I have a Bobcat 773 F series hand and foot controls. I need help with 2 problems. 1) It was blowing the 25 amp brake fuse, whenever the traction lock release button was pushed. It would work fine until you raised the seat bar or turned the machine and then you had to sacrifice another fuse in it to run the machine again. For a quick fix, I put modified a 25 amp self-resetting fuse to fit the fuse panel and it allows operation. 2) It just had the spool valves redone and a new emergency lift-arm bypass valve put on. It will work perfect for a couple minutes and then the lift and tilt will lock and the corresponding light on the BICS flashes 3 times intermittently. All other lights are normal and the forward and back controls work great. It was charging 14.5 (still in the green) with the old battery (800 cca) that I allowed to drain down will it sat for 6 months. The battery took a charge and has been starting the machine fine. I switched batteries to a 650 cca that my friend had laying around and it only charged 12.5 and the machine did not have any problems. So, I took the 800 cca battery out of my tractor and put it in the Bobcat. It was charging 13.9 and the lift-arm and tilt locked up again. I know that overcharging can lock the BICS, but wouldn't it also affect the traction lock? TIA, Duke
Given info provided I'm a bit stumped how the alternator reacts differently with the two different batteries, and that the machine has no issue when using the 650 CCA battery, but has traction lock and lift/tilt lockout problems when using the 850 CCA battery. I'd be tempted to continue using the 650 CCA battery for a bit longer to confirm that this is the case and not just a quirk the machine is doing making you scratch your head more.
Thanks Willie, Just to clarify, It has been blowing the brake fuse for some time now with any battery. The new problem is the lift arm/tilt issue. This has started since the spool valves were resealed. Is 14.5 volts enough to cause the BICS to go to system voltage and lock out the lift/tilt function. If so, perhaps both the 800 cca batteries are defective and causing the alternator to overcharge. Perhaps the 650 cca battery is healthy and does not cause the alternator to charge so high? I'm buying a new battery tomorrow and will see what it does now. In light of these clarifications, does anyone have any input? Please respond. Duke
If I'm not mistaken the brake fuse and relay controls the white "pull" wire of brake solenoid. The red "hold" wire and black ground wire is connected directly to the ECU. You may have either a faulty brake solenoid or bad relay connections at fuse box causing excessive amperage. Pull the brake relay from its socket at the fuse panel an look for evidence of melting plastic at the socket that relay plugs into. As for the battery, logic would say that if the 800 CCA battery is defective then you would have engine cranking problems. But machines have a way of placing logic on its head. Again, not enough history to be definitive, may not be a bad idea to install a fresh battery just to see how it affects things.
Thanks again Willie, I'll take a look like you suggest. I have a new brake solenoid here that I bought a couple years ago when this problem started. I put it on and the machine still blew fuses, so I put the old one back on thinking that I'd return it , but never did. I'll report back after new battery is installed and I check those relays/wire connections.
as willie suggested, the fuse blowing problem is likely the relay. f series relays are located above the battery. if battery voltage gets above 15v or so, ( or below 9v) the bics will shut off to protect itself. i'm assuming the valve light on the bics is whats flashing... you probably have a bad bics coil. they have a habit of breaking/ shorting the wires where they enter the molded plastic. may want to check that the harness connector at the bics coil doesnt have oil in it, and is securely connected. :drinkup especially after someones been working around the valve
Crewchief888, thanks for the response. There has been a lot of oil around that area and I've sprayed the area down with engine degreaser. I'll take that connection apart and clean it well. It is the one that is zip-tied and has a label on it that says "do not modify", correct? My wife is going into town (an hour away) tomorrow, so I might have her pick up a bics coil, just in case it is bad. I believe I replaced the relay for the brake when it first started blowing fuses and I bought and installed a new traction lock solenoid and it continued to blow fuses, so I placed the old one back in. Any other ideas on the brake? It would be the pull side that is grounding out. I don't think that the bics is shutting down from overcharging, because I'm still able to drive the 773 when the lift/tilt is inoperable and the light is flashing three times intermittently. Checked, both, my batteries which I tried and they have 12.50 volts. Both started the Bobcat and the tractor without incident, eventhough the alternator was outputting 14.5 with the original battery and 13.9 with the tractor battery per the bobcat meter. Thanks for your help, Duke
your machine should have the BICS coil on the control valve, facing the center of the machine, they came from the factory with an orange tie wrap "do not modify". i'm willing to bet, if the problem is intermittent, that once the coil is energized and gets hot, the ohm reading changes enough that the BICS controller shuts it off. if you are still blowing the brake fuse, i'd start looking into the backside of the fuse block, and the relay harness connector for corrosion or shorted wiring. :drinkup
Ok, replaced the bics solenoid, stem, o-rings and plastic nut. Hand tightened it with a 3/4 in. socket. The solenoid will still rotate on the stem. I haven't tried to see if my problem is fixed for fear that I will damage these new parts if I don't have it tight enough. I'm pretty confident that crewchief888 nailed it, as the solenoid crumbled apart and it was rusted to the stem. Please, someone let me know if this rotating of the solenoid after tightening is normal. TIA, Duke