tach wire
Thread Starter
Navigator
Joined: Mar 2007
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tach wire
81 Vette mostly original. My tach wire that comes out from the dist. is not plugged in. I cant find a matching plug under the hood anywhere. It appears to be a yellow or white wire (cant tell) Can somebody tell me where this thing is supposed to plug into?
Great site!
Thanks for the help.
Brian
Great site!
Thanks for the help.
Brian
Le Mans Master
Joined: Mar 2001
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From: Ann Arbor Michigan
On my 78', there is a white wire that comes from the "Tach" connection on the dist cap and goes through the firewall and connects to the tach somewhere under the dash. I would think an 81' is the same.
Le Mans Master
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From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
SOme cars had a Tach filter- looks like a condenser, mounted somewhere around the disty. Could be on the engine or the firewall, but would, in either case, be within reach of your Tach wire coming from the disty..
Le Mans Master
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From: Omaha NE
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On mine the dist tach wire is soldered right to the filter mounted on the intake. The wire off the filter then has a connector to another that goes on thru the firewall. Mine's original too......
Thread Starter
Navigator
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yes this wire does have the filter attatched but it isnt mounted to anything. No my tach doesnt work right now.
So this wire should go into the firewall and plug into the tach?
Actually there are 2 wires coming out of the dist on the tach side. both have the same female connection and arent pluged into anything. One has the filter and is 15 inches long. THe other has no filter and is only 3 inches long???
THanks
BH
So this wire should go into the firewall and plug into the tach?
Actually there are 2 wires coming out of the dist on the tach side. both have the same female connection and arent pluged into anything. One has the filter and is 15 inches long. THe other has no filter and is only 3 inches long???
THanks
BH
Le Mans Master
Joined: Dec 2006
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yes this wire does have the filter attatched but it isnt mounted to anything. No my tach doesnt work right now.
So this wire should go into the firewall and plug into the tach?
Actually there are 2 wires coming out of the dist on the tach side. both have the same female connection and arent pluged into anything. One has the filter and is 15 inches long. THe other has no filter and is only 3 inches long???
THanks
BH
So this wire should go into the firewall and plug into the tach?
Actually there are 2 wires coming out of the dist on the tach side. both have the same female connection and arent pluged into anything. One has the filter and is 15 inches long. THe other has no filter and is only 3 inches long???
THanks
BH
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Le Mans Master
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Instructor
Joined: Oct 2006
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From: Jupiter FL
Quite often those tach filters went bad. That's possibly why yours was disconnected. Bypassing the filter frequently solved th problem
Le Mans Master
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From: Myrtle Beach SC
Le Mans Master
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From: Myrtle Beach SC
Tach on my 78 is not working so following the thread here. Schematic shows the white from distributor going through a couple of connector blocks and onto the printed board of the tach.
Pink wire connects to the tach directly and than the white lead connects to a brown lead which routes through the filter and onto the white wire. Leads coming out of the filter are brown. I'll try dropping the filter out of the circuit as described above.
Pink wire connects to the tach directly and than the white lead connects to a brown lead which routes through the filter and onto the white wire. Leads coming out of the filter are brown. I'll try dropping the filter out of the circuit as described above.
Thread Starter
Navigator
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Still no dice. I guess I need to replace the circuit board. When I plug the wires into each other the Tach pegs out. If I unplug it the tach eventually just wanders around with no change when the RPM's change. might go up, might go down, might peg out.
Thanks for the help
BH
Thanks for the help
BH
Le Mans Master
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From: Myrtle Beach SC
Instructor
Joined: Oct 2006
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From: Jupiter FL
Sounds like it may be the tach board. If you get the tach out, (the whole cluster does not need to come out) Just use care not to scratch up the housing because it's a pain to fix the scratches. On the back of the board are 6 screws. The top 3 are labeled. Connect 12 volts to the screw marked 12v, and ground to the one marked g. The pointer should go to zero. If it doesn't, that's a good indication the board is bad. It'll also give you a chance to inspect the board visually for any indications of burnt ares.
These are also liquid filled with a damping oil. Oftentimes the oil dries out and they act erratically, and need to be re-damped.
These are also liquid filled with a damping oil. Oftentimes the oil dries out and they act erratically, and need to be re-damped.
Last edited by gldnkngt; May 9, 2007 at 08:27 PM.
Le Mans Master
Joined: Sep 2002
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From: Myrtle Beach SC
In regards to the meter pointer, if it goes to zero, than the circuit is broken and therefore circuit board bad?
Melting Slicks
Joined: Sep 2004
Posts: 3,223
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From: Northeast
A link for the circuit board replacement. gldnkngt referred to the 6 screws on the back.
http://www.corvettemagazine.com/2005...ch/tach-01.asp
http://www.corvettemagazine.com/2005...ch/tach-01.asp
Drifting
Joined: Nov 2003
Posts: 1,634
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From: Northern NJ
St. Jude Donor '04 & '05
When these boards do fail, it is often one of a couple components and many times can be repaired. I've fixed several of them. If I can offer any assistance, please pm me.
Good Luck!
Good Luck!