No spark 4.3 Mercruiser

[alldodge]

Clicks "LEFT", that's not correct.
Normal is first click RIGHT transfers Red/Purple to Purple. One more click right power is supplied to Yellow/Red for start

A 4 terminal switch would have one click left from the OFF position for accesories if used

 

[Bt Doctur]

accessory-center off - 1st position, ign on- 2nd position starter
left center off 1 click right 2nd click right

 

[Rick Stephens]

This switch, clicks once to the left for accessory. Middle is off, one click left is on and two clicks left is start. This is no position gives power to purple. Maybe it’s the wrong switch , basspro shop sold it to me, if it’s anything like the auto parts store I know these mess up sometimes.

With power wire connected, just put purple on the lug that goes hot with one click to the right and put starter wire (yel/red) on the one that is hot in the momentary second click right. I don't have an issue with an accessory spot, never seen that but be nice for the sterEEEEoooh.

 

[Wayneg13]

Clicks "LEFT", that's not correct.
Normal is first click RIGHT transfers Red/Purple to Purple. One more click right power is supplied to Yellow/Red for start

A 4 terminal switch would have one click left from the OFF position for accesories if used

This is how it was wired when I bought it. It’s click once left and twice right to start. Middle is off and you can take the key out. This is the new switch. I’m gonna move the wires around here because purple never lights up in any position.

 

[Wayneg13]

Scratch that lol. I noticed the new kill switch doesn’t work with the lanyard connected Took it off and two of the prongs now get power in the on position. I can start it now but the fuel pump doesn’t stay on. Seems like fuel pump is only on while cranking.

 

[Scott Danforth]

fuel pump is only on while cranking is normal. the other wire wont power the fuel pump until there is oil pressure.

 

[Wayneg13]

Scratch that lol. I noticed the new kill switch doesn’t work with the lanyard connected Took it off and two of the prongs now get power in the on position. I can start it now but the fuel pump doesn’t stay on. Seems like fuel pump is only on while cranking.

Double scratch that. I had the the universal kill switch hooked up wrong I guess. It’s marked “C” one way and “M” the other. Had it on C because I coulda swore I read that somewhere, switched to the M and it works normal now and gets power with lanyard connected.

 

[Wayneg13]

fuel pump is only on while cranking is normal. the other wire wont power the fuel pump until there is oil pressure.

Really? That’s super strange. It doesn’t wanna fire up now and is blowing white smoke out the carb after I stop cranking. I’m gonna try to run it again and see what happens.

 

[Wayneg13]

fuel pump is only on while cranking is normal. the other wire wont power the fuel pump until there is oil pressure.

Ok I had the ignition switch wrong. Fires up now and has about 42psi oil pressure according to this gauge but no fuel pump. Test light only lights up while cranking

 

[alldodge]

Your oil pressure switch should have 3 wires on it.
One goes to the fuel pump
One purple/yellow
One Purple

Also the key switch doesn't look right, what are the terminal letters on it?

 

[Wayneg13]

Your oil pressure switch should have 3 wires on it.
One goes to the fuel pump
One purple/yellow
One Purple

Also the key switch doesn't look right, what are the terminal letters on it?

I don’t see any other letters aside from these in the pic here

 

[Wayneg13]

Your oil pressure switch should have 3 wires on it.
One goes to the fuel pump
One purple/yellow
One Purple

Also the key switch doesn't look right, what are the terminal letters on it?

So. S, I, A and B and the four prongs. I got 12v contact on B, starter signal on S and “run” on I.

 

[alldodge]

OK you good on key switch, thanks
Now find the oil pressure switch

 

[Wayneg13]

Ok so I tested power at the beginning of the fuel pump circuit which is the starter, it powers up while cranking them turns off. Starter works just fine tho.

 

[Wayneg13]

OK you good on key switch, thanks
Now find the oil pressure switch

This oil switch has one wire on it but according to the diagram I saw “not sure if it’s correct” this one wire taps in to the purple/yellow power for fuel pump.

 

[alldodge]

That is the over temp switch, it closes when the motor over heats and sounds alarm

The oil pressure switch is most likely port side down by the remote oil filter connection. May also have the oil pressure alarm switch on a Tee, or it could be behind the distributor

 

[Rick Stephens]

My oil pressure switch to power the fuel pump is top back end of motor just to the rear of intake manifold and a couple inches port side of distributor.

 

[Wayneg13]

Sorry for so many posts. I found the “other” oil switch on the side of the block with two wires. Purple/yellow and purple. I’m think the issue is the power source from the starter. I just got my $90 service manual in and this diagram is the same as someone posted on this thread.

 

[alldodge]

with two wires. Purple/yellow and purple.

It should have 3 wires
If it starts and the pump does not run, then its the purple side feed and most likely the switch

From starter to pump during cranking from pur/yel to pump
From pur to pump once started

 

[Rick Stephens]

Mine only has two - so there are switches that have purple on one side and pur/yel on the other.

Wayne, you need to test the oil pressure switch. First, when the key is on run position, the purple wire should be hot. When the motor has oil pressure - and it only needs about 5 PSI - the other side (pur/yel) of the switch should be hot. SInce you say the motor doesn't continue running, the test is to connect both sides of the switch together and see if the motor keeps running. You are connecting the purple to the pur/yel. If this fixes the problem you need a new oil pressure switch.