Red wire Amp gauge

[Larry E]

I am going to replace my Amp gauge with a Volt gauge. I am seeing that the starter/solenoid post is not used on the volt gauge. All I see on the Volt gauge hook up is a black ground wire and purple wire to the ignition post. What do I do with the red wire from starter solenoid that is on the amp gauge? Lower R/H gauge in picture.

Larry E

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[Silvertip]

Re: Red wire Amp gauge

I'll make this as simple as possible:

1) You don't use either of the wires from the AMP gauge on the VOLTMETER!
2) Disconnect the two wires from the AMP gauge and join them. Insulate them well. Leave everything as it was on the solenoid.
3) Install the voltmeter.
4) Connect the "I" terminal on the voltmeter to the "I" terminal on any other gauge.
5) Connect the ground terminal on the voltmeter to the ground terminal on any other gauge.
6) Connect the "L" (light) terminal on the voltmeter to the "L" terminal on any other gauge.
7) Go boating.

Voltmeters and ammeters are very different gauges and do not directly interchange. Ammeters measure current flow 'through" a circuit and hence are in series with the line. Voltmeters measure voltage "across" a circuit and therefore are placed across the line and ground circuits.

 

[NYBo]

Re: Red wire Amp gauge

I'll add just one thing to Silvertip's advice: If you can find a spot closer to the battery and solenoid to jumper the ammeter wiring, do it there. Even better, directly connect the terminals from one to the other with a continuous wire. You want those heavy wires to be as short as possible.

 

[Silvertip]

Re: Red wire Amp gauge

For the novice -- keep it simple. Do it at the gauge. The battery charged just fine for decades with the gauge in place. It will work just fine without it.

 

[Larry E]

Re: Red wire Amp gauge

OK great. Now just to be sure. You are saying to connect the orange and red wires on the amp meter together at the wire ends correct? This seems to complete a circuit from the alternator directly to the solenoid. Just want to be correct on this. Sorry if I seem slow on this but want it right the first time.

For the novice -- keep it simple. Do it at the gauge. The battery charged just fine for decades with the gauge in place. It will work just fine without it.

 

[Silvertip]

Re: Red wire Amp gauge

That is correct. Remember -- ammeters are in "series" with the line. Voltmeters are "across" the line and ground. The only reason to make the connection back at the engine would be to eliminate the run up front and then back again. As I said -- it worked with the meter in place and it will work without it. Since all of the current required to run accessories passes through those heavy wires, boat manufacturers began installing voltmeters so they didn't need those two heavy wires. Besides, most folks didn't understand what an ammeter was telling them anyway which is why auto makers went to idiot lights years ago. Gauges have made their way back again but those same folks still don't know what they mean so some sort of "information display" pops up to say "hey dude - check your gauges" or something similar.

 

[Larry E]

Re: Red wire Amp gauge

One more confirmation note. Looking at the picture of the back of my dash board you are talking about the large orange wire on the ignition switch and the large red wire on the amp gauge correct? Because the large orange wire goes to the alternator and the large red wire comes from the solenoid. If I do that where does the ignition switch get its positive feed from?

Thanks again Silvertip great information as usual and I appreciate your patience...
Larry E

That is correct. Remember -- ammeters are in "series" with the line. Voltmeters are "across" the line and ground. The only reason to make the connection back at the engine would be to eliminate the run up front and then back again. As I said -- it worked with the meter in place and it will work without it. Since all of the current required to run accessories passes through those heavy wires, boat manufacturers began installing voltmeters so they didn't need those two heavy wires. Besides, most folks didn't understand what an ammeter was telling them anyway which is why auto makers went to idiot lights years ago. Gauges have made their way back again but those same folks still don't know what they mean so some sort of "information display" pops up to say "hey dude - check your gauges" or something similar.

 

[Larry E]

Re: Red wire Amp gauge

I have the volt meter on and working and the only wire I have left over from the AMP gauge is the large orange wire from the alternator. Is that right?

Larry E

 

[Don S]

Re: Red wire Amp gauge

If you don't hook that wire up, and try to start the engine, it will probably blow the diodes out in your alternator. Without that wire hooked up, the charge wire from your alternator is not hooked up to the battery, just dead ended. Your alternator would keep building up voltage until the diodes go.

 

[Silvertip]

Re: Red wire Amp gauge

Man -- you need to follow directions. You removed the red and orange wires from the ammeter did you not? Then connect those two with a butt splice and cover with heat shrink. So if you have the orange wire left, what did you do with the red wire?

 

[Larry E]

Re: Red wire Amp gauge

OK sorry to be a pest but I am doing everything you say. The red wire is connected to the B post on the ignition switch. Nothing works without it being there.

Man -- you need to follow directions. You removed the red and orange wires from the ammeter did you not? Then connect those two with a butt splice and cover with heat shrink. So if you have the orange wire left, what did you do with the red wire?

 

[Larry E]

Re: Red wire Amp gauge

The red wire on the amp gauge turned out to be a jumper wire from the battery post on the ign sw.

 

[bruceb58]

Re: Red wire Amp gauge

If it were my boat, I would probably do a bit more re-wiring. On the typical ammeter setup, one large wire goes from the alternator to one side of the ammeter and also through a fuse to the ignition switch. The other wire goes back to the battery. The problem is that the alternator then has to deliver its current through this very long wire. I would take the wire that goes back to the battery and have it run through the fuse to the ignition switch. I would remove the wire that goes from the alternator up to the gauge and connect it from the alternator to the battery directly or to the common of a battery selector switch if you have one.

This is from another thread.

 

[Silvertip]

Re: Red wire Amp gauge

Since the orange wire is not connected, running the engine will 1) not charge the battery and 2) as Don said, probably hatch something in the chargine system.

Obviously the "B" terminal on the ignition switch needs power or nothing works. What you did is one way to do that. However, the red and orange wires still need to be connected so the charging system works. Since you have the system 1/2 correct, go back to the engine and locate the other end of the orange wire. Either pull the orange wire all the way out of the harness (if possible), shorten it, and then connect that shortened wire to where the RED wire is connected. That accomplishes the same thing as what you were told to do at the helm, but at the other end of the boat. If you can't get the orange wire out of the harness cut the wire at a point where the engiine end will reach wherever the red wire is connected. Add a ring terminal and connect it to the same spot the red wire is on. Then tag the orange wire at both ends as "not used" so the next owner or a shop knows what the deal is.

 

[Larry E]

Re: Red wire Amp gauge

Silvertip you have a silver tongue. That was exactly what I needed to hear...Thanks again for your patience.
Larry Ey

Since the orange wire is not connected, running the engine will 1) not charge the battery and 2) as Don said, probably hatch something in the chargine system.

Obviously the "B" terminal on the ignition switch needs power or nothing works. What you did is one way to do that. However, the red and orange wires still need to be connected so the charging system works. Since you have the system 1/2 correct, go back to the engine and locate the other end of the orange wire. Either pull the orange wire all the way out of the harness (if possible), shorten it, and then connect that shortened wire to where the RED wire is connected. That accomplishes the same thing as what you were told to do at the helm, but at the other end of the boat. If you can't get the orange wire out of the harness cut the wire at a point where the engiine end will reach wherever the red wire is connected. Add a ring terminal and connect it to the same spot the red wire is on. Then tag the orange wire at both ends as "not used" so the next owner or a shop knows what the deal is.