Connect a shop tachometer to a 1998 Mercuiser 5.0L

[Maraian]

How to Connect a shop tachometer to a 1998 Mercuiser 5.0L bravo 2 bbl Distributor Thunderbolt V ignition?

 

[Bt Doctur]

tach + lead to a 12v source, tach negative lead to the neg side of the coil

 

[Maraian]

thanks, so my multifunction tach has 2 large clips ( 1red, 1 black) that assume go to the battery, then there is a small red, yellow and black clips.
So your saying just attach the small black clip to the negative side of the coil.
What do you mean by "tach + lead"

 

[Bt Doctur]

You never said exactly what brand tach you wanted to use so I generally gave the hook up for a dash mounted tach.
The red and black power clips are most likely correct the others I cant say. what do the instructions say about hooking it up

 

[Maraian]

The brand is RAC, I dont have the directions. But fiqured that they are pretty standard, I just have never used one before, also I have read that there may be a service wire that you can clip into? But I cant seem to get it to work?

 

[Maraian]

Someone must know how to hook up A shop tach to a 98 5.0? Anyone?

 

[achris]

If it has only 2 leads, black to ground, red to coil -....

 

[Maraian]

Red to the positive terminal of coil?

 

[achris]

Red to the positive terminal of coil?

No, I wrote coil -... Coil negative, the one with grey wires on it.

 

[Maraian]

So black goes to any ground and red goes to the coils negative terminal?

 

[NHGuy]

Check out this link, http://www.jalopyjournal.com/forum/threads/old-tach-identity.132103/maybe you can make some inference from this guy's use of an RAC tach from H.A.M.B. (the Hokey *** Message Board) where a lot of old car guys hang out.

 

[achris]

So black goes to any ground and red goes to the coils negative terminal?

:thumb:

 

[Maraian]

Thnx, it didn't work. I think the meter may be busted.

 

[Fun Times]

Thnx, it didn't work. I think the meter may be busted.

Have a photo of the back side of the tachometer gauge?

Also look around the top of your engine because "some" engine models offered a loose gray wire so you'd be able to connect an external shop tachometer such as the gray wire hopefully seen below with the black plug in it.