f150 won't start on just 1 battery

[panasonic]

Thanks for answering my question.

I have attached a picture of the inside of a outboard motor starter solenoid which would be similar to yours. This person was having problems getting his outboard to turn over and it was corrosion in the solenoid contacts.

The test you done showed "continuity" across the two main lugs on the starter when you put power to the brown/white wire and starter case. And the Bendix thru out as normal. This is good. But that doesn't mean there is good corrosion free contacts in there.

Starters by their very nature have a very high initial current draw from the power source, then it falls off sharply as the engine begins to turn.

IF the solenoid contacts are corroded and you try to pass a large current through them, the resistance goes through the roof and nothing happens or it turns very slowly. BUT when you have two fully charged batteries turned "on" you may have enough current available to overcome this resistance and the starter turns over. Corrosion in electrical systems can cause strange things to happen.

This maybe a possible explanation of what is happening.

I am just as puzzled as you why one battery wont turn that engine over, but two will.

[gsdanno1]

So after all the tests I'm to the point of "buy it and hope it fixes the problem " ?

[panasonic]

So after all the tests I'm to the point of "buy it and hope it fixes the problem " ?

Danno,

Can you hook that starter up as shown in the attached picture and measure the voltage drop across the solenoid lugs when the starter is engaged and under load? Using a set of jumper cables and not the cables in the boat.


You may have already done this, I looked back through the previous posts but I am not sure.

[gsdanno1]

I couldn't make myself believe it was the starter , so I took my test results and starter to a local mechanic this morning , and before I could finish my story he said , replace all the battery cables ,and your problem will be solved . I didn't really put a lot of stock in that since he wouldn't take the time to let me show him all the results , so I took the starter to an auto electric place about 25 miles away , explained to him the problem , showed him all the results , and he said the same thing > I had him load test the starter , which came back fine . I then purchased 2 -3" sections of 4 gauge marine battery cable . I took one of my batteries out , hooked the cables to the starter , touched the brown/white wire to the positive terminal , and it started right up . I then hooked the brown/white wire back to the boat , turned the key , started right up . I guess my jumper cables are garbage as well .Glad it's not the starter due to cost , but it's going to be a real pain to pull all new cables ! Thanks again to all , hopefully I will be able to leave you all alone for awhile . Last question , will 4 gauge be sufficient , I think my longest run will be about 6'-8'

[99yam40]

I would use the same size that is in there or larger just in case.
start at the ones from battery to the switch, you know the ones from the switch to motor should be OK since the both position works.

Most people have junk jumper cables. I make my own out of welding cable. you can make as long as you want, even jump a car off from behind if you want to store that much cable

[TownsendsFJR1300]

You should be able to bolt/zip tie etc the ends of the old cable to the new one and simply pull it thru...

Glad you found it...

[panasonic]

I couldn't make myself believe it was the starter , so I took my test results and starter to a local mechanic this morning , and before I could finish my story he said , replace all the battery cables ,and your problem will be solved . I didn't really put a lot of stock in that since he wouldn't take the time to let me show him all the results , so I took the starter to an auto electric place about 25 miles away , explained to him the problem , showed him all the results , and he said the same thing > I had him load test the starter , which came back fine . I then purchased 2 -3" sections of 4 gauge marine battery cable . I took one of my batteries out , hooked the cables to the starter , touched the brown/white wire to the positive terminal , and it started right up . I then hooked the brown/white wire back to the boat , turned the key , started right up . I guess my jumper cables are garbage as well .Glad it's not the starter due to cost , but it's going to be a real pain to pull all new cables ! Thanks again to all , hopefully I will be able to leave you all alone for awhile . Last question , will 4 gauge be sufficient , I think my longest run will be about 6'-8'

Well that is good news you don't have to replace a $500.00 starter. Take them jumper cables and throw them in the garbage where they belong.

[panasonic]

Here is a pretty good video of how to make up battery cables.

https://www.youtube.com/watch?v=mOZeKG5j5TE

[boscoe99]

A properly performed voltage drop test should have clearly indicated a voltage drop problem in the cables.

I am wondering if the test was performed without the starter motor being energized by the starter switch?

[pstephens46]

Still curious...Where is the power post/ junction block you described on page one?

[gsdanno1]

power posts are in the bilge . all they are is a connection point so any accessories from the engine , or items like a power pole etc. , don't have to be run all the way back to the console where the batteries are. Correct volt drop tests were performed , as I revisited the results last night and early this morning it made me question the starter being the culprit. I'm going to run 2 gauge all the way from the batteries to the power posts. The cabling from the power posts to the engine are the factory Yamaha cabling and check out fine. as I pulled out the battery cables this afternoon , I saw where from the switch to the batteries was 6 gauge , and from the switch to the power post appears to be 4 gauge .Really poorly wired , don't know if that was a Scout issue , or if that was a dealer issue. Going to solder/crimp/heat shrink connections

[pstephens46]

power posts are in the bilge . all they are is a connection point so any accessories from the engine , or items like a power pole etc. , don't have to be run all the way back to the console where the batteries are. Correct volt drop tests were performed , as I revisited the results last night and early this morning it made me question the starter being the culprit. I'm going to run 2 gauge all the way from the batteries to the power posts. The cabling from the power posts to the engine are the factory Yamaha cabling and check out fine. as I pulled out the battery cables this afternoon , I saw where from the switch to the batteries was 6 gauge , and from the switch to the power post appears to be 4 gauge .Really poorly wired , don't know if that was a Scout issue , or if that was a dealer issue. Going to solder/crimp/heat shrink connections

I think the 2 gauge is a good idea.

I have the same bilge situation in my boat and those connections created starting problems for me. Couple other people on this website too. Oldmako comes to mind. I wonder if we should hose that thing down with boeshield or some other spray periodically? And I am not sure about using solder on those big connectors? I would try to find the highest quality copper connectors and use shrink tube to cover them. Lots of current.....

[Reel Kahuna]

I bought a battery crimper like this and used my 12 ton Hydraulic press to crimp the lugs. Worked great.