I just installed a 2.5" A/M tachometer on my '98 F250LD, and I owe it all to this group. The instructions I found by searching the older messages were excellent, the installation went without a hitch.

Driving in to work today, I tried to judge whether the tach. was giving me accurate information. The 4.6L engine seemed to idle at about 1000rpm, and cruise at 55mph in 4th gear (5-speed) at about 2000rpm. I shifted well before the needle hit 3000rpm. Can anyone tell me if these number seem accurate? My rear-end gearing is 3.55?

Thanks

John

 

find out what the computer RPM cutoff is... like 5,500 or something... put it in neutral and rev that sucker up till the comp stops it... then you know if its right or not...

 

Does your truck have the digital odometer? If it does, you can hold down the reset button before you start it, and continue to hold it down while you start it, and it will show your tach and other things on the odometer. You can do a search for more about that.

 

My dash uses the rolling drum style odo and trip...seems archaic.