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Discussion Starter #1
What all is needed to make a Tach work in an '86?

I have an '86 that came from the factory with gauges & speedo. The lighting circuit went bad & I replaced the whole cluster with another G-Body cluster that I had. The new cluster has a tachometer that I'd also like to hook up.

What will it take?

Thank you
~JM~
 

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you will need the resister that goes to the tach terminal in the dist.it screws to the firewall between the dist and brake booster.a junkyard part as its not available from gm any more.any third gen camaro will work as long as it has a v8.then you will need to run the white tach wire to the cluster plug i believe pin 17. the hot and ground are already in the printed circuit
 

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Checked green circuit board?

JM, Have you the checked the green circuit board also? Last time I attempted this on my old '86, in addition to the wiring connections CCC has mentioned, that circuit board was always a problem for me. I changed the board with a used one, and it only worked on occasions. I abandoned a final fix & ignored it, since it came on when it wanted to,.. - George
 

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Discussion Starter #4
The circuit board looks good & seems to be functioning at least with the rest of the panel. It looks like the Tach is ready to go, it just needs the information signal.

Thank you
~JM~
 

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First, you need to get a tach filter. There are several available on E-bay. Search for a 87 monte carlo tach filter. This mounts on the fire wall and connects to the tach output on the HEI distributor. Look Under the dash on the drivers side by the radio and you should find a white wire with a brown single lug connector clipped to the forward edge of the dash. The tach filter will plug into this connector an the tach should work.
 

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Maybe that is what I need to make mine work right. It started to work again today after not working for about a year, but it reads about 4000 at idle and pegs out at cruising speed. What does a tach filter look like and would it work for an 84 with the comp and stuff removed?
 

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it looks like a capacitor with a wire comeing from each end of it and bolts to the firewall between the dist and the brake booster.it has a plug for the dist and a connector for the dash plug.without it the tach reads all crazy.you can get them from any 80s g body or camaro/firebird with a v8 and tach
 

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Following this thread. I have a 87 Caballero. The printed circuit has Gnd 12V and Coil as well as Bat. Pin 17 contains a white wire. I am assuming I need to find the connection under the dash and run the wire to the distributor. (I have the tach filter). What I really need to know is what am I looking for at the distributor to connect to?
 

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Discussion Starter #10
Thanks for all the replies. By any chance does anyone have an extra Tach Filter & Line that they'd like to sell? Please reply here or by PM.

Thank you
~JM~
 

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Fastest way would be to go to a Chebby dealer, BUT be prepared to pay thru the nose, and any other orface.
 

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Following this thread. I have a 87 Caballero. The printed circuit has Gnd 12V and Coil as well as Bat. Pin 17 contains a white wire. I am assuming I need to find the connection under the dash and run the wire to the distributor. (I have the tach filter). What I really need to know is what am I looking for at the distributor to connect to?
Distributor has a second terminal next to the ignition terminal for the tach. Mine was even marked tach.
 

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Discussion Starter #18
Well... I think I may have a new problem.

I think I have a Tach intended for a 6-cylinder vs. my V-8. My redline begins at 4500rpm & the Tach ends at 6K.

I don't suppose there is anything that can be done about this other than to find another Tach?

Thank you again
~JM~
 

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Well... I think I may have a new problem.

I think I have a Tach intended for a 6-cylinder vs. my V-8. My redline begins at 4500rpm & the Tach ends at 6K.

I don't suppose there is anything that can be done about this other than to find another Tach?

Thank you again
~JM~
Actually some of the V8 tachs did start with a lower redline. Other members have posted up indicating they've been one owners of crucks with that tach.
 

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Tach replacement=not working

I also installed a tach, pre 86, so not sure if its' from a V-6 or V-8, which I am told is critital to know. This tach has the small clock, so once hooked up to the posts it's working. The Tach stays at zero a idle, but moves & stays at 4,000. Does not register after that and may move slightly. When engine is off, may still rest at 4K. I did not have this talked about resister wire or filter, so may have discovered my problem. As you asked, where does this connect? Thanks, N
 
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