in order before i did rerouting of main looms and had my boys add lights , radio's etc so something has been wired wrong or messed up somewhere. At least now I know where to start - thank you

The boat performs great, never been in a permanent berth so bottom is clean and as new.

I just pulled one of the 2 Honda / Faria analog tachs and its set to position 3 ( 8 pole ) . From what I have read elsewhere this morning they should be set to position 1 ( 4 pole ) is that correct? That would certainly make sense if the tach's are giving false reading as the boat goes great... and even running at what I thought was 3000 PM seems fast enough ( 30 Knots on GPS )

Look forward to your comments

Cheers

Correct, tacho should be set on 1

Thanks again iang6766.

Flicked the switch over to 1 and all good on the port side and no doubt will be the same STB when i do it.

With the glowing MIL lights ( both engines) ... I revisited it again and both are glowing but not as bright as when MIL flashing codes or on initial key-on self test...No codes stored on either engine until i started unplugging sensors to make a code and flash to see if on permanent or what...So not sure what this is telling me now. So key on MIL glows bright for about 5 seconds then dulls but is still clearly visible... Any suggestions? Or just leave it alone?

Sounds like you're getting a voltage bleed over to the indicator lights. There are four plugs from the wiring harness coming from your engine and going to the key switch - 3 prong, 6 prong, 4 prong, and 4 prong. Pull each of them, inspect for corrosion or bad wire at the connector, spray with electrical cleaner and reattach to test.

See attached.

View attachment Electrical Diagram Honda Digital Gauges Dual engines.pdf

Hi CHawk,

Cleaned up all wiring at remote and engine ends. Nothing corroded or loose. This is a twin engine setup so besides having issues with MIL glowing ( at 50% of normal ) - having it happen on both engines is strange. On the 3 pin plug that feeds the MIL and Batt light there is only two wires going into the remote. Seems that the red/blue is the earth side of the MIL and appears switched on by the ECM... I have checked continuity and its good remote end of loom to the ECM plug.

I just did a test with a meter from engine main power feed to red /black wire while main harness plugged into ECM to try and prove good earth. Reading meter with battery on-key off getting battery voltage, when key on remains at battery voltage until a few seconds later the voltage drops down to 7.5V. ( i would have thought it should be zero ) All while this is happening MIL light does everything it is supposed to but after self test still glows at about 50 + percent of what it would do when on initial self test or flashing codes.
I have just removed all battery isolator switches and battery cross over switches and accessory feeds out of the batt wiring circuit to try and eliminate any possible voltage / earth issues......Also disconnected the gauge wiring from main loom. Fault still remains - both engines. There are no codes or alarms going off or stored and MIL will flash if a sensor is disconnected and clears codes as normal...

Not sure where to go from here

what year are these motors and what kind and year of remotes are you using? If you have new remotes with older engines then that is your problem. The older motors require 3 wires into light panel whereas the new ones only have 2.

If you could post a pic of your set up I may be able to help

Hi iang6766
Hopefully photo of remotes attached
Engines are twin BF135A BARJ-1003506 / BASJ-1000280 I do not know the year but had been told 2004
Remotes are pair of new looking Honda side mount type. 4 light , with individual ignition switches.
Just as an aside... The boat originally ran twin Yamaha's and for reasons unknown they were swapped out with the Honda's a couple of years ago. I suspect the remotes and gauges were purchased back then for the conversion as all looking new-ish

iang6766
Just adding some more photos and info.
So if this remote is not compatible with the engine need to figure out what wiring can be changed to make it work if possible. All other functions on remote work including ability to flash codes etc. I presume the 4 lamp cluster - or at least the Batt/ALt and MIL lights are getting power from somewhere else internally with current set up but were ( or should have been ) getting power from red /blue wire on earlier remote set up .
Any help at all would be appreciated
Cheers

sorry... last line should have read....
getting power from yellow / black wire on earlier remote set up .

iang6766 , CHawk any ideas on this?

I have found a couple of dodgy earths that I will get sorted today but besides that I'm at an end as what to do besides buying new (older type ) remotes...Trouble is everything works as it should besides the semi glowing of the MIL lamps and being based in Papua New Guinea not easy to get any remotes to "try"

Cheers

Guys, Haven't had any feedback from here for couple of days so please help as I'm still struggling with where too next. Any help at all would be appreciated.
Cleaned up all engine earths/ grounds and they weren't great but no change to the always semi glowing MIL light. Pulled one remote apart to check wiring and nothing obvious inside. In fact haven't come across one bad wire or terminal on the whole set up besides the poor looking earths. I basically bypassed the wiring to the remotes and fired up the 4 lamp display right out of the ECM itself. Cut the red/blue wire thats the ecm/earthing side for the MIL and wired it up and still the same semi glowing MIL after done self check at regular brightness. when i put a multi meter from power to the ecm red /blue MIL wire on ecm Im getting 12V the it drops down to 7.5 v when it should be 0 v . There is something that is telling the ecm to not turn the earth of the red/blue wire that is the earthing side of the MIL light. I have swapped ECMs from other engine ( doing exactly the same with the MIL light ) and still same. I have continued to "make codes" and the light does flash brightly but alway reverts to going dim whilst not flashing. I can clear codes but still have semi glowing MIL no mater what i do. I have run through the "MIL staying on" and "MIL not coming on" via the manual but nothing is at fault with anything I have checked.
What are the chances I have 2 bad ECMs?
Is there something Im missing or have overlooked. ?
At at the stage now of thinking about putting a toggle switch on the red/blue wire and at least can turn the MIL off and back on when need to reed codes...
Not sure what else to do.

The only thing you can do is order 2 sets of the old stand alone mil lights, that's check eng and battery, plug your 3 pin into that and it will be fine, your check eng and charge on the control box will become redundant but the oil and temp lights will work normally

The light panel you need is 32340 ZW7 000AH

Apologies for the late reply, I never got notification of your reply.I mentioned before, your motor's will not work with the new 2 wire set up, so just mount the light panels mentioned in previous post in a convenient place and it'll all be good.

Thanks iang6766, <br><br>Yes you did mention earlier that the engines and remotes were not compatible and I did look into purchasing new but was concerned that the pair I had lined up seemed to be the same as what I have. IE only 2 wires for the MIL/Batt<br> I'm currently working in Papua New Guinea so no Honda dealers and no way to "try" or test a new remote<br><br>Changing to the separate 2 light panels and using the 3 pin cable sounds like great option<br><br>Thanks for your assistance once again and i will come back and let you know once parts received<br><br>Cheers<br><br><br><br><br>

Just did a quick search, you will find that light panel with ease on ebay, just type in the part number.

Thanks for that, Yes done same and seen some new ones on Ebay Australia for $30 each. so will chase them Monday

Cheers

Hi, I had the same issue on my BF150, mil light glowing when supposed to be off. Solved it by switching it to ground using a normal automotive micro relay, cost 3$ and a few wires. The relay closes when the 12V is applied and "drops" when voltage over the coil drops to 7V.

Yes I was getting to that stage too but just received the 2 light panels that iang6766 suggested, plugged in and all working as it should

That's was one long road to learning Honda electrics - I guess - but very happy its sorted now

Cheers iang6766 once again