TOPIC: mercury control compatibility

Sorry if this should not be posted here and i searched extensively before posting.

I have a Mercontrol control and a Quicksilver control. I want to use the Quicksilver control with my 1959 Mark 35a. Can i use the wiring harness from the Mercontrol on the Mark 35a?

I feel this is a no-brainer but i had someone stop by and he said it would not work. He said the plug "prongs" wouldn't match up to the Mark 35a but i checked and they do.

Harness is shown below......


Using this control......did this control originally have any buttons or key cylinders? If someone has pics please post.

that plud should work in a 35A may not use all the pins. if it plugs in it should work.

If the plug fits, it should work. However, getting the harness to work with the older controls may be an issue, as the original key switch had a right-angle harness that allowed it to fit on the face of the control box. The MerControl key switch is likely too deep to fit in the box. Might have to dash-mount it, or find a different key switch that will fit...

Good to hear since the ignition and choke switches are mounted on the dash

Just be sure and carefully review the wiring diagram for the Mk35A and the wiring diagram for the early '70s MercControl's wiring harness as the colors are different.
Since you don't already have the electric start harness & correct side for the older (2) lever control box to have an ignition & choke, the simplest solution is to do a dash mount, like Scott (Chinewalker) suggests.
A push-to-choke ignition is a real slick way to go, but it sounds like you already have some sort of dash mounted ignition & choke system.
If you choose to go to a push-to-choke ignition, I prefer using the Sierra Marine # MP41070-2 (available through NAPA)
If you need assistance with the wire color coding, please write direct as I am rarely able to sit and enjoy the forum any more.
Yes,...I 'should' be sleeping at this hour (3:56 am PST) but pain free sleep doesn't come easy these days.
Thom (Doc Frankenmerc) frankenmerc at comcast dot net

I tried to email Dr_Frankenmerc for help on the wiring of the Mark 35A but email didn't go through. Can anyone else help me out?

I think this should be the prong for the choke.....

This prong for the positive cable....

Negative cable.....

Here's where i'm having problems. I'm using an ohmmeter to figure out wiring but this prong is getting a reading at the magneto AND the red square thing that i believe might be the rectifier. What is this prong actually for?

I'm getting a reading at the magneto AND at the solenoid. What is this prong actually for?

The last prong gets a reading at the square thing near carbs. Is this the rectifier? I thought i got a pic of it but didn't...i'll post pic of it in a bit.

Hi,
Starting with the last picture, the small center pin does connect to the battery-side of the rectifier.
Second picture up, small lower left pin does connect to the magneto assembly terminal for grounding the breaker point to stop the outboard.
Third picture up, small upper left pin connects to small terminal on starter solenoid (other small terminal connects to ground, if the correct solenoid is in use). Start circuit
Fourth picture up, large lower pin does connect to large engine ground cable.
Fifth picture up, large upper pin does connect to (one of the) large terminal of the starter solenoid.
Sixth picture up, small middle left pin does connect to choke solenoid.

Regards,
Joe
www.fergusonpoolemarine.com
This email address is being protected from spambots. You need JavaScript enabled to view it.

P.S. My very best to Thom!

Thank you sir!

Does anyone have a wiring diagram for the mark 35a?

I'm not familiar with the rectifier and am a little confused about what wires go where out of the motors harness (to key/ choke/ etc).

This is where i'm at now...
A to choke switch
Choke switch to choke solenoid

S to solenoid at motor

Positive cable to battery positive

negative cable to battery negative

I don't see any cut-off switches and only see one wire coming out of magneto. So that's where the confusion comes in, where do the magneto and rectifier wires go to after leaving the motor and do i use the 5-pole switch or switch to a 3-pole? If so, what hooks to the "M" and "Bat" terminals?

If pics will help i can post some.

anyone agree with this?

Positive out of harness to battery positive...
Negative out of harness to battery negative...
Choke out of harness to push choke then from push choke to ignition "A"...
Solenoid out of harness to "S"...
Rectifier out of harness to "BAT"...

That leaves me with 2 "M" terminals at ignition switch that i'm not sure how to wire to the single magneto wire in the harness to motor.

Ok, i think i got it. I have a wiring diagram and it appears i need a 5 pole switch.

i know this is an old thread but i was wondering if you could post up that wiring diagram? thanks!