Installing water temp and voltage gauge questoin

[jasguild]

Hi

I am installing a water temp and voltage gauges. I would like to ensure that these gauges only receive power when the engine is running which is how I think the other gauges are wired. Any idea on the easiest way to accomplish this? I was thinking of sharing the power wire of the speedo or tach gauges.

Any ideas would be appreciated

 

[jasguild]

If I just tapped power off the power block under the dash, it would mean these gauges will be fed power even when the engine is off (as long as the battery switch is turned on). I am not sure if this is a good idea and it doesnt seem to be how the current gauges are wired.

Any help would be appreciiated

 

[Coastiejoe]

Almost any hot wire will be fed from the MPEM. For that reason, I would be looking for a ground.On ski's, I believe the DESS post ground is dead until the lanyard is on it.

I have no clue on Merc powered Boats.
[MENTION=16022]Dr Honda[/MENTION] will know for sure the best option.

 

[jasguild]

sad to admit but I have a mercury system and I don't know whether the lanyard cuts the whole system power. I always assumed it just cut the engine power and not the whole system power. as such I always leave the lanyard connected and use the battery switch to cut the power

 

[Dr Honda]

The lanyard on the Merc boats is just a ground for the CDI's. It shouldn't have any control over power. If it does... then a previous owner has been messing with it.

Tapping the power from the other gauges is perfectly fine.

 

[jasguild]

Thanks Dr. Honda

Out of curiosity do you know if the tach, speedo and fuel gauge get power when the engine is off but battery switch on? I am trying to figure out if they are drawing power from my battery when I am not running the engine.

Also do you know where I can find diagrams for these gauges? They have numerous wires. If not I will pull out my 12 V meter

 

[Dr Honda]

Ummmmmm.....................................................



Everything powers up when the switch is on... but the gauges should turn on/off with the key. (FYI: it's the purple wire off the key)

 

[xlonewolf1967]

my horn light stays on with the key off and battery switched to on... hmmm that's not right

 

[Dr Honda]

nope. The switch lights should come on with the Nav lights. BUT... Carling makes switches all different ways. Someone may have swapped that switch with the wrong style.