national crane 800d LMI problem

i have a 2 blocking issue or appears that way..ive checked relays, switches, wiring on boom side(truck mounted unit) with no luck..even with the lmi key turned to bypass mode the unit stays twoblocked..any help wil be appreciated..thanks in advance

I’m not sure about your machine but the ones I’ve had had solenoid that holds the hydraulic circuits open they can fail or corrode I have taken them apart and cleaned put them back in to get me going then order a new one

THANKS IM ABOUT TO HEAD OUT TO JOBSITE AND TAKE A LOOK.. DO YOU KNOW IF THESE SOLENOIDS WILL WORK OF POS OR GROUND..FOR TROUBLSHOOTING PURPOSES OR TO BYPASS ANY OTHER ISSUES AND WORK BACKWARDS FROM THERE?

AFTER CLEANING THEM AND TRYING THAT OF COURSE..

The ones I’ve experienced have be energized to hold the circuit open so they remain on the whole time you operate versus activating for functions. I’m not a mechanic but I think that would make it hard to bypass. On my old one there where two side by side the second one I think was the two speed winch that got seldom used I swapped them out and away I went. Please take my advice for what it’s worth I’m a master carpenter and a good crane operator, but a poor mechanic. Lol

THAT HELPS ALOT TRADESMAN I SO OFTEN FORGET ABOUT THE "OL' SOLENOID SWAP" TRICK..I MYSELF AM NOT A MECHANIC EITHER..IM A LOGGER/TRUCK DRIVER BY TRADE I GUESS..I KNOW JUST ENOUGH ABOUT A LOT OF THINGS TO GET ME IN TROUBLE THATS FOR SURE! THANKS ILL LET YOU KNOW WHAT FIND OUT