What problem are you having with an LN 9000? I had a couple some time ago, I found out some of the circuits are ground activated , right backwards of most trucks , My e- mail is
[email protected]. if you need further assistance, I started using aftermarket parts ( Horton fan hubs etc.) and wired some components reversed, through Bosch relays. I called mine a "Poor Boys' Peterbilt". most parts were captive market . Check the cab feed relay same as some 70s thunderbird headlight relays, tin box about 1""x 1 1/2" 3 wire plug.
Fordestes