90hp johnson wiring
 

Anyone know what color coming from the ignition is the hot wire for accesories, I need it for the fuel guage.

Quckest way to find out is to test it real quick.

If you have a test light, ground the clip, and test them all, the one that turns on and off with the key is the one. If your only going to run the fuel gauge, then you can directly hook it up, but if you plan on using it for more accesories then I suggest you setup a relay powered fuse box. This is very easy to do and can be done quickly.

Actually the tach must be hooked up also right?

To find the ignition switched power source? No, but if it is not hooked up, you should definelty hookit up, The tach lead on most OMC motors is the green wire. the other wires on the tach are the lights for at night, just like the fuel gauge. Why don't you pm me your phone number and we can talk about it.

Thanks Scott check your pm's