2005 185.b, I have power to my dash and when i turn the key on the fan in the cab it turns, the exterior lights come on, dash is fully lit. when I sit in the seat it makes the little beep as it recognizes that someone is sitting in the seat. don’t even try to turn on tho. all the fuses are ok in the cockpit, don’t crawl on the engine and look at the fuses tho. Tried detaching the connectors for the seat safety switches and everything seems fine there.
Bad seat belt switch, I’d bet on it. I have one of the last L170s made, bought new 3 years ago as a reserve machine, and I have the same problem. When it happens to me, I usually get it on the third or fourth click, so try taking the belt off and on a bunch of times and it might come off. Mine goes on streaks, more or less when I’m fed up enough to change it, he doesn’t for a while. It costs like $ 180 because NH makes you buy the switch, the latch, and the belt strap.
If the run / service switch is put into service, does it light up? If not, it’s not necessarily the seat belt switch. And you don’t have to buy the whole expensive New Holland kit. Remove the female part of the seat belt and pry the box apart. Radio Shack has a switch that matches the two tabs on that set. All you have to do is cut the two wires and solder them to the RS switch, then bend the “lever” to match the old switch and POOF, you’ve saved yourself a couple hundred bucks. I think the RS switch only costs about $ 3. I don’t have the number on hand at the moment, just wrap the set back together with electrical tape.
If you start in the service position, it could be the seat belt switch. Does the board go blank when you try to boot it up? The positive battery cables were broken on our LS170s. We always kept extras because they never lasted long. They usually cause the screen and lights to go off when trying to boot up, but not always. We’ve been through a lot of starters too, have you tried arching it to make sure it’s okay? If not, the key switches sometimes break, as do the interlocks, and there are a couple of relays in the rear of the cab for starting. This is to my knowledge from the LS170s which may be different from your 185.b