Trane RTU issue

[SeanH]

Model: YSC092A3ELA13D

Cannot figure this thing out. No cooling call. Turned unit on and fan would come on and both compressors would come on then turn off. Gauged up, found high head pressure, washed the condenser good. Head pressure came down and started running and cooling for about 20 minutes. took the cover away to take gauges off and the damn thing turned off again and never would come back on. Started checking for an intermittent HPCO issue but found none. Bypassed every pressure cutout to see if they were causing the issue, no luck. Also bypassed freeze stat to see if it was opening. No luck. Now all it does is jog the blower when I apply power for a second or 2 and then nothing. What am I missing here? I didn't see anything else on the barely readable schematic that would cause the contactors to shut off. Any suggestions? Thanks in advance my friends.

[2sac]

How long is never? ASD delays in both the tstat and rtu could be your problem.

[SeanH]

Every 5 minutes or so it would try to kick on but would immediately shut off the blower motor. I usually only work on refrigeration systems. Not up to speed with these trane units. Tech support is hard to get a hold of.

[revg62]

air proving switch on blower? revg62

[michael013]

Will it run in "Test Mode" ??

[michael013]

Hope it's allowed to post this since your diagram is not readable......

From Trane:

Simply place a jumper between Test 1 and Test 2 terminals on
the Low Voltage Terminal Board and the unit will walk through its
operational steps.

[buzhall]

I had one at a furniture store doing the same thing.one of the low voltage fuses was loose in the holder. It would wiggle itself open. try to keep it simple.

[timebuilder]

ALL of the screws in the TB 1 strip have to be tight. The test screws won't work correctly if they are loose, and the safeties are wired through the others.