1995 Mercury 40 hp 4 cylinder ignition problem

[Starcraftguy1]

Ok,I got to the lake yesterday,taking the boat off the trailer.I turn the key,nothing.I keep the battery chargers on 1 amp for three days.It seemed to me that it was not in nuetral.plenty of juice in the batteries.I knew that my buddies where somewhere on the lake ,so I used the trolling motor to hit a couple of spots while waiting for them.They showed up and we switched out the batteries.Still nothing with the key.So,we jumped the starter with another battery,and it started right up.But,if you turned it off,nothing with the key.But,when you jumped it by the starter it ran perfectly.I trailered it up and went home.Nuetral and everything is in the proper place.Is it the ignition switch,or is there a relay for nuetral that might have went out.But,with the key the starter gets no juice at all.Just wondering if anyone has any ideas before I start buying unnecasary parts.Thanks in advance.Bruce

 

[CharlieB]

Re: 1995 Mercury 40 hp 4 cylinder ignition problem

There is a main fuse on the motor somewhere between the main positive battery cable and the wire harness.

Find it, I'll bet that it is blown.

If you inadvertently switched battery cables, even for a heartbeat, when reconnecting the battery, you toasted that fuse, AND probobly the rectifier also.

Once you change the fuse and the motor starts correctly, take along a digital volt meter and check the battery voltage before starting then again while you are running, you want to be sure that the charging system is still operating.

 

[Starcraftguy1]

Re: 1995 Mercury 40 hp 4 cylinder ignition problem

Well,I have never removed the the battery cables,only after this problem started.I have the chargers that just plug into existing cables that stay on the battery bolts.The charger justs plugs onto them cables.We checked the main fuse on the lake,there was an extra one there and we changed it,just in case.Could the rectafier go bad during charging?Or anything else that would not let you start the engine with the key,but be able to start it by jumping the starter?

 

[Barnacle_Bill]

Re: 1995 Mercury 40 hp 4 cylinder ignition problem

Find the yellow/red wire on the starter solenoid and check for 12V there while someone tries to start it. If you have 12 V there, replace the solenoid, If not, test your ignition switch. Make sure you have 12V going to it on the red wire and 12V coming out on the yellow/red wire when you try to start it. If that is good then there is a problem with the yellow/red wire somewhere.

 

[Starcraftguy1]

Re: 1995 Mercury 40 hp 4 cylinder ignition problem

Thank you guys,I will try all tomarrow.I will be back with a post tomarrow night.Very much appreciated.This site is the best

 

[Starcraftguy1]

Re: 1995 Mercury 40 hp 4 cylinder ignition problem

bhile,that was it.The solonoid,I put in a new one,and start she did.Thank you very much,All is well,here in Arizona, now