58 Johnson 35 Mercury Switch Smoking

[timmeraw]

I am having a starting issue with my 58 Johnson 35. It is electric start and is intermittent in starting. Part of the problem is my lack of a good strong battery but I have been getting by working on the motor with a couple of older ones that take a charge but not for long and I sometimes even jump one with the other.

First issue was electronic choke stopped working. I seem to have fixed it by running a ground from small left terminal on the solenoid(in the Solenoid box) to ground on battery.

Second issue is that I am seeing some smoke(and now charing) on what I believe is one of two small silver mercury switches(neutral safety cut off right?) that are attached to the throttle arm. As in...if the throttle is rotated past the start position to far in neutral it wont allow start.(yes I have to adjust my throttle on controls a bit). But what is causing the smoking when I try to start? I believe that the solenoid is grounded thru the mercury switch...is that correct?

ANy ideas are greatly appreciated.

Thanks,
Tim

 

[Chinewalker]

Re: 58 Johnson 35 Mercury Switch Smoking

Only way that could be smoking would be if you had 12V going through it. Double check your wiring...

 

[timmeraw]

Re: 58 Johnson 35 Mercury Switch Smoking

View attachment 115935

I needed to use the original ignition switch out of this boat to put into another with an older Evinrude that had no key. I replaced the key and recently rewired this one back in for the Johnson. I may have wired something wrong. When I removed it I only documented it with a couple of pics. as you see above.

I think that the following wires are:
- the thin red one at the bottom is for horn power and it is connected on the same post as the double wires(one red from choke button These are both on the post reading Battery.
-another grey runs from harness to second post on Choke
- the two opposing black wires are on the M mag posts
- the yellow is on S and runs to Solenoid.

What I don't get is that without the ground wire I placed from small left(motor side) terminal on Solenoid to the ground on the battery...I get nothing...no electronic choke and no start, clicks anything. ALso....according to this wiring diagram at end of this manual...the choke solenoid has the red wire coming from the button and is grounded. How is it grounded? There is only the one wire connection ...is it thru its body clamped to the block?
http://www.agott.com/glassboat/Manuals/Johnson2m.pdf

I am also referencing this ignition diagram: http://continuouswave.com/whaler/reference/ignitionSwitch.html

Here is a picture of the wiring on the starter solenoid:

 

[lindy46]

Re: 58 Johnson 35 Mercury Switch Smoking

The gray wire from the choke button goes directly to the one choke solenoid terminal. When you press the button, 12 volts is supplied to the solenoid. The choke grounds as you said, through the solenoid body. It shouldn't be connected to the starter solenoid. The tan wire coming off the small starter solenoid terminal next to the large terminal going to the starter, connects to a side post on the cut-out switch. The mercury switch also connects to the side post of the cut-out switch, and the other wire grounds to the motor. The mercury switch keeps the starter solenoid (and thus, the starter) from firing if the throttle is advanced too far. It is a normally closed switch until it gets tilted when you advance the throttle. If that mercury switch goes bad, the starter won't fire.

 

[F_R]

Re: 58 Johnson 35 Mercury Switch Smoking

If you (or somebody else) have put a Ford Solenoid in the junction box, it will smoke the mercury switch bad. In fact, it will probably burn the wire off.

Choke button sends 12V to the choke solenoid. Ground is through the case

Key start switch sends 12V to the starter solenoid. The other small terminal on the solenoid connects to the mercury switch. The pull-in coil in the solenoid is between those two small terminals. The mercury switch completes the circuit, "clicking" the solenoid to energize it. (That is NOT how a Ford solenoid works).

The 1958 mercury switch is a dual unit. One unit is for the starting, and the other is to complete the ground return for the vacuum cut-out switch. The start solenoid is NOT connected to the vacuum cut-out switch for 1958.

 

[timmeraw]

Re: 58 Johnson 35 Mercury Switch Smoking

Thanks Lindy and F_R for the thoughts. While I digest your info here is what I believe is the correct wiring diagram that I just found and will use to trace things down. One thing F_R.... the solenoid was original and the only thing I switched out was the ignition switch as I needed for some other motor(61 Evinrude 65 I think) that didn't have a key and I wired that switch back in to this application recently when I ordered a key for it. I only tried a different starter solenoid when I was having issues and it was out of an early 60's Evinrude and is the same from what I can see(not automotive)

View attachment 115975

 

[F_R]

Re: 58 Johnson 35 Mercury Switch Smoking

Here ya go....

 

[timmeraw]

Re: 58 Johnson 35 Mercury Switch Smoking

Thanks for the wiring diagram F_R......same one I attached in my last post(though came out as a link and not a thumbnail like yours).

 

[timmeraw]

Re: 58 Johnson 35 Mercury Switch Smoking

Ok a user on another forum assisted me..... It is indeed a ground issue. I used a jumper cable to ground from starting battery directly to the power head. I removed my little ground wire from solenoid and I knew I was in business as I immediately had electronic choke working and it fired right up.

Now to find the problem. According to the wiring diagram there should be two grounds at the engine. The large stainless braided strap "ground to power head".
What I don't see is the ground from the wiring harness adapter to the "lower motor cover" as indicated??

 

[timmeraw]

Re: 58 Johnson 35 Mercury Switch Smoking

I checked, dismantled, cleaned to a shine, replaced and checked again everything I can from key to engine. I just finished tearing the starter off, and taking the internal wiring harness apart to verify that indeed it appears that the ground is supposedly happening thru the screw/outside harness head to the lower motor cover. I cleaned all adapter posts etc while I had it apart. Put it all back to together and still a ground issue. It has to be simply that the motor(cover/block etc) is not getting grounded to the battery because it is fine when I jump it directly from starter bracket bolt to battery neg.
AND...I just proved it: I took my little ground wire I had made up before and connected one ring terminal on the wiring harness adapter tightening screw(between the harness and the lower motor cover and connected the other end to a starter bracket bolt and Whalla...grounded and functioning.

Guess I will have to make that permanent cause I don't know what else to do to get that grounded properly.

 

[lindy46]

Re: 58 Johnson 35 Mercury Switch Smoking

Make sure your connector on the side of the motor is good and tight - and that tightening screw you mentioned is clean and shiny and making good contact. Use an ohmmeter to track down lack of continuity on various ground points. That ground wire from the starter could be corroded internally causing the problem, so maybe your jumper wire is the solution.

 

[timmeraw]

Re: 58 Johnson 35 Mercury Switch Smoking

Lindy,

I have made sure that the connection is both tight and shiny cleaned up. I ran the short ground wire from the screw to the block and all is fine...albeit a bit funky looking with a wire running from outside up under the cowl but working and problem solved which is all good.

Thanks,
Tim