Whacky tach

[mleach72]

My tach had been acting funny for quite a few years. Sometimes it would act normal, but other times it would be bouncing all over the place. Other times, there would be no lights at all. Sometimes all the light would be lit, and sometimes they would be flashing like I'm idling too low when I'm cruising at highway speeds. I always figured that I needed a new tach ring, so I never really worried about it much. A few weeks a go, I noticed that my oil light wasn't coming on when I shut the engine off. I took it apart and found that the oil light wire had broken at the solder joint. I got a new tach ring from Eric and installed it. Oil light works now, but tach is pretty much the same. Any ideas where I should start looking?

 

[knothead]

My tach had been acting funny for quite a few years. Sometimes it would act normal, but other times it would be bouncing all over the place. Other times, there would be no lights at all. Sometimes all the light would be lit, and sometimes they would be flashing like I'm idling too low when I'm cruising at highway speeds. I always figured that I needed a new tach ring, so I never really worried about it much. A few weeks a go, I noticed that my oil light wasn't coming on when I shut the engine off. I took it apart and found that the oil light wire had broken at the solder joint. I got a new tach ring from Eric and installed it. Oil light works now, but tach is pretty much the same. Any ideas where I should start looking?

I would check around the ignition module and the coil and the harness going to the tach...might be a bare spot in a wire rubbing or possibly a connector in between all of those items and see what you find

 

[mleach72]

I would check around the ignition module and the coil and the harness going to the tach...might be a bare spot in a wire rubbing or possibly a connector in between all of those items and see what you find

Thanks, I looked for bare wires before when I had things open, but not extensively. I'll look at it tomorrow and try to do a more intense investigation.

 

[knothead]

Thanks, I looked for bare wires before when I had things open, but not extensively. I'll look at it tomorrow and try to do a more intense investigation.

I figured you looked already....only thing that comes to mind would be ignition module and the coil wiring...now that i think about it your plugs wires can make it do that too....i seen like the twisted wires and some of the other aftermarket plug wires make a tach act crazy and also saw the wires getting old and deteriorated do tge same thing...for shit and giggles if you got another set of plug wires on hand try that

 

[mleach72]

I figured you looked already....only thing that comes to mind would be ignition module and the coil wiring...now that i think about it your plugs wires can make it do that too....i just remembered this lol....i seen like the twisted wires and some of the other aftermarket plug wire make a tach act crazy....for shit and giggles if you got another set of plug wires on hand try that

I didn't think of that. The plug wires are original as far as I know. Do they go bad?

 

[knothead]

I didn't think of that. The plug wires are original as far as I know. Do they go bad?

Yeah plug wires do go bad over time..

There is something thats causing a interference making the tach go wild...i just keep getting the feeling the plug wires are causing this....i might be wrong, but wont be the first or my last time if i am....

 

[mleach72]

Yeah plug wires do go bad over time..

There is something thats causing a interference making the tach go wild...i just keep getting the feeling the plug wires are causing this....i might be wrong, but wont be the first or my last time if i am....

Yeah, that makes sense. I just ordered a new set of plug wires from Eric. We'll see what happens.

 

[knothead]

Yeah, that makes sense. I just ordered a new set of plug wires from Eric. We'll see what happens.

I would still check the wiring to make sure nothing is wrong while you still got all that open to look at....

 

[mleach72]

I would still check the wiring to make sure nothing is wrong while you still got all that open to look at....

Thanks knot! Got the new plug wires put on and the tach is working normally for the first time in years! I love this forum! I never would have thought about changing the plug wires.

 

[knothead]

Thanks knot! Got the new plug wires put on and the tach is working normally for the first time in years! I love this forum! I never would have thought about changing the plug wires.

Good deal buddy....glad that got you all fixed up

 

[Fitter]

this is interesting. my tach has just recently started pegging out to normal for no reason. Time to check plug wires.........