|
By Melly - 5 Years Ago
|
|
Just took old tach out to do a check on RPM. Connected the green wire to Dist. and Black wire to ground on batt.. Tach. had no reading. Went to grab ground and notice small amount of voltage at connection. This does not seem right. Connected ground to motor still nothing and voltage still on connection. Then touched red wire to Batt. Pos. side and tach. worked. Am I missing something, did not think that needed power source just to us. And don't understand the current through ground connection. Any help with this.
|
|
By bergmanj - 5 Years Ago
|
Melly,
I can't speak specifically to your Tach requirements; but, whatever circuits you have [sense, power] need a return path - ground; if there's current flowing, you'll get a spark when connecting "ground"; this is normal.
Regards, JLB
|
|
By Dave C - 5 Years Ago
|
I thought most tachs had 4 wire hook ups. Red - switched power, Blk - ground, Grn - Coil Neg, Wht - dash light.
At minimum Red, Blk, Grn.
Dave
|
|
By Melly - 5 Years Ago
|
|
It does have the four wires you mention. I was trying to just hook up and it under hood,, I put Gr. on the neg of coil, and then connected Blk. wire to battery. This is when I could feel the current in the end of ground lead. And that caused me to wonder if that a problem was moving Blk. to a different ground. connected read wire to Pos, battery post and tach. seemed to work fine. The current in making the Blk. ground connection is what I am wondering about. Done with motor running. Maybe I am just to crazy but did not seem right to me. Then again never touched the lead before for grounding. Thanks for having patience with me I do all info hear very helpful. Love the Y Bock just wish I had better knowledge.
|
|