’69 Tachometer conversion
Thread Starter
Burning Brakes
Joined: Aug 2007
Posts: 1,173
Likes: 1
From: Liberty Missouri
’69 Tachometer conversion
I have done a search on tachometer conversions from mechanical to electrical, not much in the archives. I did see some information about sending my current tach off and having it converted. What I would prefer to do if possible is by a new electronic tach. I have heard that the tachometers in a 75-77 are electronic and are plug and play where my tach is. Is this true? Anyone done this?
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
I have done a search on tachometer conversions from mechanical to electrical, not much in the archives. I did see some information about sending my current tach off and having it converted. What I would prefer to do if possible is by a new electronic tach. I have heard that the tachometers in a 75-77 are electronic and are plug and play where my tach is. Is this true? Anyone done this?
Burning Brakes
Joined: Feb 2002
Posts: 752
Likes: 31
From: Melbourne Australia
Yes, I've used 77 tach in a 69. Fits like the original. Three wire hookup...1)ignition, 2)ground, 3) coil -ve terminal. It is a good idea to use a tach filter in the wire to the coil.
The letters and numbers on the face are a different style to the 69....perhaps you can swap the face plates?
Joe
The letters and numbers on the face are a different style to the 69....perhaps you can swap the face plates?
Joe
Thread Starter
Burning Brakes
Joined: Aug 2007
Posts: 1,173
Likes: 1
From: Liberty Missouri
Yes, I've used 77 tach in a 69. Fits like the original. Three wire hookup...1)ignition, 2)ground, 3) coil -ve terminal. It is a good idea to use a tach filter in the wire to the coil.
The letters and numbers on the face are a different style to the 69....perhaps you can swap the face plates?
Joe
The letters and numbers on the face are a different style to the 69....perhaps you can swap the face plates?
Joe
The main thing was,would it fit in the housing.
Burning Brakes
Joined: Feb 2002
Posts: 752
Likes: 31
From: Melbourne Australia
Hmmmmm....I'm sure you can swap the faceplates, just check the markings for rpm are the same....i.e, is 4000 in the same place on both faces?
It definitely fits fine and has all the holes in the right places for the instrument illumination and Brake / Indicator lamps.
I swapped in the speedo from a 77 as well, so i had the speedo and tach matching without swapping faceplates.
The tach filter is to stop the tach from bouncing around due to spikes from the coil, it may also protect the tach circuit from failure. Anyway they are cheap itms from the vendors, I'd put one in!
Joe
It definitely fits fine and has all the holes in the right places for the instrument illumination and Brake / Indicator lamps.
I swapped in the speedo from a 77 as well, so i had the speedo and tach matching without swapping faceplates.
The tach filter is to stop the tach from bouncing around due to spikes from the coil, it may also protect the tach circuit from failure. Anyway they are cheap itms from the vendors, I'd put one in!
Joe
Instructor
Joined: Oct 2006
Posts: 219
Likes: 0
From: Jupiter FL
I have done a search on tachometer conversions from mechanical to electrical, not much in the archives. I did see some information about sending my current tach off and having it converted. What I would prefer to do if possible is by a new electronic tach. I have heard that the tachometers in a 75-77 are electronic and are plug and play where my tach is. Is this true? Anyone done this?
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Burning Brakes
Joined: Feb 2002
Posts: 752
Likes: 31
From: Melbourne Australia
Yep,
The needle pulls off. You need to be very careful...it is often firmly on the shaft so take care not to break it, pull only on the "hub".
Carriljc....yes easy to build your own....do a search and you'll find the circuit diagram on this forum...
http://forums.corvetteforum.com/show...ht=tach+filter
One thing though!!!!
When you put the needle back on have the ignition on and ground connected and put the needle on at 0 rpm. Otherwise the rpm could be way off when you power it on because it is free to "rest" anywhere unlike the mechanical tach.
Joe
The needle pulls off. You need to be very careful...it is often firmly on the shaft so take care not to break it, pull only on the "hub".
Carriljc....yes easy to build your own....do a search and you'll find the circuit diagram on this forum...
http://forums.corvetteforum.com/show...ht=tach+filter
One thing though!!!!
When you put the needle back on have the ignition on and ground connected and put the needle on at 0 rpm. Otherwise the rpm could be way off when you power it on because it is free to "rest" anywhere unlike the mechanical tach.
Joe
Thread Starter
Burning Brakes
Joined: Aug 2007
Posts: 1,173
Likes: 1
From: Liberty Missouri
Yep,
The needle pulls off. You need to be very careful...it is often firmly on the shaft so take care not to break it, pull only on the "hub".
Carriljc....yes easy to build your own....do a search and you'll find the circuit diagram on this forum...
http://forums.corvetteforum.com/show...ht=tach+filter
One thing though!!!!
When you put the needle back on have the ignition on and ground connected and put the needle on at 0 rpm. Otherwise the rpm could be way off when you power it on because it is free to "rest" anywhere unlike the mechanical tach.
Joe
The needle pulls off. You need to be very careful...it is often firmly on the shaft so take care not to break it, pull only on the "hub".
Carriljc....yes easy to build your own....do a search and you'll find the circuit diagram on this forum...
http://forums.corvetteforum.com/show...ht=tach+filter
One thing though!!!!
When you put the needle back on have the ignition on and ground connected and put the needle on at 0 rpm. Otherwise the rpm could be way off when you power it on because it is free to "rest" anywhere unlike the mechanical tach.
Joe
