Update:
Truck has had its ups and downs...okay, mostly downs over the last few years.
About to have it all running correctly and tuned...but...
this gauge issue is STILL like this.
Lights OFF = Gauge OFF
Lights ON = Gauge ON
I contacted AeroForce back when I originally posted this thread and they didn't have a clue either.
Any ideas?
Thanks!

 

Does it do the same thing in somebody else's truck?

 

Don't know...but never did it in my truck either for a couple of years.

 

Get a test light or get a meter. Its a blown fuse or a fused link. Check for power at the obd2 connector. If no power check all fuses in side of dash and under hood. Good luck. It could possibly be a relay

 

Power @ obd2 port was confirmed last night.
Old DiabloSport Predator powers right up when plugged in, as well.

 

What happens if you tap a dedicated ground from the OBD port to the chassis when the ScanGauge is not working?

 

Sounds like a bad gauge

 

E-mail reply from AeroForce:

 

Update:
Ordered a new cable...installed...problem solved.

 

I have had two sets of these Gauges and both started having connection problems. When the first set started giving me problems I noticed the pins seemed loose on the OBDII connector. I split the connector open and found cold solder joints, re-soldered all the pins and the problem was resolved. Same thing when the newer set started acting funny.

I unplugged and plugged mine in a lot with all the flashes and scans and figured that could have caused the solder connections to crack.

If they start acting up again try re-solder the connections first.