Tach Question

[fimpel]

I have a '76 1150 Mercury.
I have a tach hooked up but its an older tach. The boat I bought had all quicksilver gauges but when I had my motor put on the boat the guy took my older tach and used it. I want to use my quicksilver gauge.

It has 3 wires coming out of the control for the gauges. White, Brown, Black.
White = Positive
Brown = Tach sender
Black = Ground
Is this correct?

Also on the back of my quicksilver tach it has range selector.
1 = 4cyl
2 = 6cyl
3 = 8cyl
4 = 12 pole alter
what setting should this be on for my motor?

Also when hooking up the gauges I can run the positive wire from gauge to gauge to insure all gauges come on after key is turned on?

 

[Barnacle_Bill]

Re: Tach Question

Your wiring is correct.
Set it on #4 for 12 pole alternator
Yes, you can wire the pos that way.

 

[fimpel]

Re: Tach Question

Thank you for your help.

 

[Beefer]

Re: Tach Question

Don't mean to hijack the post, but do you wire the pos to your fuse block?

 

[fimpel]

Re: Tach Question

Thanks for the hijack.
I was just thinking the same thing.
I guess for safety reasons you would wire the positive into a fuse?
If so what amp would you use for 3-4 gauges?

 

[Barnacle_Bill]

Re: Tach Question

Positive gets connected to the purple wire connected to the ignition switch. This way the gauges work when the key is on.

 

[fimpel]

Re: Tach Question

I have a '76 1150 Mercury.
I have a tach hooked up but its an older tach. The boat I bought had all quicksilver gauges but when I had my motor put on the boat the guy took my older tach and used it. I want to use my quicksilver gauge.

It has 3 wires coming out of the control for the gauges. White, Brown, Black.
White = Positive
Brown = Tach sender
Black = Ground
Is this correct?

Also on the back of my quicksilver tach it has range selector.
1 = 4cyl
2 = 6cyl
3 = 8cyl
4 = 12 pole alter
what setting should this be on for my motor?

I hooked up the tach using the color code above. It doesn't work.

The other tach that works is hooked up like this.
White = tied into tach light then to positive.
Black = goes to positive on back of tach.
Brown = goes to negative.

The tach that works has only two connections on the back, positive and negative.

The tach I want to hook up has positive, negative, and sender connections.

So how would I hook the new tach up?

 

[fimpel]

Re: Tach Question

Anyone have an ideal on way my old tach works the way its hooked up?

 

[Silvertip]

Re: Tach Question

Old style tachs were a different design than the newer styles. They did not require a +12V connection. The POS connection was the connection to the stator just like the current tachs. Ground and light connections are also the same as the current designs.

 

[Moody Blue]

Re: Tach Question

I think this is what you need to do.

The older tachs worked differently than the newer ones. The tach signal for your older gauge is probably taken from the BROWN terminal/wire on the starboard side of the switchbox in the motor. This brown wire runs right thru to the control box then out thru the tach connection terminals on the front of the control box.

Your newer tach (quicksilver) needs a signal from a different source. You need to remove the BROWN wire from the starboard side of the switchbox (not the distibutor side) and connect it to either of the yellow wires on the rectifier. Other connections are WHITE-POS, BLACK-GND.