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Mercury 40Hp Electric Starter Wiring Diagram

kickingbac

New member
Howdy all, I am looking to add an electric starter to my 1996 40Hp Mercury 2 stroke. I have found the starter and solenoid but need the wiring and set diagram to install. Any help would be greatly appreciated. My serial number is 0G331283.
 
If you don't get one it's not complicated. The large terminals go between the battery + (hot) and the starter insulated terminal...usually near the bendix...up mounted end. You will need 2 wires: One from the battery to the solenoid and a short one from the solenoid to the starter.

The starter ground (cold) is either by a band holding it in place, another screw on the case, or a jumper wire from a screw on the case to the battery -. This probably is a stud on the engine block then you can use the block for other cold wiring connections. If grounding to the block and the case of the starter isn't shorted to it, you will need a second cold wire between the block and the starter ground terminal.

You use wire large enough to carry the current. For 100 amps intermittent, which should be adequate to start that engine, and a short run, 4 AWG all the way for hot and cold. Your problem is getting terminals crimped on that wire. I know Lowes stocks wire and terminals. Do not know if they can crimp them too. If not possibly an auto parts store or a wire distributor. The colors are normally red for the hot and black for the cold.

The solenoid usually has 2 small terminals and usually it doesn't matter which is hot and which is cold. If it does, when you try to operate it voltage won't get to the starter. If so, just reverse them. If it only has one small one that's hot and the case of the solenoid is the cold so it needs to connect where the battery - connects via it's mounting bracket. Put a jumper wire on the bracket to a cold terminal if necessary.



The hot is simple also. All you need is a 12v min, 10 amp min. PUSH BUTTON (SPST momentary on) switch. Radio shack has them or an auto parts store. If you can get one water resistant great. Otherwise every so often it could fail due to water intrusion....but no big deal to replace it.

Wire the switch in series from 12v (hot connection anywhere) through the switch to the other small terminal on the solenoid. Wire size for this control circuit is 16 AWG min.

That's it.

Mark
 
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Thanks!! I'll try to make my own based on your expert advise!!!

Interesting term "expert advice". I made my living from 1959 till 2005 in the area. Was very successful and as a result am having a glorious retirement. Sharing my "expert advice" with you to help you out. Good luck,

Mark
 
graydonmcarthur...are you involved in this thread and working on this motor?

Texasmark explained it....kimcrwbr1 posted a wiring diagram thats about as simple as you can get...the only thing i disagree with is the ''momentary on'' thing on the switch to the solenoid pick....you need a switch that is on as long as you are activating it...if it is a push button it need to make as long as you press it and break when you release it...

your objective is simple..press or turn the key(which ever you use) and pick the solemoid...feed the starter through the heavy wiring and through the solenoid with the proper safety switch in the pick of the solenoid so you dont start in gear..
 
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