1962 75HP Electric Shift **NEED MORE HELP!!!**

[newfiez]

Hey guys,

Working on a 1962 75HP Johnson V4 (model V4AL-14). I just had the unit fully rebuilt in the spring, and the boat ran fine all summer.....until now. It seems that when you are in fwd or rev, the unit tries to engage the other gear at the same time, and stalls the engine. I disconnected the wires, and ran Battery+ directly to the lower unit (one gear/wire at a time) and the problem went away. So I measured the voltage at the knife connectors from the wire harness at the back of the engine (disconnected from the lower unit):
? Ignition ON, shifter in FWD position: green wire 11.7v, blue wire 5.5v

? Ignition ON, shifter in REV position: green wire 5.8v, blue wire 11.7v

? Ignition ON, shifter in NEUTRAL position: 1.0v on either wire?

From there I checked the switches in the shift box, and they worked properly. Then, checked the wiring in the main junction box at the back of the boat. Disconnected the connector in there for the shifter, measured the blue and green to ground when a shift was selected...got 0v on one while getting 11.4 on the other. Hooked them back up, and measured right at the connector, back to getting 5v on the opposite wire (even with the wires disconnected at the back of the engine to the lower unit). How could I possibly be getting power on the opposite gear that is selected?

Anyone have a wiring schematic for this???

 

[F_R]

Re: 1962 75HP Electric Shift

Re: 1962 75HP Electric Shift

From your description, it would appear that you are getting some leakage between the blue and green wires somewhere between the plug in the junction box and the knife connectors at the motor. My first suspicion is right at the plastic plug in the junction box. Got any corrosion or contamination in the cavities?

Actually, you should check the voltage at the knife connectors while still connected. That will load the circuits and prevent false voltage readings that can occur merely from dirt or moisture in an unloaded circuit.

 

[newfiez]

Re: 1962 75HP Electric Shift

Re: 1962 75HP Electric Shift

From your description, it would appear that you are getting some leakage between the blue and green wires somewhere between the plug in the junction box and the knife connectors at the motor. My first suspicion is right at the plastic plug in the junction box. Got any corrosion or contamination in the cavities?

Actually, you should check the voltage at the knife connectors while still connected. That will load the circuits and prevent false voltage readings that can occur merely from dirt or moisture in an unloaded circuit.

I got the same readings at the knife connectors. I replaced (spliced in) a portion of the wire bundle a few years ago because some sections of wiring were rotten, and the wires at the connector going to the back (knife connectors) were 2 of the wires that were spliced. Maybe there is more rot but further down, and the wires are leaking in there? I'll try a set of jumpers from the connector, right back to the knife connectors and see if that isolates the problem.

 

[Daviet]

Re: 1962 75HP Electric Shift

Re: 1962 75HP Electric Shift

Why don't you run new wires from the control box to the knife connectors and eleminate all the bad wires?

 

[newfiez]

Re: 1962 75HP Electric Shift

Re: 1962 75HP Electric Shift

If the jumper fixes it, I may just do that

 

[newfiez]

Re: 1962 75HP Electric Shift

Re: 1962 75HP Electric Shift

Ran a new harness from the junction box to the knife connectors at the lower unit. Now everything is working correctly!

 

[newfiez]

Re: 1962 75HP Electric Shift

Re: 1962 75HP Electric Shift

OK,

So now the guy tries to use the boat today, and he can't get it into either fwd or rev without the engine stalling. I checked it out, when you start the boat, the prop is slowly spinning in neutral. When I put it in fwd it stalls. I bump up the throttle and try again...it runs fwd for a few seconds then stalls. When I put it in rev, the boat goes in fwd? Even when I disconnected the two wires going to the lower unit, and try one wire at a time, it still stalls. It seems to me that the unit is stuck in fwd? What do I do now??

Thanks,

Jimmy

 

[F_R]

Re: 1962 75HP Electric Shift

Re: 1962 75HP Electric Shift

If you don't apply ANY 'lectric to either wire it is in neutral, right? (It should be)

I gotta say the two wires leading to the lower unit are shorted together somewhere. It probably was the original problem.

 

[newfiez]

Re: 1962 75HP Electric Shift **NEED MORE HELP!!!**

Even with the power disconnected, and the engine running, the prop is slowly turning. So it's possible that the wires going down the unit are shorted? So I guess I have to pull off the unit and see

 

[newfiez]

Re: 1962 75HP Electric Shift **NEED MORE HELP!!!**

Just an update to this...the wires in the unit were shorted...just waiting on a new harness to replace it and see what happens

 

[yorab]

Re: 1962 75HP Electric Shift **NEED MORE HELP!!!**

Keep in mind that one of your electromagnetic shift coils could be shorted as well. Do you have the gearcase opened up?

 

[newfiez]

Re: 1962 75HP Electric Shift **NEED MORE HELP!!!**

After I found the short, I gave the unit to the shop I buy my parts from...they rebuilt the unit in the spring (minus the harness), so I gave it to them to fix because the remainder of the unit was under warranty and I didn't want to void it in any way. They've worked on this type of unit hundreds of times, so I'll let them fix it and see what happens.