Autometer tach in cj5

[blaylock6502]

I put an autometer ultralight 2 in my 74 cj5. It is very jumpy and inaccurate. I contacted autometer and they said to put a 10k ohm .5 watt resistor inline with the signal wire to try to buffer some of the noise. I plan to do this was just curious if anyone had run into the same thing??

 

[69jeepcj]

are you using resistor plugs? radio noise can come from non resistor spark plugs, not saying that is def your problem but very well could be. Not so important on newer cars but on older one,s you always had to run resistor plugs to cut out radio noise.