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[Pony]

Hi, I have purchased Combo EGTS and Combo P, both in 24 volt, the pressure sensor is 3 bar boost sensor (auber 303)
I have wired them both with a common power and earth wire, I don't think this is significant, but have included it for completeness.
I wired the gauges and installed the sensors several days ago as a trial fit, I changed the EGT display to celsius and this worked fine, I then set the input type for the boost gauge to 1-5 volt (this was a mistake, I now know that it should have been 0-5v), set the decimal display to 000.0, the Pul to 005.4 (again this was a mistake, I now know it should have been -05.4), set the PuH to 048.9 and the gauge appeared to work fine, it displayed 0.0 or 0.1 at idle and when I drove it, it peaked at 14.1 psi at full load.  I don't know what the truck is supposed to boost at (Isuzu 6HK1TC motor), but I assumed that it was reading accurately.
I removed both gauges, but left the wiring to fabricate gauge holders and this afternoon re-installed the gauges.
Upon starting the truck, I noticed that the boost gauge was fluctuating between 69.4 and 69.5psi.  I immediately suspected that I had incorrectly installed a wire, so I checked all wiring and it was correct.  I again started the truck and it was the same reading.  I then went through the instructions, a bit more carefully this time and set the parameters to what they should have been, eg 1-5 volt and -05.4.  However this did not appear to make any difference it is still reading 70 psi at idle.
I re-checked all wiring several times and re-checked the parameters and all appears correct.
Now I don't know if the gauge was reading correct the first time I drove the truck, I believed it should boost a little more and this may be the case as I had several of the paramaters not set correct, however I do know that it is reading incorrect now, the motor definately isn't boosting 70 psi at idle.
The only explanation I can come up with is I have wired it incorrectly, as the only thing that has changed is I removed the wiring from the back of the gauge and then re-wired it again.  I didn't change the incorrect paramaters until after it was reading incorrect.
It is night now, so I will check all the wiring again tomorrow, but wanted your opinion in case there is something obvious I'm overlooking.  
Thanks in advance.
Brett DOYLE