Installing Tachometer (updated)

[87GrandPrix]

Ok In this video of this 1988 Caprice with a 305 v8. http://www.youtube.com/watch?v=mntS-hXz-dQ he shows you how to install and what not, but his negative plug has 1 prong, mine has 2, now do I merge my green wire in with the wire that would normally run into his missing prong? how would I go about running my green tach wire into the left prong on my plug, I dont think there is room to stuff that tach wire into that hole like he did because I have a prong there and he doesn't.

Also what is a decent tachometer that you can mount under the dash for under $100?

 

[custom442]

The tach has 4 wires. 3 are needed to work properly. The green one connects directly to your distributor tach wire (might be white if it's stock) - you can either splice the green wire into the old one or replace the old one with the new green wire. Then you hook up the hot wire - splice or run/replace the new wire to any wire with juice when ignition is 'on' (when the key is turned on, but not engaging the starter) - either the choke wire or your distributor hot wire. Then the black one just grounds at any good ground.

The 4th wire, white, one you splice into your light wire for gauges. Or if you want, run it to a hot wire engaged on ignition and put a switch on your dash or somewhere for the backlight--remember to put a fuse in the circuit if you run it from a separate hot wire

Sunpro still sells their super tach II which is the cheapest one that I'm aware of. It works just fine, I have one for temporary purposes on my dash, and it can be installed under the dash, but it'd be hard to look at the road and your rpm's at the same time that way.

 

[dogsht]

How would like to have an Olds Ralley guage pak? Tach, oil pressure, coolant temp, plus the round analog speedo & fuel guage. $75. Its a drop in with instructions for putting it in your car online.

 

[dan2286]

How would like to have an Olds Ralley guage pak? Tach, oil pressure, coolant temp, plus the round analog speedo & fuel guage. $75. Its a drop in with instructions for putting it in your car online.

A drop in for a Grand Prix??

 

[87GrandPrix]

The tach has 4 wires. 3 are needed to work properly. The green one connects directly to your distributor tach wire (might be white if it's stock) - you can either splice the green wire into the old one or replace the old one with the new green wire. Then you hook up the hot wire - splice or run/replace the new wire to any wire with juice when ignition is 'on' (when the key is turned on, but not engaging the starter) - either the choke wire or your distributor hot wire. Then the black one just grounds at any good ground.

The 4th wire, white, one you splice into your light wire for gauges. Or if you want, run it to a hot wire engaged on ignition and put a switch on your dash or somewhere for the backlight--remember to put a fuse in the circuit if you run it from a separate hot wire

Sunpro still sells their super tach II which is the cheapest one that I'm aware of. It works just fine, I have one for temporary purposes on my dash, and it can be installed under the dash, but it'd be hard to look at the road and your rpm's at the same time that way.

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Thanks for the information, What is that wire that im splicing into, what does it do for me? and how can I replace it with the green wire?

 

[dogsht]

Sorry brain fart.

 

[custom442]

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Thanks for the information, What is that wire that im splicing into, what does it do for me? and how can I replace it with the green wire?

Your distributor (or coil) has two wires going to it. One should be white and the other red/pink.

The white one should be replaced with your new green tach wire. Or you could try splicing your green tach wire into the white one with a 3-way splicer.

The red is the distributor hot wire.

 

[87GrandPrix]

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Thanks for the information, What is that wire that im splicing into, what does it do for me? and how can I replace it with the green wire?

Your distributor (or coil) has two wires going to it. One should be white and the other red/pink.

The white one should be replaced with your new green tach wire. Or you could try splicing your green tach wire into the white one with a 3-way splicer.

The red is the distributor hot wire.

Where does the White one go to from the coil? Is it some sort of dead end wire used for the cars that did have the tach option? I have the clock.

 

[custom442]

Where does the White one go to from the coil? Is it some sort of dead end wire used for the cars that did have the tach option? I have the clock.

I'm not sure where it goes to tell you the truth. I would guess if your car wasn't equipped with a tach it goes to the computer to control some functions at certain rpms, maybe at idle, etc That's why I think you should splice into it with the new green wire, instead of replacing the white with green, unless you've removed all the electric/vacuum/original controls from your engine.

 

[87GrandPrix]

Where does the White one go to from the coil? Is it some sort of dead end wire used for the cars that did have the tach option? I have the clock.

I'm not sure where it goes to tell you the truth. I would guess if your car wasn't equipped with a tach it goes to the computer to control some functions at certain rpms, maybe at idle, etc That's why I think you should splice into it with the new green wire, instead of replacing the white with green, unless you've removed all the electric/vacuum/original controls from your engine.

Ok, Thanks, How would you go about splicing it. Ive done it but never on something like this. Where should I peel back the plastic and should I wrap the whole green wire around it and tape it or should I do a different approach.