I am finally pulling all of my electrical improvements together. One thing left undone was modifying the negative cable from the alternator. I have an Hitachi 80A alternator that was factory installed with my new 2YM15 (Yanmar) engine. Original install included a red 10 awg pos lead to the starter + post and a black 10 awg neg lead to (presumably) engine grounding.
Last year, I disconnected the + lead and routed a new 4 awg cable to a POS buss bar near the battery terminals. Luckily, the POS lead was readily accessible. I'm using a Blue Seas ACR with DCP switch. The ACR is wired with 6 awg cables as shown in MS's wiring diagram for DCP with 2 emergency isolation switches. I have the cable from the alternator fused at the buss bar. The cable is 10' long to snake around the engine and back to the batteries. (I didn't need 10' and could shorten it to 7').
My question is about the NEG lead from the alternator. I simply can't get to it, probably unless I take the alternator off for access. So I've left it alone, thinking it alright. I know that wiring diagrams show the alternator lead routed to a NEG buss bar, which is then grounded to the engine and I want to make this system ABYC compliant. Should it be necessary to run a 4 awg cable to the NEG buss? What are the consequences for leaving the original 10 awg lead in place instead? I understand the size is based on the round trip circuit, but does this apply to the alternator? Basically, I'm concerned about that small diameter grounding wire and will replace if necessary, but how do I get to it? It is tight against the engine and even if I could see the connection well, I doubt I could get my fingers in there. Does this mean removing the alternator? Thanks for any and all replies!
Last year, I disconnected the + lead and routed a new 4 awg cable to a POS buss bar near the battery terminals. Luckily, the POS lead was readily accessible. I'm using a Blue Seas ACR with DCP switch. The ACR is wired with 6 awg cables as shown in MS's wiring diagram for DCP with 2 emergency isolation switches. I have the cable from the alternator fused at the buss bar. The cable is 10' long to snake around the engine and back to the batteries. (I didn't need 10' and could shorten it to 7').
My question is about the NEG lead from the alternator. I simply can't get to it, probably unless I take the alternator off for access. So I've left it alone, thinking it alright. I know that wiring diagrams show the alternator lead routed to a NEG buss bar, which is then grounded to the engine and I want to make this system ABYC compliant. Should it be necessary to run a 4 awg cable to the NEG buss? What are the consequences for leaving the original 10 awg lead in place instead? I understand the size is based on the round trip circuit, but does this apply to the alternator? Basically, I'm concerned about that small diameter grounding wire and will replace if necessary, but how do I get to it? It is tight against the engine and even if I could see the connection well, I doubt I could get my fingers in there. Does this mean removing the alternator? Thanks for any and all replies!