Replacing Iginition Switch

[FW0804]

I was in a hurry to make it up to the boat store before they closed and I forgot to note which wires were connected to the ignition switch before I disconnected it. How do I figure out which wires go where?

I have a 3 prong ignition switch. The 3 prongs are battery, start, iginition. The 3 wire colors are yellow-red, red and purple.

 

[Silvertip]

Re: Replacing Iginition Switch

Don't you think it would help if we knew what it was you were working on? We can only assume it's a boat -- but who knows what kind. And it would help if we knew what the letter markings were next to the terminals on the switch. If the terminals are not marked, do you own an ohmmeter and know how to use it.

 

[FW0804]

Re: Replacing Iginition Switch

The type of boat is a 1987 Four Winns with a 4cyl Mercruiser 165. The markings on the ignition switch and S I and B (start iginition battery i believe). There are only 3 prongs.

I do own a multimeter, and sorry if I sound ignorant - I am new to all of this and my knowledge of electrical wiring is limited.

Let me ask you this. When the old ignition switch was in place, I tested it and it was getting 12V but when i turned the key, nothing happened. To bypass it, I shorted out the solenoid and it clicked - this told me that the ignition switch was bad - again, im not expert - what are your thoughts on this?

 

[Silvertip]

Re: Replacing Iginition Switch

I'm betting the ignition switch was not bad and that the connections between the switch and solenoid were the issue. So -- check the small terminal on the starter solenoid and note the color of the wire. See if one of the three up front is the same color. If so, that wire goes to the "S" terminal. Check which of the remaining two wires has +12 volts on it. The red wire is probably the one. That is the input to the switch so it goes to the "B" terminal. That leaves one wire remaining so it must be the feed back to the ignition so it goes to the "I" terminal. If the wire color for the "S" terminal is not the same on both ends, veryify it with your ohm meter. Set the meter to the lowest ohms (resistance) setting. Touch the two test leads together to verify the meter is working. It should read "0" it its a digital meter. If it's an analog meter, as long as the needle moves you are good to go. Now then - touch one of the meter probes to the solenoid terminal, and the other end to what you think is the solenoid wire. You may need to add some alligator clips and a longer piece of wire to reach both ends of the circuit. If the meter moves or shows "0" you have identified the solenoid wire. DO NOT ATTACH AN OHM METER TO A POWERED CIRCUIT. In other words, identify the +12 volt "B" wire before doing any testing with the ohm meter.

 

[bruceb58]

Re: Replacing Iginition Switch

The type of boat is a 1987 Four Winns with a 4cyl Mercruiser 165. The markings on the ignition switch and S I and B (start iginition battery i believe). There are only 3 prongs.

I do own a multimeter, and sorry if I sound ignorant - I am new to all of this and my knowledge of electrical wiring is limited.

Let me ask you this. When the old ignition switch was in place, I tested it and it was getting 12V but when i turned the key, nothing happened. To bypass it, I shorted out the solenoid and it clicked - this told me that the ignition switch was bad - again, im not expert - what are your thoughts on this?

Could easily been your neutral switch in your shifter or your boat was in gear too.

 

[FW0804]

Re: Replacing Iginition Switch

Silvertip, thank you for your response. That makes sense I'll give it a try.


Bruceb28,
That's the other problem. When I bought the boat all of the uphostery was in the process of being redone, because of that the throttle handle was not mounted to anything so I can't tell FOR SURE whether it's in gear or not. I am pretty sure that I have it in neutral, i did this by watching the motor and making sure the two bars\levers on either side of the engine (for lack of a better word) for forward and reverse were in their neutral position.

Is there a better way to tell for sure whether the boat is in neutral or not?

 

[FW0804]

Re: Replacing Iginition Switch

Silvertip,

The ignition switch wire color matched up with the wire color thats connected to the solenoid. it still did not start with the wires hooked up properly, so i checked the wire harness. the solenoid wire is in pin position 7 on the wire harness and that connector is corroded..its a bluish color. im going to attempt to clean that off and see if that helps...but i am not sure if this is an indication that the harness needs to be replaced? Hope that makes sense...

 

[bruceb58]

Re: Replacing Iginition Switch

You have two problems...you want to make sure the drive is in neutral of course for safety sake...and you want the controller to also think the same so that the neutral safety switch is closed when you want to start. It is very possible for both of those not to be happening.

 

[FW0804]

Re: Replacing Iginition Switch

I cleaned the pins on the wire harness and the solenoid is now clicking but the motor won't start. Would this be happening if i was not in neutral?

I took a picture of the starter motor and solenoid. (at the time of the picture i had not changed or disconnected ANY wires) The guy had some wires disconnected when I bought it from him because he put in a new gas tank, so i have a feeling a ground wire is not connected to the start motor and thats why its not working but let me know your thoughts. see picture

http://i79.photobucket.com/albums/j154/rppalmer/IMG00088.jpg

 

[bruceb58]

Re: Replacing Iginition Switch

I cleaned the pins on the wire harness and the solenoid is now clicking but the motor won't start. Would this be happening if i was not in neutral?

No...it would not.


Why is there no nut holding on your battery cable on your solenoid?

There is no ground wire to a starter.

 

[FW0804]

Re: Replacing Iginition Switch

I knew it! I took the starter motor out last night to clean it out in case there was rust buildup. I got it to fire up by grounding to one of the screws on the starter housing.

There is a green wire that goes nowhere and i was wondering where it went. the weird thing (to me anyways) is that if i trace the wire it goes under the deck to the same place the fuel lines go. Is this the wire that needs to be hooked up or should the ground be coming from somewhere else?

 

[flargin]

Re: Replacing Iginition Switch

I knew it! I took the starter motor out last night to clean it out in case there was rust buildup. I got it to fire up by grounding to one of the screws on the starter housing.

There is a green wire that goes nowhere and i was wondering where it went. the weird thing (to me anyways) is that if i trace the wire it goes under the deck to the same place the fuel lines go. Is this the wire that needs to be hooked up or should the ground be coming from somewhere else?

The ground is a very heavy cable, similar in size to the Red one on your starter.

It is usually black, and likely black on yours, not green. The ground normally goes straight from the battery to a bolt on the engine. I don't know where on your model, but mine goes to a bolt at the back of the motor. They do not, and should not need to connect directly to the starter.

These connections must be tight and clean to work correctly. You should make sure they are clean and tight.

Green wire - No idea what that might be... but you should figure out what it is before you just connect it. I don't know of a standard use of green in mercruisers.

 

[bruceb58]

Re: Replacing Iginition Switch

Are you saying you had no large ground cable from the battery to the block?

 

[FW0804]

Re: Replacing Iginition Switch

Bruceb59 - There IS a black ground cable connected to the engine block.

And I think i misread your response, i thought you were saying there WAS supposed to be a ground cable to the starter - sorry about that.

And to answer your question, I think I might have taken that picture after I took the nut off.

I'm going to put the starter back in and make sure the connections are clean.

 

[bruceb58]

Re: Replacing Iginition Switch

It's also hard to tell from the picture but it looks like the screw is missing between the starter solenoid and the starter. Had you taken that off as well?

 

[FW0804]

Re: Replacing Iginition Switch

No the screw is there, it slides into a copper cylinder before screwing into the solenoid.

 

[FW0804]

Re: Replacing Iginition Switch

I don't get it. I hooked the start back up exactly as shown in the picture and all I hear is clicking when when I turn the key. I can get the starter motor to turn on on my work bench by hooking a jumper cable up to the starter and grounding it...this tells me the start works howerver, it's not turning on when I turn the key. Any ideas?

 

[bruceb58]

Re: Replacing Iginition Switch

What happens when you do a jumper from 12V to the start terminal on the solenoid?

 

[FW0804]

Re: Replacing Iginition Switch

I do know that during testing, we shorted out (1) and (2) (see picture)- would this have burned out the motor?

<a href="http://s79.photobucket.com/albums/j154/rppalmer/?action=view&current=IMG000882.jpg" target="_blank"><img src="http://i79.photobucket.com/albums/j154/rppalmer/IMG000882.jpg" border="0" alt="Photobucket"></a>

 

[FW0804]

Re: Replacing Iginition Switch

when i jump 12V to start terminal on the solenoid, the solenoid clicks, nothing else.