72 Thunderbird Formula w/twin 165hp Mercs

alldodge

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With no amp meter and only a volt meter, leave the wires together as before, just remove the voltmeter. Connect the voltmeter to the white wire, that is switched by the key.
 

Mark72233

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Just double checking what you wrote. Leave the two wires connected with each other just pull it from the gauge and run another jump wire from the white to each gauge
 

alldodge

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Just double checking what you wrote. Leave the two wires connected with each other just pull it from the gauge and run another jump wire from the white to each gauge

Yep'er that way it is turned on/off by the key.

You need the red and red/white connected so the battery is connected to the alternator.

In previous post I mentioned how to change the wiring in the engine but it was my understanding you did not do that
 

Mark72233

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No I didn't touch anything on the engine side because I thought you were showing directions for a 3 wire alternator and I have the one wire alternator
 

Mark72233

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I haven't had a chance to check the two wires (actually 4 wires in two bundles one bundle for each engine all 4 wires yellow with red stripe) coming from the shifter with an ohm meter yet but they should be the neutral safety switch wires. Assuming they are what do they get hooked to. The start switch connecting to the start terminal or the run terminal and why 2 wires
 

alldodge

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The neutral switch gets put inline with the yellow start wire. In the wiring drawing there is a tie spot. In you current setup you can start the motor in gear or out. The neutral safety switch goes inline so it will only start when the switch is closed in neutral.

Note, when in neutral there should be continuity between the two Ye//Red wires.

I would remove the yellow wire off the key switch and connect it to one end of the two Yel/Red wires. Then connect the other end to the key switch

neutral.jpg

Now here is something that can bite you. The original key switches were designed to handle some current do to the distance and not using a slave relay. So the issue is if your current switches can handle the current of full solenoid voltage. :noidea: would be good to know what the contact rating is.
 

Mark72233

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AllDodge I used the ohm meter and yes connected in neutral and breaks contact in forward or reverse no effect if I push the neutral throttle buttons for throttle only. So disconnect yellow and run it through these wires. I will check on the switches. I up graded the switches to these solid metal brass like Cole Hersee marine switches. Let me check to see if I can find a rating amount.
 

Mark72233

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Ok I got the port engine and port side shifter neutral wires all connected like AllDodge suggested and sure enough everything works like it's supposed to work. Volt gauge is on when key is on. Engine won't turn over if it is in gear. So I went and put about 8 gallons of fuel in the tank, another first and tried starting the port engine and after messing with it for an hour and not able to get a steady flow of fuel to the carb so it would only run a sec or two until it burned the gas I dumped down the carb. It could be float, fuel pump, air in lines since this is the first time I have had it hooked to the fuel tank. I have been running it with a long supply hose from the water separator into a 5 gallon plastic fuel can. It could be the tank pick up hose. After some thought the one thing I came up with was I have no cut off valves in the fuel line going to the starboard engine and those lines are all dry so it could be sucking air from that side instead of fuel from the tank, air is easier to pull through the lines after all. So I went and found a shut off valve in the spare parts department and after a little while of priming and cranking it finally cranked and stayed running but still seems to run a little rough. Changed RPM gauge to the right setting 6 instead of 4 cylinder so RPMs finally read correctly. I can idle it down to about 700 without it stalling. I let her run for a half hour, hour meter works. So onto re-wiring the starboard side and get it started. I will get some video of the engines running Saturday. Thanks again AllDodge
 

Mark72233

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Starboard engine is also running and all the gauges are working as well. Video of starboard engine running. I only have one muff so only one engine running. Last time I tried posting a video it didn't work. See if this time it does.
 

Mark72233

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I finished running all the wires even wire for future purchases light anchor light, radio, VHF, bottom machine is also wired just waiting on the 10 extension cable so I can play around with that. I also installed and wired a string of LEDs in the engine compartment and another under the starboard gunnel.

I also got the helm done and bolted in place.
 

sphelps

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Sounds great ! I know that's a nice feeling after all the work you have done ....
 

archbuilder

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Mark that sounds GREAT! I am looking forward to hearing my 6 do the same thing! the lights look great also! You are getting close to a splash!
 

Mark72233

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Thanks everyone I still have a ton to do. Next on the list is getting the windshield cleaned up and back on the boat. Might work on that tomorrow. Also still need to repair, prime and paint the dog box and 2 hatches for the cabin and the big one is the darn hydraulics which I still haven't touched.
 

mr300z87

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That must feel so good hearing and seeing the engines runs in the boat 😄😄. Great job on the wiring if I were closer definitely would come by to help but AD had you covered.

Mike
 
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