autometer tach acting funny

[crustysack]

running 02 ls1 with an autometer phantom tach, backed my car out of garage to change oil and tach is not working,worked fine the night before, needle was sitting at 1.5k when I shut car off- usually drops to 0, turned car on tach stays at 1.5 untill I rev over that then goes up to my high rev but does not sweep just jumps up to say 3k will sit there then drop down but very erratic , needle will just jump to random spots on tach during acceleration, seems like something is binding needle up- all wires seem to be hooked up fine . any suggestions? tach has been in car approx 4 years- all other gauges work fine (all autometer)

[andrewb70]

running 02 ls1 with an autometer phantom tach, backed my car out of garage to change oil and tach is not working,worked fine the night before, needle was sitting at 1.5k when I shut car off- usually drops to 0, turned car on tach stays at 1.5 untill I rev over that then goes up to my high rev but does not sweep just jumps up to say 3k will sit there then drop down but very erratic , needle will just jump to random spots on tach during acceleration, seems like something is binding needle up- all wires seem to be hooked up fine . any suggestions? tach has been in car approx 4 years- all other gauges work fine (all autometer)

Did you ever install a pull up resister?

Andrew

[crustysack]

no I did not what ohm size should I use?- weird that it has worked all this time though
I am seeing a 1k 1/4 volt resistor sound ok

[crustysack]

tried the resistor -did not help- would anyone know what the output signal should be from the tach wire so I can test that??

[OG_Racing]

When my alternator was going bad my tach acted exactly the way you described. jumped around like a mad man then laid down. after that my voltage would start falling. i was 10 miles from home when it happened. i would get a jump and drive, get a jump and drive. after a while i realised, when i saw the tach give out it was time to pull off the road.

[crustysack]

having no charging symptoms-

[OG_Racing]

having no charging symptoms-

maybe check the connection to the 12v power source.

[crustysack]

Getting power and a signal from tach wire called Autometer and they said to send it to them and they will look at it. So off it goes

[Yukon Cornelius]

I know it is an old thread but what did autometer have to say?

[andrewb70]

I know it is an old thread but what did autometer have to say?

He has not been online for a year and a half...

Andrew