Instruments in dash board

[aburke120]

I bought a 1990 Sea Nymph SS195 Fish and Ski that needs to be rewired. Under the dash is a rats nest, there's one buss bar for neutral, none for positive. splices, tape, loose wires, just a mess. I worked as an electrician in an iron foundry so things like this don't bother me. My question is, how much information do I need on the dash board. Right now there's a key switch with about 10 or more wires, gas gauge for inboard tank, speedo, tach, tilt and trim, switches for lights, live wells, bilge pump, I can't remember all of them, The merc control also has a key switch. thanks

 

[dingbat]

I personally feel trim gauges and speedos are useless, but then what do you do with the dead gages?

The non-functional gage would drive me crazy,

 

[gm280]

A single negative buss bar is typical. But any time you have a lot of taps off on any other terminal, an additional smaller buss bar works perfectly. Just make sure it is isolated to any possibility of shorting anything else out. And I like to use wire labels on ever wire. Because as more items gets installed, there will be way more wires. As for any gauges that are not functioning, You have a couple options. Either replace them with like kinds, if possible, or try and disassemble the gauge itself to see what is wrong with it. I mean since it is not working, you can't break it... And I concur with dingbat, speedometer and trim gauges are merely place holders and for looks. The basically give you no useful info... Usually a boat speedometer is nothing but a fancy water pressure gauge that never is remotely correct. JMHO

 

[aburke120]

what about the ignition switch on the dash, can it be eliminated? Switch has about a dozen wires, all with white lugs on them going to everything under the dash. The print I have for the merc control shows a positive and negative wire coming out the front of the controller labled tach connector. black, red, white wires. there's no plug in it.

 

[Scott Danforth]

for me, the most important gauges are as follows (in descending order of importance):

GPS chart map (because being as much as 2 feet off a channel means your calling a tow)
depth gauge (see above)
fuel tank level gauge (follow the rule of thirds, 1/3 fuel to get you to your destination, 1/3 to get home, 1/3 for reserve)
water temp gauge ( this is a good reading on the health of a motor)
water pressure gauge (I can tell if I picked up a shell or debris in the cooling system long before an overheat)
oil pressure gauge (oil is the blood of the engine)
oil temp gauge
engine RPM
Speedometer (many 25mph zones)
trim gauge
volt meter
fuel flow meter
VHF radio
tunes radio

regarding the dash wiring, it should be standard. look in the stickies on the electrical forum in over 31 years with multiple owners, guarantee people were in there.

for switches the must have for most boats:
ignition switch
dash light switch
nav/anchor light switch
horn switch

then depending on the boat, you go from there.

 

[aburke120]

still not finding any infomation about the key switch on the dash, and the key switch on the merc control. Do I need both of them? I'd like to clean up the mess under the dash, and that includes the key switch. I only have one print, and that's for the motor, and merc control. There are wires going to a plug on the front of the controller, the print calls this the tach connector, not sure if its just for the tach, or what. Wires .re black, brown and white. Looks like I'll be running a red and black from the battery to the dash board, then go from there. Thx.

 

[GSPLures]

I feel your pain my dash was rewired at some point with all yellow wire in a jumbled mess. My plan was to rewire according to the schematic to bring it back to stock then go from there with my upgrades.

 

[Scott Danforth]

still not finding any infomation about the key switch on the dash, and the key switch on the merc control. Do I need both of them? I'd like to clean up the mess under the dash, and that includes the key switch. I only have one print, and that's for the motor, and merc control. There are wires going to a plug on the front of the controller, the print calls this the tach connector, not sure if its just for the tach, or what. Wires .re black, brown and white. Looks like I'll be running a red and black from the battery to the dash board, then go from there. Thx.

you are going to have to post pictures....... something isnt right. you should only have one key switch.

is this an outboard or an I/O? if its an I/O, someone installed an outboard side controls. this could have also been an OMC equipped boat with a motor swap.