wiring between starter and alternator, Beta 25, access?

[FairweatherDave]

My rev counter slowly stopped showing the revs although engine running fine. From reading here I tried to find the "W" wire to the alternator, and then noticed fan belt very slack. Replaced fan belt with correct tension. To my joy the rev counter came back to life but I seem to have created an intermittent starting fault, which I am attributing to wiggling one of these wires. My short term solution has been to give another untargeted wiggle and engine has started - I have tried to induce the fault and see which wire but they all seem secure. Access is really not easy as the oil filter is in front of everything. Seems I need to remove the oil filter to clean up and redo the connections? If anyone knows which wire is which in the bundle from the alternator that would be a real bonus. (I do have the Beta wiring diagrams but struggle to make sense of them). To complete the picture the starting problem, when it happens, is that the lights on the panel come on as normal, but then nothing when I fully turn the key. I have not heard any clicks when the key is turned...complete silence.

 

[Alex_Blackwood]

My rev counter slowly stopped showing the revs although engine running fine. From reading here I tried to find the "W" wire to the alternator, and then noticed fan belt very slack. Replaced fan belt with correct tension. To my joy the rev counter came back to life but I seem to have created an intermittent starting fault, which I am attributing to wiggling one of these wires. My short term solution has been to give another untargeted wiggle and engine has started - I have tried to induce the fault and see which wire but they all seem secure. Access is really not easy as the oil filter is in front of everything. Seems I need to remove the oil filter to clean up and redo the connections? If anyone knows which wire is which in the bundle from the alternator that would be a real bonus. (I do have the Beta wiring diagrams but struggle to make sense of them). To complete the picture the starting problem, when it happens, is that the lights on the panel come on as normal, but then nothing when I fully turn the key. I have not heard any clicks when the key is turned...complete silence.View attachment 181828

Not easy to say with certainty but I would start with the two large red and black connections the red one looks, to me, to be a bit dodgy. Other than that I am afraid a bit of trial and error may be required.

 

[pmagowan]

There is definitely some corrosion on the terminals. I think it would be wise to take all of them off, clean them and remake the connections. Then give it a spray of some proprietary protection stuff. I would also replace the electrical tape with heat shrink to make an air/watertight seal. Remember that these connectors are prone to vibration and expansion/contraction from heating and cooling under load. Failure can cause a bigger problem than poor starting.

The lack of access is typical.
PS, make sure to disconnect at battery first.

 

[FairweatherDave]

Thanks both. The trial and error bit is the problem . Access is so awkward I think I need to remove the oil filter and clean all the connections up. (Obviously, with oil filter off I can't turn the engine over/fail to turn it over).
Extra question to all....does the oil in the engine sit above the height of the oil filter, can I just remove the oil filter? I don't plan to find out the hard way, quite happy to drain off oil properly if I have to

 

[BabaYaga]

When redoing the connections on the positive stud near the centre of the picture, I think it would be wise to put the large cable shoe (thick red wire, starter battery lead) on first and then the connections from the alternator/engine harness on top.

 

[pmagowan]

When redoing the connections on the positive stud near the centre of the picture, I think it would be wise to put the large cable shoe (thick red wire, starter battery lead) on first and then the connections from the alternator/engine harness on top.

Good point, an make sure there are no stainless washers between things. A washer can go on the outside of everything but should not be under connections as SS does not conduct electricity well and heats up.

 

[VicS]

My rev counter slowly stopped showing the revs although engine running fine. From reading here I tried to find the "W" wire to the alternator, and then noticed fan belt very slack. Replaced fan belt with correct tension. To my joy the rev counter came back to life but I seem to have created an intermittent starting fault, which I am attributing to wiggling one of these wires. My short term solution has been to give another untargeted wiggle and engine has started - I have tried to induce the fault and see which wire but they all seem secure. Access is really not easy as the oil filter is in front of everything. Seems I need to remove the oil filter to clean up and redo the connections? If anyone knows which wire is which in the bundle from the alternator that would be a real bonus. (I do have the Beta wiring diagrams but struggle to make sense of them). To complete the picture the starting problem, when it happens, is that the lights on the panel come on as normal, but then nothing when I fully turn the key. I have not heard any clicks when the key is turned...complete silence.

After disconnecting the battery +ve take all those connections off the starter solenoid clean them and the terminal thoroughly then replace them in the order Baba Yaga suggests (ie biggest first, smallest last). Do not put a washer, stainless or otherwise, under them, or between them but fit one on top of the top one under the nut.

Clean the connections on the battery isolating switch similarly.

Clean the battery connections before refitting

I think the negative ( earth connection) has already been mentioned

 

[Alex_Blackwood]

My rev counter slowly stopped showing the revs although engine running fine. From reading here I tried to find the "W" wire to the alternator, and then noticed fan belt very slack. Replaced fan belt with correct tension. To my joy the rev counter came back to life but I seem to have created an intermittent starting fault, which I am attributing to wiggling one of these wires. My short term solution has been to give another untargeted wiggle and engine has started - I have tried to induce the fault and see which wire but they all seem secure. Access is really not easy as the oil filter is in front of everything. Seems I need to remove the oil filter to clean up and redo the connections? If anyone knows which wire is which in the bundle from the alternator that would be a real bonus. (I do have the Beta wiring diagrams but struggle to make sense of them). To complete the picture the starting problem, when it happens, is that the lights on the panel come on as normal, but then nothing when I fully turn the key. I have not heard any clicks when the key is turned...complete silence.View attachment 181828

Beta 25 Manual. If you look at the electrical diagram I think you will find the red wire is common to alternator and starter. Good place to start. I think that your picture is in fact the starter not the alternator??
https://betamarineengines.com/application/files/3616/1051/2372/1590-1025-HEKC-SOM-0314.pdf

 

[VicS]

Beta 25 Manual. If you look at the electrical diagram I think you will find the red wire is common to alternator and starter. Good place to start. I think that your picture is in fact the starter not the alternator??
https://betamarineengines.com/application/files/3616/1051/2372/1590-1025-HEKC-SOM-0314.pdf

More specifically , the solenoid ?

would you agree the wiring is as labelled here

 

[BabaYaga]

would you agree the wiring is as labelled here

I think the labeling is spot on.
To me the OP's photo appears to be reversed.

 

[VicS]

I think the labeling is spot on.
To me the OP's photo appears to be reversed.

I think it's the angle it been taken from.
Turn your screen upside down and it looks more familiar

 

[BabaYaga]

I think it's the angle it been taken from.
Turn your screen upside down and it looks more familiar

You are correct. Upside down, not reversed.

 

[FairweatherDave]

Fantastic replies, all really useful and all the tips taken on board, from the order of the wires on the stud and disconnecting the battery first and heat shrink. The photo was taken from underneath the starter motor and presents a much better view than I can get with my own eyes. Hence my talk of removing the oil filter. Thanks VicS for the labelling on the photo, very helpful. Now feel ready to take the job on.

 

[FairweatherDave]

Just heard back from Beta on the removing oil filter part of the question......"You will lose some oil but most of it will be in the sump".....that is enough encouragement for me to just remove the filter as I normally do at annual oil change time

 

[billskip]

Just heard back from Beta on the removing oil filter part of the question......"You will lose some oil but most of it will be in the sump".....that is enough encouragement for me to just remove the filter as I normally do at annual oil change time

Yes ...but don't crank the engine because the oil pump will pump oil out of the filter manifold.
If you want to test cranking empty the old filter and put it back temporary, you may have to remove it again or change it for new when you know cranking is successful...don't start or run/rev engine with no oil in the filter.