Tachometer Install
Thread Starter
|
Senior User
Joined: Jan 2014
Posts: 125
Likes: 0
Tachometer Install
I've searched through the treads looking for prior posts on this but have come up empty.
I have a tach from my prior life (yeah, I showing my age). It is an original tach from a 1964 Merc Comet Cyclone. It was a hot car in its day. 289 with 4spd. It has 3 wires coming out of it (black, red, and blue). I'm assuming the blue is for lighting, but that's a guess.
Does anyone know how the wires should be connected for an install on a 74 F100 360v8 auto? I've checked the other Ford forums w/o success. Not much on the 64 Comet.
Thank you
I have a tach from my prior life (yeah, I showing my age). It is an original tach from a 1964 Merc Comet Cyclone. It was a hot car in its day. 289 with 4spd. It has 3 wires coming out of it (black, red, and blue). I'm assuming the blue is for lighting, but that's a guess.
Does anyone know how the wires should be connected for an install on a 74 F100 360v8 auto? I've checked the other Ford forums w/o success. Not much on the 64 Comet.
Thank you
Senior User
Joined: Aug 2011
Posts: 118
Likes: 0
From: Florida
COMET PERFORMANCE • View topic - Tach wiring
Rotunda tach... - Ford Muscle Forums : Ford Muscle Cars Tech Forum
The FORDification.com Forums • View topic - Rotunda tach on pertronix
not sure if this is the style tach you have. good luck
Rotunda tach... - Ford Muscle Forums : Ford Muscle Cars Tech Forum
The FORDification.com Forums • View topic - Rotunda tach on pertronix
not sure if this is the style tach you have. good luck
Thread Starter
|
Senior User
Joined: Jan 2014
Posts: 125
Likes: 0
Thanks for your replies. I ran into those threads and the wiring appears to be as clear as mud. I have no idea if this tach is rotunda. It is a 6k tach, not 8k and only carries the label "cyclone" which was for the car model. It is from 1964. The comet cyclone was a negative ground system. I also went to the merc forums looking for some id of the unit. Zip.
If this is a rotunda and is wired to ground the unit and ignition system will be fried if the treads are correct. What else could the black wire be for? Logic seems to point to splice the red wire to the red ignition wire behind the ignition switch and then connect black to another black or directly to ground. Then the blue would be for illumination. But, not sure it is worth the risk of cooking things..... I plead minimal knowledge of this area and I hate to start hacking wires under the dash.
Keep your input coming if you think you can help. Thanks
If this is a rotunda and is wired to ground the unit and ignition system will be fried if the treads are correct. What else could the black wire be for? Logic seems to point to splice the red wire to the red ignition wire behind the ignition switch and then connect black to another black or directly to ground. Then the blue would be for illumination. But, not sure it is worth the risk of cooking things..... I plead minimal knowledge of this area and I hate to start hacking wires under the dash.
Keep your input coming if you think you can help. Thanks
Post Fiend
Joined: Apr 2008
Posts: 5,338
Likes: 3
From: Grants Pass, Oregon
One wire lights it, one wire provides it power (key on), and the third wire takes the impulse from the ignition to determine rpm, it will get ground from its mounting presumably.........With red to ignition switch, you would simply get power, constant 12V power, and black to ground, and blue to instrument lights, you would have no pulsed input to show rpm.....take a look at the tach, see if it has a C3RZ________ id number on the case somewhere, and then at least you would know that the instructions apply to this unit
Thread Starter
|
Senior User
Joined: Jan 2014
Posts: 125
Likes: 0
Thank you iggybob. The only thing on the inside of the case is "Patent #3005155. Thomas Faria Corp., New London, Conn., 8cyl". Odd, this was a factory installed item in 1964. I was in the car when it was driven off the showroom floor. This was also the start of the muscle car era and Ford, perhaps, went to an off company supplier for a quick accessory.
I appreciate your feedback. Maybe I'll do some research on Thomas Faria Corp.
I appreciate your feedback. Maybe I'll do some research on Thomas Faria Corp.
Thread Starter
|
Senior User
Joined: Jan 2014
Posts: 125
Likes: 0
Thomas Faria is apparently a privately owned instrument manufacturer back east. I have sent them an email. Hopefully this is promising. Guess the message is to keep picking off the onion layers....
Thread
Thread Starter
Forum
Replies
Last Post
