EAS ECU? Knightmare!

Sorry for ANOTHER EAs thread!

2.5 DHSE P38 on 98'... Been into Hard Fault twice in as many weeks, and reset twice.. Have more or less searched it back to the Compressor not kicking in..
If i remove relay 20 and short it across to live, the pump runs.Run it till the tanks full and the EAS system all works ok..

Have checked the 3 fuses and relay under bonnet. All ok
Have checked the orange wire to the pump, and it is grounded, which indicates the Thermal Cut out hasnt cut in, stopping the pump?
Have checked the pin out 13 on the ECU under passengers seat and that is showing 1v (more or less empty tank), ( 12v relates to the pressure shut off valve thinking the tanks got 150psi in it)? So the pump should be being told to run?

All i can think of left is the EAS ECU? Is there any way i can test if its outputting the right signal?
At present im at running height with the Timer relay pulled out so as not to re-level... And ive not got any Faults showing on dash..

I do have another 2.5 DSE on a 96' i can rob the ECU outta to test,but will it lock that out or damage that?

Any suggestions would be greatfull as running outta ideas now!

Thanks in advance
Tel

what were the fault messages when you had it reset ?