Logo
FULL SITE MENU

Evinrude 35hp 2stroke 1988 key switch replacement. Wiring problems

M

MarkusH

New member
Its an outboard engine with remote control labeled OMC. I tried to replace the original ignition switch (pollak pat.5237133) with a Sierra mp39760. I thought it would be an easy thing to do but when i tried to start it afterwards i shorted the battery. I have been looking high and low for a wiring diagram but cant find any.

The connection points on the old key switch are labeled:
- A
- B
- C
- M
- M
- S

The connection points on the new ignition switch are labeled:
- I
- B
- C
- M
- M
- S


The colors of the wires in the remote control are:
- Red
- Purple
- Purple with white stripe
- Yellow with red stripe
- Black with white stripe
- Black with yellow stripe

The only thing i did different in the wiring is connect the one labeled "a" on the old switch, to "i" on the new one.
 
So i tried again today so i could try and understand the problem better. When ohming the battery plugs i get 5ohms when the ignition is on so the circuit is shorted somewhere. Is it possible to find the wiring diagram for this somewhere?
 
MarkusH said:
The connection points on the old key switch are labeled:- A- B- C- M- M- S

The connection points on the new ignition switch are labeled:- I- B- C- M- M- S

The colors of the wires in the remote control are:- Red- Purple- Purple with white stripe- Yellow with red stripe- Black with white stripe
- Black with yellow stripe

The only thing i did different in the wiring is connect the one labeled "a" on the old switch, to "i" on the new one.
Click to expand...

In your mind's eye... consider the "I" of the new switch to be "A"... and all will be well. Your post indicates you've done this and then you simply transferred the wires over properly<--- Apparently you have not. They should be as follows:

- I - Purple
- B - Red
- C - Purple w/white stripe
- M - Black w/yellow stripe (post of this "M" terminal is usually a raised post)
- M - Black w/white stripe
- S - Yellow w/red stripe
 
MarkusH said:
Thank you very much. I will check this as soon as i can and post the results.
Click to expand...

To add to Joe's post

You can test your key switch to check that:

In the "Off" position there is continuity between M and M. This grounds the ignition to stop the motor

In the "Start" position there should be continuity between B and both A(or I) and S

In the "On" position there should be continuity between B and A (or I)

When the key is pressed in to operate the primer/choke, in the start or on position, there should be continuity between B and C.

You should have tested the old switch before buying a new one to be sure that is was defective or you may have wasted beer tokens unnecessarily .
It would be a good idea to check the new switch in case shorting the battery may have damaged it although the fuse should have blown and prevented this

There are wiring diagrams , although not specifically for your engine, in the manual on the Boatinfo website ( sorry Marine Engine will not allow a link). This is in fact the Seloc manual which you can buy from Marine engine
 
Last edited:
I tried once again yesterday with a new battery and its wired the way you said. I could hear a 'tick' from the starter but it wouldnt go around, after a couple of attempts the wires got real hot and melted together. Im thinking the circuit is either shorted somewhere or the battery might be too small as the old one was 115amps and the new (not exactly new i took it out of an old volvo) is 65amps.
 
If the ignition switch is wired as it should be... one of the wires (or more) is wired incorrectly at some other point OR the ignition switch is shorted internally.

You're be required to check/trace the continuity route of the switch with "all" wires disconnected... and the wires from the switch area to whatever they're supposed to be attached to on the powerhead or wherever.

Question: The two halves (male/female) of the main electrical connector at the engine should be of the same color. Are they?
 
Yes they are the same.

I might aswell tell you the whole story;
I got the boat out of the ocean and it started on the first attempt. So icleaned it, painted it etc and put it out in a lake instead. When i tried to start it it seemed like the battery was dead, turned ouy i had switched the - and + when connecting the battery, so i switched it back but there was still no response except for the 'tick'. I thought i had broken the battery and switched to another (65amps instead of 115amps), when i tried to start it again i realized i had broken the ignition switch so i ordered a new one. While waiting for a new ignition i took the starter out and had it tested at a local shop to rule out any fault there, and it worked. When i got the new ignition i wired it as you said and put the starter back in, with a new battery, ignition and the starter tested i was sure it woulf start but the wires from the battery to the engine went red hot and melted together.

Since it started on the first try before i started to mess with it im thinking i did something wrong when i took the starter in and out or that something broke when i switched the - and +.

Sorry if its hard to read, English is not my first language
 
Back
Top