Guages on 68 Penn Yan questions.

AKPilotnboatman

Seaman Apprentice
Joined
May 5, 2014
Messages
32
Hey guys. Finally making progress on the old 68 Penn Yan. Motor runs, it shifts, stays cool, steers. Very exciting. I am planning on doing a freshwater test run this weekend and am getting the instruments and gauges back in. I was playing with them the other night but was wondering about a couple.

What wires connect to temp, oil pressure, fuel gauge, and amp meter? I believe I have the oil pressure right with ignition, ground and oil sender. Temp is being tricky, but i think it is requiring ground, power (ignition or accessory?), and the sender unit. The dumb thing is that I had all this hooked up the other day when I was playing with it and i was able to get the desired results, I just forgot to write them down. I have the original wiring diagram but it is really difficult to follow due to the age. Any help would be great. Thanks!

Engine is a Merc 160

FISH ON
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
The "I" terminal on each gauge is simply jumpered from one gauge to the next with the source being the "RUN" position on the ignition switch. Ground is ground wherever you find it. The "S" terminal on each gauge goes to the corresponding sender (Oil, Temp and Fuel). Each gauge has an internal light. The "L" terminal again is jumpered from one gauge to the next with the source being the NAV position of the NAV/ANC switch. Unless you are trying to put this gauge cluster back to 100% original, I would replace the AMP meter (if that's what you really have) with a Voltmeter. Wiring is much simpler (same +12 volts in RUN position, ground and light. No sender with a voltmeter. Ammeters have way too much wiring and you will need to use the diagram you have for that one.
 

AKPilotnboatman

Seaman Apprentice
Joined
May 5, 2014
Messages
32
Well none of my gauges are labeled really, but i guess anything chained or jumpered is just a positive 12 v source?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
That would be a very wrong assumption. The internal light, +12 volt and ground lines may all be jumpered (daisy chained). Only the first gauge in the string needs to be connected to the +12 volt, light (NAV switch) and ground. I find it hard to believe there are no markings on the gauges. You should see a "+" or "I" for the +12 volt ignition switch source. The light will have an "L" and ground will be a "G" or ground symbol. Sender terminals will have an "S" marking. Even if there are no markings, look at the internal light bulb holder to determine where the connection is. The metal shell of the gauge is usually ground. +12 volts and the sender terminal will be a terminal that has an insulating washer under the nut that secures the wire.
 

AKPilotnboatman

Seaman Apprentice
Joined
May 5, 2014
Messages
32
Ok. I got it pretty good. I will eventually replace the ammeter with a volt, and all but one of my gauges are lightless (i guess in 1968 they just used flashlights or something) . anyway, should be good.
 
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