ScanGauge Questions..mine came in the mail today

[GasSavers_FordF150]

Okay so my ScanGauge showed up in the mail today and I plugged it into my truck after turning the truck on and....nothing, notta, zip, ziltch.
So I plugged it into my wife's car. Seemed to go acording to the diagrams after 20 seconds or so it went to the home screen. I set it up as best I could for her car and drove it on the hwy and then into town.
Just checking to see if this is the norm.
The MPG gauage was jumping from as low as 7 to as high as 57 and everywhere inbetween the entire trip.
Except for when I put the cruise on on EXACTLY flat long distances it was up and down every few seconds.
Is this the way they usually are? Even a slight hill up or down made a significant change on the MPG guage.
Also any helps with why it isn't working on my 2003 Ford F150 4x4?
I tried it several times waiting and waiting and waiting, but eventually (2-3 minutes later) just shuts itself off to nothing on the screen everytime.

[theholycow]

Instant MPG readings, whether from a Scangauge or an OEM display that came built-in to a car, vary from single digits to over 100mpg during normal driving. That's true in small and large vehicles alike. Trip and tank averages are more useful.

It sounds like there is something wrong with your truck's OBDII connector.

[VetteOwner]

did any ever need additional power? or are all OBDII conectors powered thru it?

(some OBD1 need power from like the cigarette lighter to work when u hook it to a scanner...)

[GasSavers_FordF150]

No other wires except through the OBDII port

[Bubba Bob]

Fuse Check.

[theholycow]

I thought fuse too, but "I tried it several times waiting and waiting and waiting, but eventually (2-3 minutes later) just shuts itself off to nothing on the screen everytime" tells me that it powers on in the truck if the button is pressed, so it's getting power at the OBDII port.

I suppose there could be a separate fuse for the signal going to the OBDII port.

[Bubba Bob]

Won't it come on w/o being plugged into the OBD port if you hit a button? I really can't remember...

[theholycow]

No, it doesn't have a battery.

[FrugalFloyd]

You have to crank the engine over on some cars to get the car to communicate with the ScanGauge. Once it's communicating, you can shut the engine off, then turn the ignition switch back to the "on" position, and it should stay communicating during setup.

[GasSavers_BEEF]

Sentra SE-R, I second that

plug it in and drive down the road. maybe let a buddy drive and you can play with it.

once you get everything straight with it, set up an X-gauge to show trip-MPG. this will reset after your ignition is off for more than 3 minutes (or there abouts) this gives you a running average of a particular run like for example your trip to work.

another small note: when you do get it working in your truck, there is a calibration procedure. this is very important. put in your displacement and follow the instructions for the offset (it's all in the cheesy manual)