Mercruiser 1995 5.0

[Jeff D]

Just installed a new Tacho and I hooked up to the original signal wire but I can't calibrate it properly. It came with a new sender can anyone please tell me where the old sender is or is it just a wire off the distributor. Any advice would be appreciated.

Regards
Jeff

 

[AllDodge]

The Tach doesn't use a sender, it uses a gray wire which comes from the negative side of the coil

Post pic of the sender and tach

 

[Jeff D]

Yes that's the wire I hooked onto and the tacho is working but it's very spasmodic. I'll post a photo of both soon. Appreciate your help

 

[Droid]

A misfire will cause the tach to jump around. There should be a switch on the back to adjust for # of cylinders. Incorrect switch position will cause tach to read fast or slow but not spasmodic.
Check cap, rotor, wires & plugs.

Why did you replace the original?

 

[Jeff D]

Hi Droid

The old tacho was working fine so I know it's not the wires and rotor cap are not the issue. Yes got it on the correct 8 cylinder switch. I replaced the old tacho because I just wanted to update all the gauges

 

[Jeff D]

 

[Jeff D]

Please see attached photos

 

[Droid]

Like Alldodge said in post #2, the tach takes its signal from the gray wire.
I have no idea what you bought, maybe some Chinesium from Amazon?

 

[AllDodge]

Please see attached photos

Unable to see pics

 

[Jeff D]

 

[AllDodge]

Have a link to the gauge set you purchased?
Unable to understand what they have been designed for

 

[faztbullet]

Got a fast 5.0 in boat with a 125mph speedo. This is automotive not marine gauges.

 

[Jeff D]

Ha. Very fast boat . Speedo is fine and they are marine