bought new volt meter and temp gauage

[efornoff]

bought new volt andtemp gauage, the wiring directions are the same for each gauage. don't I need temp sensor or is there one already one on the motor. 1984 merc 150

 

[Silvertip]

Re: bought new volt meter and temp gauage

The voltmeter only needs to be connected to ground and a 12V source that is hot when the key is on. A speparate terminal is provided for the light. It can connect to the same 12V line that is hot when the key is on or from a separate light switch. The temp gauge has four terminals. Ground, +12v (again hot when the key is on), 12v for the light (from separate switch or tap into the other 12v line so the light is on when the key is on) and the fourth connection is indeed for a temp sender. That sender may or may not come with the gauge. The sender must match the gauge.

 

[newuserguy]

Re: bought new volt meter and temp gauage

I'd be real careful of wiring anything into the key switch, any mistakes can cause real expensive problems. ALWAYS use a seperate connection to the battery and an inline fuse.

 

[Silvertip]

Re: bought new volt meter and temp gauage

So things like gauges can remain on all the time? Wiring gauges directly to the battery is a good way to run the battery down, even if they are run through a separate switch as there is a fair chance it will be left on accidentally more than you think. There is an accessory position on the ignition switch. It's specific purpose is to power the dash and any other circuits that need to be active when the key is on. .

 

[newuserguy]

Re: bought new volt meter and temp gauage

So things like gauges can remain on all the time? Wiring gauges directly to the battery is a good way to run the battery down, even if they are run through a separate switch as there is a fair chance it will be left on accidentally more than you think. There is an accessory position on the ignition switch. It's specific purpose is to power the dash and any other circuits that need to be active when the key is on. .

 

[newuserguy]

Re: bought new volt meter and temp gauage

I'd rather have a dead battery than an electrical surge or energized circuit burning up my switch box, stator, trigger, rectifier, power packs etc. All, or any of these can occur if the accessory items are wired incorrectly or short out. I figure better safe than sorry. ESPECIALLY, with the critical electrical components in today's engines. ALWAYS wire seperately to the battery with a buss and fuse. Heck, if you forget to turn the switch off and the engine is off the guages are not going to be a large drain anyway. I don't profess to be an elec. engr., BUT, I do know that good, sound marine practice is to NEVER wire into the switch on the control box.

 

[jddenham]

Re: bought new volt meter and temp gauage

Why not wire to the accessory component of the control box with an inline fuse?

 

[Silvertip]

Re: bought new volt meter and temp gauage

Anything the poster already has wired in the dash is very likely already wired through the accessory position on the ignition switch. There is no need to even get near the switch. If this is a side mount control the +12V and ground wires are already routed out of the control for use under the dash. One can also tap into the +12V, ground and light terminals on any of the existing gauges. The temp wire is already in the harness. This is not a difficult install.

 

[rickdb1boat]

Re: bought new volt meter and temp gauage

Yep. I'd just tag into the Tach. hot lead and be done with it....

 

[efornoff]

Re: bought new volt meter and temp gauage

hanks Silvertip, I need to know how to install the temp sending sensor. I have a fiting on top of the block on the left side where my water pressure hooks in ,can I hook into that.

 

[Silvertip]

Re: bought new volt meter and temp gauage

No! If you have a water pressure gauge it can be "Tee'd" into that fitting. How the temp sender is installed depends on what type of sender you have. If it threads into a hole, it needs to go into the water cover similar to this picture.

If its a thermocouple style, it goes under one of the water cover bolts. A third style requires that some paint be scraped from the water cover and sender is held in contact with the cover by a bracket bolted under one of the bolts.