900H Compressor loading during warm up.

by Morgan
(Trinidad and Tobago)

I have a 900H compressor that is loading before the warm up cycle starts to 125psi which normally is 65psi.

I checked the Start/run solenoid and it seemed to be good.

I went a step further and changed out from a working machine and the same issue occurred.

I check the minimum pressure valve to see if it was stuck in the open position which also was not the case.

Is there something else that I can troubleshoot to resolve this issue?

Comments for 900H Compressor loading during warm up.

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Mar 07, 2018
Air block
by: Anon

One of the other ways to fix the loading issue is to check the air block. There may be some blockages causing the air to by-pass and go to the load cycle.

You may need to re calibrate the block valves as well.

Nov 29, 2017
900H compressor
by: Dan

I have the same problem at start up it is loading during warm up check everything changed even diagnostics board still no change, anybody got any ideas thank you

Jun 29, 2016
Compressor loading solution
by: Bill

Thank you Morgan for taking the time to update your question, and to help others that may have the same compressor problem. Cheers!

Jun 29, 2016
Problem found
by: Morgan

After going further into the issue I have found that the current was not coming into the magnetic solenoid. When tracing back the wires in the diagram there is a relay which was not getting the current to activate it. The signal is supplied from the compressor and engine warning/shutdown circuit board found behind the instrument panel. I swapped the board and the machine is working properly and has all the correct PSI's.
Thought I would put the answer up incase anyone else has the same issue in the future.

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