1985 120hp Johnson with voltage drop at ignition switch

My problem:
I have 12volts going into the ignition switch when the key is in off position. As soon as I turn in to accessories it goes down to about 3.5 volts when switched to accessories and then down to 0 when it is switched to on.

I have checked and fully charged two batteries to test this and always they read 12 volts.
I have overridden the neutral/safety switch.
There is 12 volts at the starter solenoid when the key is in off position but again goes to about 3.5 volts when switched to accessories and then 0 volts when in the on position.
There is no clicking or attempting to turn on when the key is turned on.
I have put jumper leads from battery to the starter motor and it turns over so the starter motor is not the problem.

I am in the process of purchasing a replacement ignition switch.
Is there potentially any other problem that could be causing this?

Thanks for any help given!

Re: 1985 120hp Johnson with voltage drop at ignition switch

if battery connections are clean and tight. there should be a red wire on battery side of solenoid that has a fuse sometimes get corroided may check that. someone else can give more ideas.good luck !

Re: 1985 120hp Johnson with voltage drop at ignition switch

Exactly, you have a high resistance somewhere between the battery and ignition switch. Oops, I take that back, it is somewhere between the battery and starter solenoid because you have the voltage drop there. (Um, is your voltage reading there at the big cable or the little white wire terminals? If at the little white wire, see my first statement) If at the big nut, it probably is right at the battery terminals. Remove them and clean them shiny bright and reassemble tightly. Don't forget the ground cable, it is part of the circuit.Could be a cable nearly corroded in two also.

If you don't find it, come back with specific location where you are reading the voltages. You are on the right track. Well that is till you started buying parts without knowing where the fault is.

Re: 1985 120hp Johnson with voltage drop at ignition switch

I had seen someone post on here with a similar problem which ended up being a faulty ignition switch. With my logic I had thought it may have been a faulty ignition switch, but I am certainly no mechanic! But are you saying it is not the ignition switch or unlikely to be the ignition switch?
Will get a chance to look at it later today and will see how it goes.
Thanks for the help!

Re: 1985 120hp Johnson with voltage drop at ignition switch

Before I started buying parts, I would do some voltage drop tests. Make sure and clean all cable connections and make sure they are tight as suggested by F_R.