OMC v-4 temp gauge

[2fast4u2]

Starting doding my wiring on the boat today. Stopped tonite to try and figure out how to wire my temp gauge.

Here is what i have so far.....

This is for a 88 johnson 110...

Under the cowl I can see that the engine has two temp senders, one in each head. They then are tied together to give one sender output, but that output has been cut off and there is only about 3 feet of total sender wire there. My question is what do I need to hook this thing up. I know I need ground, thats obvious, but do I just take power from a switch that comes from the battery. I dont have my control box that has the wiring harness and the red plug yet. or? Can I just patch in wire to the sender wire that was cut or are they a resistance wire that needs to be ran the whole way? Help!!!!

Thanks

Ryan

[t2stroke]

The wires that come out of the heads is for the warning horn in the control box. You need to spend your time making sure your warning system works well.

For a temp gauge you will need the mechanical sender unit that bolts on the head. There are a couple of problems with this method. First the temp switch will not react quick enough to save the engine even if you happen to be looking at it when the temps go up. Second the units are not very reliable. You need heat sink compund to insulate them so they conduct at all. They are really just a do-dad that puts another gauge on the dash for you to look at. My opinion for what it's worth..

[Rickracer]

...you're gonna need to tap a hole for a sender that will touch water. The ones you describe are, as t2stroke says, OEM senders for the warning horn system. A water pressure gauge would be a better way of safegaurding against an overheat, but it wouldn't hurt to have all 3, OE alarm system, water pressure, and temp gauge. In my experience, without maintenance, the OE system is good for letting you know you have just hurt your motor. You need to pull the senders , clean out the holes and senders , and re-install them with some heat sink compound, again, as t2stroke mentioned, so that they will respond as quickly as possible. A head mounted gauge will work, but don't work that well unless you are religeous about keeping them clean and in good contact with the head.

[2fast4u2]

Okay, thanks you guys.