Posted by C. Garbee on Friday, October 24, 2003 at 8:50AM :
In Reply to: datcom tach posted by Tim Holloway on Friday, October 24, 2003 at 8:05AM :
Normal at rest in my truck the guages (DATCON) tend to "float" and will not always be at zero. When carying them around prior to instal, they also "floated" around. When power is applied (turn ignition on) they go to zero (for tach and speedo) and to a level (volts, fuel, temp, etc) until the engine is cranked at which point everything works as you would expect.
I really like the DATCON units in my M37 with the Cumnmins 4BT.