Combines 4420 auto header height

[trun]

Are you sure its a solenoid problem

 

[TwinRotor]

We used to able to short the wires at the end of the plug and make it go up and down now it wont do that.

 

[JHEnt]

The control valve under the platform step has manual pushbutton controls also. Basically a small round metal rod visable from the center of both the raise and lower solinoid coils. With the engine running you can push on that button with a screwdriver and make the head raise or lower. Electrically if it doesn't work at all then there is a fuse located in the engine compartment behind where the dash is in the cab. Also the feederhouse hight cut out switch likes to go bad. Its a simple spring return pushbutton switch with a rubber boot. Its activated by the small chain tied onto the feederhouse under the cab. This stops the power before going down to the header connector so if its bad the AHHC won't work at all.

 

[TwinRotor]

I'll have to look into that, but I remember when we got the combine it would raise and lower fast then it gradually got slower on its own. We've had it worked on before but that didnt seem to help much. If you have any more ideas let me know, this combine has 2800hrs on it.

 

[JHEnt]

Could be a problem with the power-beyond fitting in the main hyd valve. This is the line comming out of the main manual valve and feeds oil to the electric valve. In a normal PB system the fitting would just be a straight thru fitting, meaning it would be the only path for oil traveling down the main galley in the manual valve for the oil to leave by. However in this system it contains a spring loaded plunger with a drilled orafice thru the plunger. Basically because the electric valve is a closed center type when the electric is not active the plunger lifts off its seat and allows the oil to pass thru holes drilled in the side of the PB fitting and into the normal return gallery of the manual valve at minimal back pressure. When the electric valve is active, the oil flows thru the orafice down the center of the plunger to the electric valve. When oil can pass that way the plunger moves back against its seat to prevent oil from passing into the return gallery of the manual valve. This way the electric valve has enough pressure to operate the header. So if the spring is too weak there will not be enough pressure going to the electric valve to make the header raise or lower. The electric valve opens pressure to the cylinder to raise and has a lock valve block bolted to it that requires pressure from the other outlet port of the elcetric valve to unlock the head and let oil out to lower.

 

[firefarm]

Good informative post.

 

[TwinRotor]

If I try the manual buttons on each end of the solenoid and those dont work, chances are theres a problem like you stated above. Do you see these solenoids go bad thoughIJ

 

[JHEnt]

I don't think those old solinoids hardly ever go bad. I installed AHHC on my 4400 with parts I got out of a salvage yard. I also put one on my grandfathers previous 4400 that he later traded for a 4420 and on a gas 4400 that we shared to do corn with. I put the AHHC on the gas one with the idea of using it for beans before I bought the diesel 4400 I still own now. So over the years I've put 3 systems on older combines. If the manual push buttons get no response from the head then you have a pressure problem with the PB fitting.

 

[TwinRotor]

I did some more testing today, both electrical plugs work because it would at least raise when i used both of them on the raise side. I had no response out of the lower side no matter what power plug i would use, another funny thing is the manual push buttons would not work even though I could get it to raise with power.

 

[joe]

I am suprised it works at all without a header. Do you have the single on_off control, or the 3 position controlIJ what does it act like when the header is on, and the wires hooked upIJ