Tach cluster install how to

[Justins76]

If you have a non tach cluster and want to put in a tach cluster, follow along to see how its done to go from this

[Justins76]

to this:

[Justins76]

Some info to think about before installation:

There are many different combinations of clusters based on year and options. I chose a cluster with the fuel gauge built into the tach. In the lower left gauge hole, I used a vac gauge. These clusters also came with an air press gauge. You can also install a clock in there if you wish. I touched up the needles with Testors florescent red paint and used a 3M headlight refinishing kit to polish the lens. I removed everything from the cluster, cleaned it and then painted it flat white. Now is a good time to install new bulbs. You can choose from #192 (2 candlepower), #168 (3cp) or #2825 (4cp). While your at it, you can replace the a/c control light from #1445 (1cp) to #1893(2cp) to brighten things up at night.

Since there are so many different combinations of clusters based on year and options, it's up to the installer to correctly find out what wires in the harness need to be moved where for proper operation of the new cluster. You can follow the traces on the back of your original cluster and see where they lead to. Make a chart and write it down. Do the same for the new cluster. Then compare the two. You will then know exactly which wires need to be moved. The wires for the tach are a separate harness and they will not plug into the cluster harness. For these, tap into a switched 12v wire, ground and tach signal from the dist cap. The wires are marked on the rear of the tach. The pigtail for the tach output at the dist cap is Pico brand # 5664PT .

The BRAKE light operates buy supplying a ground to turn the bulb on. The BELTS light operates by supplying 12v power. Since my old cluster had both BRAKE and BELTS lights and the new cluster didn't, I had to make my own. I used some red transparencies that were matte on one side and made a photoshop file. I then printed it on a laser printer and cut it to shape and installed it on the cluster under the speedometer. I also had to make one hole for a bulb (cluster only had 1 but had room for 2). The transparencies are available at your favorite paper store.

If originally equipped with a voltmeter, you can use an ammeter cluster by moving the terminal at the 3 o'clock position to the 12 o'clock position. First remove plastic insulation over the copper trace, then clean off any left over adhesive. I then used 3600 grit sandpaper to make the copper nice and shiny. The terminal just snaps in. Then install original voltmeter. *note you cannot just install a voltmeter into a truck originally equipped with an ammeter. The vehicle wiring is different.

I also installed a gear shift indicator for my future 700r4 install. The part number for the OD indicator is #25078572

[Justins76]

Installation:

First, remove gauge bezel and then remove original cluster. It is held in with 1/4” hex heads. As you pull it out, reach behind and unclip cluster harness. And speedo cable. If you have a mech oil gauge, unscrew the metal line on the rear of the gauge. For reference, take a photo of your harness so you will know what color wires originally went where. More then likely, you will have to move the wires in the harness around to fit the particular cluster you are installing. You can use a small screwdriver inserted into the front of the plug to push the lock tab on the terminal in, then slide the terminal out from behind. This is why its good to have a picture for reference. Compare the clusters and make a chart like I suggested above. Move the wires in the harness to the correct position for the new cluster. Wire up tach harness. Reinstall cluster and verify all gauges operate properly. Then reinstall bezel and enjoy your new tach cluster.

[lo72]

This is a sweet write up! Good job....where did you get the gauge set up? with the tach/fuel gauge combination???

[Justins76]

Originally Posted by lo72

This is a sweet write up! Good job....where did you get the gauge set up? with the tach/fuel gauge combination???

I got it off ebay. They come up quite frequently.

[lo72]

Thanks Again

[Justins76]

Happy to help.

[nbpro]

good Tutorial

[bigtfan]

What year model did your gauges come out of with the tach and fuel together

[Justins76]

update- Bulb #1916 fits the a/c controls and its 3cp.

[BB77]

Hey i have the same setup in my 77. Everything worked but the fuel guage got any ideas?
Also i bought a 7k tach and fuel combo for my 85 dually. It was some kind of brand new reproduction on Ebay. It worked also with the exception of the fuel guage. I noticed some smoke coming from behind the tach while it was running so i killed it and unhooked the battery. You or anyone else have an idea what is going on with this? I have heard that different vehicles and different guages have different resistance/ ohms.

77 2wd 1/2 ton 454/400 12 bolt 3:07
85 4wd 1 ton single cab 454/400 dana 60 and hd 70

[Junqueboi]

Originally Posted by Justins76

Since my old cluster had both BRAKE and BELTS lights and the new cluster didn't, I had to make my own. I used some red transparencies that were matte on one side and made a photoshop file. I then printed it on a laser printer and cut it to shape and installed it on the cluster under the speedometer. I also had to make one hole for a bulb (cluster only had 1 but had room for 2). The transparencies are available at your favorite paper store.

Hi Justin,

Nice job on the mod. Can you go into more detail on your Brake/Belts lens? Any pics, additional information would be helpful. I've spent hours searching the net on how to do this & all I find is garbage.

Do these transparencies come in blue, green, or orange also? When you say paper store, are you talking like Kinko's Copies? What exactly should I ask for?

My S10 is going to be difficult to change because there's only one "strip" and somehow GM made it with red, green, blue, and orange in one solid piece. I removed the carb heat grid & ran power to the unused "check engine" light on my dash but I want it to read "Cold" instead.

[motornut]

it needs to have some wires moved
i did my 78 from idots to factory tach/gauge
may find some help below in my 78 jimmy thread

http://67-72chevytrucks.com/vboard/s...=421767&page=2
starts post 190
maybe going clear lense....with coloured bulb?