Yanmar 1GM wiring loom - lead to generator

[blackbeard]

Recently had trouble with the 12 v generation with Yanmar 1GM - problem seems not to be in the generator itself but in the lead which goes to it and supplied 12v for the exciter coils (have I got that right?). Result is a red light on the instrument panel and batteries not charging.
Problem is intermittent and is affected by manipulation of the wiring leaving the loom to go to the generator.
Intention is to open up the wiring loom/harness in this vicinity and attack a break in the wiring with a soldering iron, maybe solder in a new bit of wire. However I am advised this might not be as easy as it sounds.
Has anyone had this trouble, and if so how was it dealt with, and was this successful? Any things to be aware of? Do I need a new loom?(I hope not!). Should I call in the expensive experts? Worth an amateur try, and then call in the experts if it doesn't work?

 

[Seamechanic]

Hi,
If the wire you're thinking about is broken you wouldn't have the red light on. If the problem has to do with the harness you should look for a short connection to ground . This would lead to no charge and red light on.

 

[lw395]

Is this the famous (?) fuse buried in the wiring loom?

 

[VicS]

Recently had trouble with the 12 v generation with Yanmar 1GM - problem seems not to be in the generator itself but in the lead which goes to it and supplied 12v for the exciter coils (have I got that right?). Result is a red light on the instrument panel and batteries not charging.
Problem is intermittent and is affected by manipulation of the wiring leaving the loom to go to the generator.
Intention is to open up the wiring loom/harness in this vicinity and attack a break in the wiring with a soldering iron, maybe solder in a new bit of wire. However I am advised this might not be as easy as it sounds.
Has anyone had this trouble, and if so how was it dealt with, and was this successful? Any things to be aware of? Do I need a new loom?(I hope not!). Should I call in the expensive experts? Worth an amateur try, and then call in the experts if it doesn't work?

If you do not have one you may find the wiring diagrams in the Service manual at https://www.manualslib.com/manual/791391/Yanmar-1gm10.html useful

 

[blackbeard]

Thanks for replies so far.
Has anyone tried to find an open/short circuit on a wiring loom? not as easy as it sounds I'm told, but at least I (think I) know the approximate location of the fault. Any words of wisdom before I dive in with insulating tape/soldering iron?

 

[PaulRainbow]

Thanks for replies so far.
Has anyone tried to find an open/short circuit on a wiring loom? not as easy as it sounds I'm told, but at least I (think I) know the approximate location of the fault. Any words of wisdom before I dive in with insulating tape/soldering iron?

You can sometimes find a break in wire by firmly pulling the end, if the core is broken the insulation will stretch.

First thing i would check would be all of the connections, make sure they are clean and tight and the wire is still firmly crimped to the connector.

 

[blackbeard]

Thanks for replies - sorted now (I hope!).