Kevin,Could you please tell me the best place to find an oddball boat wiring harness? I need one that will fit a Johnson 75elr78c engine from the red plug in the ignition switch?
Thank you for your help.
Hi Bill,
I’m sorry, but neither of our wiring sites have anything like this. If it were me, I would try ebasicpower.com.
Good luck,
Kevin
Kevin,
I recently bought a 16 foot Smokercraft fishing boat with a 60 hp Mercury EFI 4 stroke engine. I also bought a stereo unit for the boat and was hooking it up and now I have 3 problems.
- No power tilt and trim
- No turn over of the engine with the key start
- No power to my fish/depth finder.
I have checked the fuses. Both the one of the engine as well as the one on the fish finder.
I ordered a key switch unit and a 20 amp circuit breaker. If this does not fix the problem—do you have any suggestions of where I should look next?
All of the above worked before the stereo hook-up in which I connected the power cable to the ignition.
Thanks for your help!
Leroy
Hi Leroy,
There must be a blown fuse somewhere on your boat. Is there an in-line fuse at the key or an ignition fuse on the fuse panel?
I would use a meter or test light to look for 12 volt power at the key switch and make your way back to the engine.
I don’t believe a new key switch is going to solve the problem.
Let me know,
Kevin
Hi Kevin,
I screwed up my boat wiring and hope that you can help.
I have a 2004 Sylvan 18 I/O. I had to jump it the other day and in my hurry I hooked up the boat battery cables in reverse.
I have power to the bilge pump, boat horn and navigation lights, but the other side of the dash has no power at all. This includes starter switch, bilge blower, and radio. I checked the fuses but found none bad.
Did I miss a fuse down on the starter?
Thanks,
Maurice
Hi Maurice,
There is a push-to-reset circuit breaker on the engine that supplies power to the dash. It should be a red button about 3/8″ diameter on the stbd side of the engine near where the main engine harness plugs in.
Hope this helps,
Kevin
Kevin,
I have a 1994 Mercury 60HP two-stroke on a Bass Tracker boat. The boat wiring includes a push-to-choke ignition switch, which isn’t working.
When I apply a jumper wire to the choke (fuel enrichner) it works as should. With a voltmeter on the lead coming to the choke coming from the switch it reads 12 volts as soon as I turn the key to the on position but doesn’t trigger the choke , when I push in it still does nothing, do I have a bad marine ignition switch? It is a six pole.
Thanks,
Nelson
Nelson,
This is a common problem.
The jumper wire has great connections and doesn’t have a voltage drop, so…
Kevin
Hey Kevin
I have a 1970 25hp Johnson outboard, which is wired up to an ignition switch up from, pretty basic but the key ignition sprang work when its cold.
I rewired the whole thing using the same size and type of boat wiring, no improvement…so I talked with a friend of mine and he stated that the wiring should be set up differently with the power from the battery being directly run to the starter in a way I don’t really understand.
Do you have a schematic in electronic form that I could view?
Thanks Kevin!
Alex
Hi Alex,
Unless somebody has completely rewired your ignition system, I am sure it is already wired with a solenoid at the starter.
First I would have the battery checked. Second, I would check the boat battery cables that lead from the battery to the engine. Low voltage at the starter is causing your problem. If the battery cables have bad connections or the battery has a bad cell, the engine will be hard starting.
Hope this helps,
Kevin
Thanks Kevin,
It’s a brand new large deep cycle battery, but I will check the cables ASAP. They look ok but will check with meter.
Alex
Hi Alex,
Check the voltage at the starter when you are trying to start the engine.
If the cables are junk, they may still read good when no current is flowing. The true test will be when you are trying to start up.
Kevin
Hi Kevin,
I am helping a friend that has a 93 Sylvan Pro Select w/Console and a Mercury 115.
He unhooked ALL the boat battery cable connections without tagging the wires…and now he doesn’t remember what went where.
Can you direct me to a boat wiring diagram for this?
Thank You,
Don
Hi Don,
Sorry for the delay. It took some time to contact a friend of mine from Smokercraft/Sylvan engineering to see if such a diagram exists. Unfortunately, it does not.
As a rule, they used black as ground, red as 12v power, and orange as 24v power.
I would recommend tracing each battery connection back to its source before connecting it to the battery to be safe.
Kevin
Kevin,
I had to get a new ignition switch after hubby broke the old one. Then he didn’t tape and write on the old boat wiring what they went to.
Can you give me the colors and letters that go together? The new one that he bought has the letters, S, I, C, M, B, M…I’m not even sure he bought the right one!
Thanks for any help you can give me.
Tami
Hi Tami,
He did buy the correct key switch.
Here are the colors and letters.
Happy boat wiring,
Kevin
Thanks, Kevin.
The engine now turns over but the bilge, lights, etc. don’t work.
My old switch had S,C,A,M,B, and M, but no “I”…and hubby didn’t mark the wires. The switch even looks different. I’ve included a picture of the new switch with wires.
Please help! I love my boat and hubby wants to get rid of it, so he’s not doing much to fix it.
Tami
Tami,
The bilge pump, navigation lights, etc are either powered by a separate lead that has nothing to do with the ignition switch or an additional wire that would connect with the purple wire.
Check to see how the boat switch panel gets power and also check the ground. If all components quit, it is either the power or the ground for the accessories.
Kevin
Kevin,
I forgot to mention that the navigation lights, etc were working before I switched the wires to make the engine run – and it was all working before hubby broke the switch itself.
I just feel that something is either not connected correctly or we have the wrong switch. Did I wire it correctly? I was told somewhere else that the switch I have is for an I/O motor. Could that make a difference? Would switching the M and the MA make the difference?
Thank you so much for your help.
Tami
Hi,
An I/O switch will not have a choke, a mag, nor a mag ground terminal. You do have the correct switch.
Switching the M and MA will not make a difference. When you turn the key switch off, the M and MA posts are connected together internally to make the engine shut down.
Since all of your accessories have quit, there must me a wire left off either on the battery or the key switch. Is there an in-line fuse at the battery on a smaller wire?
Kevin
Kevin,
I fixed it!!! Yipeeeee….Thanks so much for all of your help!
My next project is to see why the tilt/trim doesn’t always want to work…..and then to learn to back the boat…that’s on my bucket list for this summer.
Thanks again…you’ve been a blessing!
Tami
Kevin,
I am installing four 12 volt batteries for a new motor in my boat. What size battery cables do I need to hook these in series?
Also, I am looking at boat switches from your partner site, EzAcDc, however I need to know if they snap into a the console panel, or do they need a box to be mounted into? If a box is needed do you know where to find them?
Thank you
James
Hi James,
The best way to determine the cable size is to use my boat wiring size calculator. Use the entire run as your cable length to calculate the correct wire size.
Our boat switches snap into a hole that measures .85″ x 1.45″. If the rear of the panel is completely exposed, I would recommend some form of protective cover. If used for DC, there is no requirement for a safety enclosure.
Hope this helps,
Kevin
Kevin,
Here is a boat wiring question for you:
What is this brown wire for and what terminal on the key switch do I connect it to?
I believe it connects to the key switch but I do not know which terminal to connect it to on the key switch
and what it is for. It goes to the motor and enters the motor near the spark plug. I am including three photo of it. One where it enters the motor (1962 40hp Johnson), one at the connection in the junction box, and one where it comes out near the key switch. Here is the link. They will be the last three photos.
Thanks,
Ted
Hi Ted,
The brown wire is for the water temperature sensor. It will connect to the “Idiot light” in your photo #4.
In theory, when the engine gets hot, the sensor on the engine head will complete the circuit and the red light will come on signaling an overheat. These rarely worked correctly 40 years ago. Every time you start the engine, make sure it is pumping water before your leave the dock.
Kevin
Kevin,
I have recently purchased a 1988 Alumacraft fishing boat with a 1996 15hp Johnson motor. This boat has electric start with a push-in choke, however the ignition was removed and all I have are the wires.
The wires are as follows:
- Yellow with a red stripe
- Black and yellow with a rubber boot
- Red
- Black
- Purple
- Purple with a white stripe.
Could you please help me by telling me what wire goes to what post on the boat’s ignition switch?
Thank you in advance for your help.
John
John,
Here are the standard boat wiring colors for your boat’s ignition switch.
Hope this helps,
Kevin
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