TOPIC: '61 Merc 500 Ignition Switch Wiring

Hi all,

I recently picked up a '61 Merc 500 that had no controls. I have what I believe is a compatible wiring harness(cobra end (2 large and 5 small connectors) but it was cut out of the original control box. I am trying to wire up a keyed switch to it but am having some issues. I have the following 6 colored wires in my harness"
1. Black
2. Red,
3 Blue
4. White,
5. Green
6. Yellow


Can someone help me to correlate the colors(referencing this wiring diagram : www.maxrules.com/oldmercs/Wiring/0_1965a/4.pdf

with the 6 Posts on the switch. FYI... the switch is push to choke(and specific for magnito starting. The posts are labeled--with instruction verbage below....and my assumptions of colors which are not correct.

Posts Color I Connected
M- Gnd

---

black(F in diagram--goes to rectif)
B - Battery +

---

green
M- Magnito Circuit

---

white
C- Choke

---

blue
I- Ignition Circuit

---

red
S- Soleniod

---

yellow

I thought I had it figured out but when I connected to battery it was sparking and only thing that kinda tried to work was the push choke solenoid. I am not sure what is being described as
the "Ignition Circuit" and "Magneto Circuit"

Thanks.

I think I found the answer in iboats.

Switch...............Engine harness
1966 pre-1966(mine)
B........................red green
C........................grey Blue
S........................yell yellow
M........................blk red
M........................Salmon white
I.........................white black
Brown to front 3 prong connector

UPDATE: Yep...working like a charm. Now to get it to
keep running. I'll be starting a new thread on that issue I'm sure.

Glad you got that sorted out Tim.

Thanks Mark.. i'm glad I got it figured out without ruining something having it wired incorrectly.

Now I need to get it fully awake and running. After I got the harness working I managed to get a few cranks before the battery died. It definitely has spark and roared to attention with some premix in a couple of the cyls but it quite after a couple of seconds.

So far I have removed the mag and cleaned/set the points and contacts, removed and cleaned both carbs replacing gaskets, needle-seat, etc from the carb kits, removed and cleaned the fuel pump and replaced gaskets and diaphram etc., and while I was at it replaced the fuel lines. I will need to double check the way I put the fuel pump back together....I assume that the diaphram can only go one way?

When battery charges I will be back at her.

Have a great weekend.

Tim

i'm glad I got it figured out without ruining something having it wired incorrectly.

Me too, that was my first thought - hoping something else wasn't damaged with the sparking you were talking about. So many horror stories about wiring issues lately knocking out other stuff in the system!

I've got the -65 Merc manual, if you need me to look up the fuel pump info give me a shout. Glad to help any way I can, Tim.

You have a great weekend too, I'm back to sanding on the GT......

Thanks Mark... I guess the pre-CDI ignitions are pretty hardy in that regard.(besides crossing the battery cables and frying the rectifier).

I actually have a good Mercury Service Manual for outboards 1965 and prior....though the section on the fuel pump was not exactly like mine and I found my answer looking at a picture on Crowley Marine. In any case I had it correct and it is running great.

See my other post here about issues.

Good luck with your sanding and your GT..is it the Bond Boat?

Sometimes even the Merc manual has pictures and descriptions that are a little off, I guess they're covering a variety of years and production changes, so it's bound to happen once in a while even to them.

I saw the other thread, pretty nice little motor! I'm trying to do better about letting the guys and gals who really know give the advise, I'm still a rookie compared to them.

My GT 150 is a '71 (first year for that model), I think it was a '72 in the movie. I got it 'cause I love the lines and style of the boat, many of the "new" features carried over into other Glastron and Carlson models, and other brands for that matter for years after that. It's my first "major" project, so we'll see how it turns out! (what they're supposed to look like - not mine) (my project in progress)

It's looking real good Mark.