The olss is in H I think the man I bought it from said not to move the olss switch off of H that the tvc solenoid didn't work wright. Now the red and green light in the controller are blinking (speed sensor) if the solenoid does not work and the speed sensor is bad will it not cause the engine to over heat? I have not been able to find the prolix switch its not on the controller and I can't find it in the cab the manual does not say where it is that I can find. If the solenoid does not work would it do any good move the prolix switch? A lot of questions but I have been trying to figure this thing out for over a year now. Please somebody help this poor old fool !!!
The prolux switch is underneath the controller hidden by some sheet metal. Check the oil in the bell housing by pulling the little square headed plug under the pump. That is the level that the oil should be at. If it is over full, you need to drain it to the correct level. Check it again after a few days of running an if it is over full again you have a leaking rear main seal on the engine and probably the input shaft seal on the pump. The bell housing being full of oil will get it so hot the paint will burn off. You can check the speed sensor with an ohm meter. On a bad one the needle will either not move or swing all the way to zero. A good one will show somewhere between two to six ohms. The H mode will make no difference when the speed sensor is not working. The prolux switch will give you about 75% of the available power the engine can put out. When the TVC solenoid fails they usually burn out and the plunger doesn't move. As I recall the pump will not fully stroke up when that happens but I could be wrong on that. I know unhooking the harness connector to the solenoid will put the pump in max output and make the machine so jumpy you can't control it anyway. It could overheat the engine. Good Luck!
Thanks John c. the controller is located in the compartment between the cab and pump compartment it the one with the lights on it wright? Do you have to take take the four screws out of the cover and remove it (controller) to get to the switch? I can't see anything else you could remove to get to it.
As I recall the toggle switch is underneath that box on the frame. If you can stick you head down there you should be able to see it. It is protected above and below with a sheet metal tab.
John C. I found the toggle switch and I get 20v to the tvc solnoid and the plunger pushes out with the switch flipped. No volts in normal position to the tvc solnoid. The speed sensor shows to be bad. With the toggle in normal position I get no volt with the key on but If thd key is off and you turn it on the solnoid plunger pushes out just as it does with the bypass switch flipped does that make sense?
Those pumps use oil pressure to destroke them so when you start up the plunger is pushed out so the starter doesn't have to turn against hydraulic pressure to start the engine. As soon as the engine starts and the computer gets the speed sensor signal it will back the plunger in. It sounds like the electronics are working correctly. Have you checked the oil in the bell housing yet? As I recall the speed sensor isn't all that expensive to replace. I've drained the bell housings and put a pan underneath the drain plug and ran them that way. Good Luck!
The plug was out of the bell housing when we got it. With the speed sensor not working and it in H mode and by pass set to normal would the controller go into oil sensing mode to control the pump pressure? The solnoid would not move with the key on when you moved the olss switch with the by pass set to normal but would it if the controller sensed the speed sensor not working?
I forgot to say I have not run it with the by pass toggle switch as of yet to see if it helps heating problem .
On the Dash 3 series machines the H mode makes the controller interactive with the speed sensor. Basically as load is increased the engine will slow down. As it slows the computer senses this from the speed sensor and pushes the plunger out to de-stroke the pumps enough to let the engine speed raise back to normally. What happens is the the hydraulic functions will slow down. The Dash 3 machines, as I recall, are a little crude in that the S and L modes simply limited the total voltage supplied to the TVC and were not interactive. The Dash 5 machines were totally interactive in all three modes. The prolux mode simply bypasses the computer and supplies voltage through a resister to the TVC. Now then your primary problem as I understand it is the overheating of the engine coolant. The Dash 3 machines had two issues that caused overheating. The first was the space in between the radiator and hydraulic oil coolers would get full of dirt and debris thus plugging air flow. On the Dash 3 machines there was no plate under the radiator that could be removed to let the dirt drop out. To properly clean that space you had to take the hydraulic oil cooler loose and use a shop vac to pull out the garbage. The second problem was the foam seals on the side and top of the space between the radiator and cooler. They got torn out over time and this would let cooling air go around and not cool the hydraulic oil cooler. I have a fair sized compressor that I used to blown out the coolers at least once a week. I got a four foot section of 1/2 inch pipe, a butterfly valve on one end and a pipe plug with a hole drilled in it installed in the other end. It takes about twenty minutes of busting the dust up to get the coolers clean enough to keep the systems cool.
I have taken the radiator off and had it rodded out and put a new thermastat in as well. I'm going to check ohms on the speed sensor and be sure its bad before I order one and then go from their. I'm going to run it with the bypass toggle switched when I get a chance and see if it changes anything.