help with an 5 Pole Ignition Switch..

[bebeard]

Good Day All,

I am trying to troubleshoot a wiring issue with my accessories wiring on my 1977 Challenger with Merc 1500 outboard. I wanted to know if with the attached diagram you can tell me what pole/colour wire coming from the ignition switch and or wiring harness controls the accessories (gauges, lights, etc). The reason I am asking is that I am trying to troubleshoot a short causing my fuel gauge to show "Empty" when the ignition switch is in the ON or Start Position?

Thanks in advance,

Brook

 

[domains]

Re: help with an 5 Pole Ignition Switch..

Most times its the gadge thats the prob fine points system .If needle is jumping cluster or no movement if so then its float. You know its one of the two stop testing our knowledge. you're walking on thin ice,be scared Very scared.

 

[MercFan]

Re: help with an 5 Pole Ignition Switch..

Damn, I'm not close to my engine atm, and won't be seeing it for a coupla weeks, but as far as I can remember I wired my electrical diaphragm pump to the purple wire of the harnass. I don't even see it on that diagram, and I have a '70 1150. But my control differs from the one shown as my choke button is part of the key switch.

But on a fuel gauge I'd remove the sender from the tank and the gauge from the dash. Build a circuit outside the boat and actuate the sender float. On the types that I'm familiar with the sender is a simple reostat (variable resistance), like the throttle control of a scalectrix. So the float depth in the fuel dictates the amount of resistance in the circuit. When the tank is empty the resistance is high and the needle doesn't move. When the tank is full the resistance is low and the needle moves to the full position. What happens sometimes is the feeler on the reostat wears through the resisance coil wires and you wind up with an open circuit and your gauge always shows empty.

Don't know if all that helps.

 

[Chris1956]

Re: help with an 5 Pole Ignition Switch..

Brook, The original 1977 MerControls on that motor had the three wire plug connector on the front of the control. White is the +12V accessory wire. Black is the ground and the Brown wire was the tach sender wire. The white wire had enought current carrying capacity to run the gauges and a small radio, like a boom box. if you need more current you need to run a seperate power and ground wire from the battery.