[edhjohnb]

Hi Guys, I need some help. I have a 67 RS with the factory console/gauges. Prior to installing a new console and gauges, my factory tach was working fine. Now that I've connected the gauges, I must have a ground problem somewhere because the tach barely registers at all (slight movement up to about 600 RPM).

Any thoughts on what I've done/need to do?

[67 RSS]

I just spent 3mos getting mine to run (two tachs and a flaky vendor- ok two vendors).

Anyway the signal wire and the power wire come in on the harness. The tach gets grounded thru one of the studs on back of tach/circuit board to the housing. The housing gets grounded by the heavy grounding wire or strap (two versions) that comes from the high beam light (to best of my knowledge).
So to test if it is your ground just reach up and ground the speedo tach housing to ground (sill plate screw is handy or e-brake bracket) and see if tach movement better.
I sanded the clip that the ground wire and screw goes into at the dash- it gets covered by the bezel. I also lightly sanded (1000 grit) the Cu circuit board connections where the wire harness plug goes in to ensure a good connection for the other inputs- was surprised how oxidated the Cu strips were.
Farmboy has a great post on calibration if you do a search which you might find helpful as well- thanks for that Steve.

[edhjohnb]

Thanks Lane. I'll try that with that tach.

As far as the console gauges go, are they grounded anywhere besides the black ground wire from the harness?

[camaron de la isla]

hi guys,

i have a problem with my tic toc tach on my 68.

i replaced the old dash fuel gauge with the tic toc tach. i installed the console gauges with original extension harness, i changed also the dash circuit board. so far so good...

i received all the wiring diagrams to make this changes, but i dont know how to connect the clock in the middle of the tach. i have 3 connections behind the tach, one wire is red, ons wire is orange and one is blue.

i guess the blue one is connected to the coil, but what about the rest?
wich one is for grounding and wich one is the power for the clock?

please help me out

thx Turi

[melsman]

Hi Turi,

There are three posts on the back of the tach - one at 12 o'clock, one at 4 o'clock, and one post at 8 o'clock. The post at 4 o'clock is the clock power(+). The post at 12 o'clock is for the tach signal (to coil).

Hope this helps.

[JimM]

blue = tach signal from coil.

orange = bat pwr for clock

red = ign power for tach
could be backwards on those... if you look at the orange and red wires, you can see which goes into the clock, that one needs bat pwr
ground is thru the case

[cmcamaro69]

Factory tach install instructions on my blog http://1969camarothumpr.blogspot.com/