New Member Intro And F150 Ground Cable Question

[jupiter2360]

Hello group I am a backyardigan (coming from years of carbed 2 strokes) and new owner of 2006 F150/LF150 TXR's with 520 hours on a 2006 Sailfish 2360 cc located in Jupiter, Fla. I have read through numerous forum posts regarding F150 issues and thank the group for the good inputs provided. I have done complete service with excellent professional (30 year Yam guy) mobile help on both engines since buying including new balancers (both original with no oil port and one whining), internal anodes, VST filters, pretty much all PM services except new style poppits and spring due to forgetting to order rubber grommets. I drained oil from drain screws (they were in tight) successfully but will not be doing that again and have bought a pump rig. Switched to Mobile 1 10w-40. Need also to do four trim seals as two wiper seals are cracked up and PO had trim fluid stored in console. No real operational complaints at his time. I like to venture with family far and am very particular on engine/systems reliability and could care less about my peeling cowl decals and sunbeat top of cowl BTW.

I am replacing some cables and re-lugging others at this time due to substandard original rigging as well as cleaning up numerous poor Sailfish wiring issues. The boat has four group 24 batteries (2 start two deep cycle wet DEKA) located in console and two perko 1 2 all switches with always hot bilge pumps loads on the hot side of one switch. I am installing a blue sea dual circuit plus switch to isolate and run both starting batteries though to each engine. I have connected two 10 ga leads (20 foot wire run engine to batteries) with 50 amp fuses to the aux charging leads to charge house batteries and will connect to a new 1 2 all blue sea switch for house loads. Plan on jumping from hot posts of house switch to a new third switch dedicated soley to 6 gang fuse block for always on loads (3 auto bilge pumps) for the abiliity to shut down pumps if on trailer or a lift.

My question is regarding the battery cable requirements. First question is regarding the negative battery cable requirement. Currently have only a single 1/0 SGT black neg cable from batteries (all 4 batt tied together with negative cables) running about 16 feet to a single negative powerpost. Both engine negative cables stacked on this single negative powerpost. Should there be two negative cables returning to the batteries from the single power post? Should I have two independent negative powerpost for each engine with two independent negative cables back to batteries? (obviously this has worked for 12 years as is).

Second question is regarding the existing SGT 1/0 cabling (both positive cables and the single negative runs back to powerposts). This SAE cable has has thick individual bare copper strands (clean looking cut back 1 inch from lugs) and is not very flexible and I know has less ampicity than AWG of same size. Should I replace 1/0 SGT SAE cabling to AWG 1/0 tinned marine cable ( I always use Pacer Group marine wire local to me)?

The reason for my wire cleanup is to fix the screwy OEM setup and some crusty connections that are 12 years old . I do have an infrequent random intermittent no start condition on port motor (trim works fine during condition) and believe I may have a stater relay going bad. I have already cleaned all engine grounds and block with possible marginal improvement. Have heard a click during an episode or two.
Secondly I have batteries chargers and new starter batts are usually at 12.7 v, 12.7 v at power posts, 12.7 at starter (static) BUT the square guages usually show 12.3 resting dropping to 10.3 v during start and quickly to 13.9 v after start with idle at 14.1 fast idle 14.3. Is this discrepancy of gauge 12.3 v display when I have 12.7 normal or is there something I should be troubleshooting?

Thanks for feedback and direction.

[TownsendsFJR1300]

I have the exact same engine (single engine, normal rotation). I also had intermediate start issues, clicking from the relay, but no crank.

You can remove the fuse cover, port side, and either test voltage output (when clicking), or if out at sea, JUMP the two terminals.
If it's the relay the engine will crank when jumped..

After replacing the relay, I cut it up and found the issue inside. A burnt contact;

[jupiter2360]

Thanks for reply, I have read a previous post of yours about your relay cutting when I first investigated the no start condition but hadn't seen this pic. I thought I had the no start issue licked after meticulously cleaning all positive and negative studs and lugs and ring terminals from battery to block (and block surface which was clean and without paint) I could find with a SS wire wheel on my dremel. Problem is very infrequent and usually will start after a few more tries. One time I had the cover off is when I was able to hear a click. Problem is it happens infrequently and usually just once o rtwice before cranking over so it has been difficult to test by jumping relay.

What do your gauges show as a resting voltage as compared to actual measured battery voltage? How low does your gauge voltage drop during cold cranking before she fires?

[TownsendsFJR1300]

Those contacts are inside and took 15-20 minutes to get to with an air grinder(very stout piece of plastic).

Years ago, it clicked about 5 times in a row. Pulled the cowl, got my meter and of course , it started immediately...
I did learn you can jump it (for me, absolutely necessary to know being a single engine vessel) from the two terminals. I
now carry a very short jumper cable in the tool box just in case.

Re voltages, I don't remember. It drops a little more when cold (not much) and starts easily within 2-3 seconds cold..


The boats at a neighbors house now (can't check), as I'm supposed to get a failed sea-wall replaced starting this week..

The boat is normally on a lift, one battery, no switches. And I have a top of the line charger I'll turn on once a week. The battery is somewhat older but passes a load test easily...


My T&T relay, is intermediate now (mostly in the down position). That'll be the next project once the boats back home..


Remember, our engines are technically 11,12 years old.. That's a bunch of current on those small points over time..

[jupiter2360]

Of note is I have read the Dealer Yamaha Tech Exchange 02014 dated 2/7/14 which updated the min battery specs, cable extension size and max. length, and on page 8 the graphic example of twin engine rigging showing twin engine 4 battery with a negative cable from each engine to separate tied together batteries however no power post or distribution buss is shown in graphic. I also guess that because you are not likely to start each engine simultaneously that a high amp load to overload a single negative return cable would not occur. I am curious about the yamaha graphic and practical rigging experience and real-life experience where problems from this arrangement have been seen. I am going to make a run this week to Pacer Group for supplies to clean this up but do not want to spend any extra coin on another 18' of pricey 1/0 AWG black if not needed.

[jupiter2360]

Thanks again Scott. Don't sweat it there is no need to to check gauge voltage just thought you may have noticed it before. I hear you about the age of our motors unfortunately although mine are low hours the PO deferred a lot of PM and general overall care of boat. It was a pricey hit to get everything done so far and I still have 4 trim seals to do then who knows what! Good news I have a friend a pair of 2006 F150s that just turned over 2000 hours on a 25 Contender. He would like to repower but they keep running strong and reliable with care.

[jupiter2360]

Does anyone with experience recommend scapping the powerposts and just running new 1/0 AWG straight from battery switches to engine starter stud and negative stud on block? I am starting over and this would be the opportune time to do this. I have read about problems with the engine supplied cables however mine look pristine. I am currently not tapping into the powerposts for any other loads or devices and don't think there is a good reason for them other than ease of rigging and saving money on extra length of 1/0 AWG. My rigging tubes are tight especially the transom to grommet TH marine but was able to get the 10 AWG through each fairly OK and there was an open small bottom hole in cowl grommet for the new wire. I think with enough lube I could get em pulled then crimp in lugs afterwards. Don't remember if the grommet hole for the factory cable is a double as factory cables are joined. I guess there is enough meat in grommet to drill enlarge hole to get fatter 1/0 AWG in grommet. Is soldering the lugs on necessary if use a hydraulic crimper and closed end lug? Any advice?

[pstephens46]

Power posts can be an issue. They are the first place I look now when having issues. They should be mounted on the side of the bilge. Not anywhere near the bottom. Terminals should also have protective covers.

I have not not heard of replacing the engine side cables with a straight run from battery. Google voltage drop testing to help narrow down the issue when it happens next time. I chunked a few dollars at the same problem and learned the hard way.

Put your meter leads directly on battery to get the exact reading. My dash guage is about 0.4 volts off as well.

[TownsendsFJR1300]

I have not not heard of replacing the engine side cables with a straight run from battery. .

My Yamaha factory cables run direct from the engine to the battery, no battery switches.

Probably have another 1.5' of battery cable tied up inside the battery area..

[pstephens46]

My Yamaha factory cables run direct from the engine to the battery, no battery switches.

Probably have another 1.5' of battery cable tied up inside the battery area..

I should have clarified the statement regarding batteries positioned in console. Where you have an additional 12-20ft of cable. No idea if Yamaha offers an extended harness to run that length to the batteries. Probably charge a fortune for it.

[99yam40]

Power posts can be an issue. They are the first place I look now when having issues. They should be mounted on the side of the bilge. Not anywhere near the bottom. Terminals should also have protective covers.

I have not not heard of replacing the engine side cables with a straight run from battery. Google voltage drop testing to help narrow down the issue when it happens next time. I chunked a few dollars at the same problem and learned the hard way.

Put your meter leads directly on battery to get the exact reading. My dash guage is about 0.4 volts off as well.

I agree, OP needs to do some testing to make sure where his problem is.
no need to replace stuff that is not part of his problem
could be relay, switch,connection, or cable.
cables can go bad internally, but no need to replace if they are good

[fairdeal]

No idea if Yamaha offers an extended harness to run that length to the batteries. Probably charge a fortune for it.

I have not seen "Yamaha" battery cable extensions, although they have published a table of recommended wire gauge/length for them.

The "standard" cables are confusing enough:

there are, for example, 3 part numbers for 11.2 ft. cables;
one for 3.3L 2-stroke, one for 3.3L F200/225 and one for 3.3L F250

are there differences? if so, what?

Perhaps Boscoe will tell us.

[jupiter2360]

Thanks for replies. The yamaha dealer tech exchange bulletin #02014-002 dated 02/07/14 has comprehensive info and updated requirements on F8-F350 and 2.6 HPDI battery types, spec changes, and installation requirements covering battery cable extensions. I have the PDF but can't find the online link. Maybe someone could post a link to document as I found it when choosing my new wet cell batteries. I think the AGM spec change and rigging info is most relevant to this group.

[pstephens46]

Don't overthink this issue! Only Yamaha and other suppliers will benefit!

[jupiter2360]

To clarify I am not doing the rewiring to chase a gauge low voltage or rare no start condition. The rewire is due to a poor sailfish rigging setup that did not effectively isolate the starter batteries from house loads (in fairness note Sailfish ships their new boats without batteries and the local dealer installs batteries and cables) as well as the obvious poor quality of the cable rigging by the original rigger. Additionally I am try to get boat in excellent bulletproof condition to run hard and fast (as the Sailfish likes it) offshore with grandkids aboard and making a few summer Bahamas runs where any problems will take a lot of time and money to sort. While starting to cut and re-lug the cables I noticed the SAE cables. The cost of new AWG 1/0 is about $4.60 per foot for cable only.

Nearly all new boats seen at boat shows have power posts with batteries located in console. My power posts are conveniently and well located in the false transom wall about 4 feet above bilge ( a lot better than some boat manufactures I have seen with posts set low and difficult to access).

My main questions are:
1. Are two negative battery cables and/or two separate negative powerposts necessary or recommended for my T150 setup.
2. I know SAE cables are generally not ABYC or USCG approved but wanted confirmation/direction before spending about $400 to switch to AWG.
3. Are yamaha square gauges known for displaying inaccurate or low voltage as compared to actual? Is there a trouble shoot sequence if so?
4. Is soldering in addition to crimping lugs necessary when making up cable extensions (yamaha rigging guide and bulletin says it is and the factory OEM are soldered)?

Thanks again.