Tach help.

i tried to wire up the Dixco tac in my truck, came back with a problem.
now there are only 3 wires, 2 thick, 1 thin, for the thick ones there is a white and a black (power & ground) then the thin is a green (light).
now i guessed white was power so i hooked it up the the HEI's tac prong. then ground the black, turned it on and nothing. it didnt even move. switched the wires and it was pegged on 8 grand.
so does this mean my tac is bad or since its so old just not compatable with the HEI?
thanks guys.

 

i don't think you have enough wires...did you open it up and see if the green wire goes to a light? with white/black being power and ground you don't have a wire for the signal..is there a broke off wire inside?

i wouldn't hook ANY power wire the the TACH terminal on the HEI

 

so the white is power, the black ground and the green signal.
seems easy enough.
much apreciated.

 

Ok so that didnt work.

hooked the white to power, grounded the black & hooked the green up to the distrib. now it twitched when the key came on then when i started the truck it went right to peg at 8 grand.
i took it apart and i see nothing wrong, no extra wires, no missing wires, nothing wrong but just the fact it will not work.
any ideas?

 

Houses use white and black for power, but cars usually don't

Can you take a picture of the insides, especially where the wires connect?

 

My old s/w stage 1 tach only had three wires too, two went to the coil and one for ground. The light comes on right away when you turn the ignition on but the tach would not function wired differently.

 

i sure will get some pictures today for you.
its pretty simple inside, just a lot of resistors.

lBB41, i have HEI, if two of the wires are supposed to go to the coil, should i just run them together and plug them into the TACH port on the HEI top?

if it helps its a 'Dixco' tach part of the 'Dixson' parts devision.

 

The green wire always goes to the (-) side of coil...or the TACH term. on HEI. If your Tach pegged the needle at startup, check the inside for a switch to select from 4-6-8 cyl......it sounds like its set for the wrong # of cyl.
Generally tachs have 4 wires. Green=tach, black=ground, red=power(ign), white=internal light.

 

it has the number of cylender deal on the outside, there are 2 resistors and a tag that reads, "For 6-Cyl engines remove Bottom (Red) resistor"
ill get pictures when i get home today, for together to compleatly stripped.

 

Yep.....your tach may be old enough to not have a selection for a 4 cyl... Is the red resistor still there??? If so, maybe it's fried? If so, Radio Shack or a specialty electronics store (not Best Buy, etc.) should have one. They can match it up by the colored band sequence on the resistor.

 

Did the light ever turn on?

 

The correct hookup for Dixco tachs with 3 wires is:

Red - connect to a switched ignition source, positive (+).
Black - connect to ground (-).
Green - connect to the coil's negative (-) terminal.

Sounds like you have an internal problem... happens with age

 

He doesn't have a red wire.

 

I cut and paste from a Dixco instruction sheet without editting.
I don't have any Dixcos where I am now to check, but can check later today. Is the back similar to one of these two, and does the paper tag still show the model#? Both these had red power leads, but typically the green is signal, black is ground, and through the process of elimination, the white is your power (+) lead.

 

model number is 97.

 

I checked my Dixcos and they are all either black, red and green, or black red, and white. I took one of the 97's apart, and the board is different than yours, so I can't tell you for sure that your white wire is the (+), but if I was a bettin' man....
You don't need an adapter unless you're running a DIS ignition, so it still sounds like you have an internal problem.

 

I also have a couple of dixco tachs that I can't fiqure out. one is a model 3-5665 that appears to be the same as the one in this thread. I get nothing what I hook it up but the back lamp. When the green is hooked to the coil it does nothing. The other one I have looks to be a model 97, it is missing the green wire. Does anybody have a 97 that can tell me where the green wire connects in the tach?

 

Remove the back and take a pic of the board and (hopefully) I can match it up to a board I have. Is your 97 a blueline?

 

Here are some pics of the inside and outside of the tach that is missing the green wire.

 

btt.

 

bttt

 

Here are 2 boards I looked at this morning. Although the boards are different in appearance, the circuits appear to be similar. Hope this helps.

 

thanks that sure does.

 

I have a Dixco Blue Line 10k tach where all the wires have come loose from the circuit board. Anyone have a photo of which wires go where on the circuit board?
There is a Power and Ground (?) coming from inside the tach and then one wire from ground of the housing and one wire from the lamp, that far I am OK but then some or all of the should attach somewhere on the circuit board and there I am lost!
Thanks, /Johan

 

Trial and error... then I managed to get it to work. Realised I missed one of the resistors that goes on the back of the board so when I figuured out the value of that one it all fell in place.