1999 jlg 450 aj serial# 0300039013. Not all functions work in platform, boom up/down, speed control. It stops functions after 7 seconds, ground controls al work. I swapped out the lift/swing card speed control the time delay boxes and the level indicator from our other machine and made no difference and the parts worked on the other machine. Ignition switch was replaced by previous owner gonna double check that wiring, also swapped out the foot pedal and made no difference. Has hydraulic fluid. Looking for suggestions where to look or test next. Thanks
Checked ignition selector switch witch is fine, tested the switches in the platform they all work as should gonna test the relays and the the wiring to them. Did a continuity test on the wires coming back thru the boom to ground box , some wires i multiple signals on but i didnt remove individual wires from the buss bar. Still open to any ideas. Thanks
If all the functions work from the ground, that tells me it is an electrical problem. If it only works for 7 seconds, I would suspect problems with the foot peddle. Maybe not problems with the peddle itself, but with the wiring to or from it. Check the output of the functions that do not work at their switches. If the switches have output, than start following it down until output stops and hopefully you find the problem. If there is output from the switches at first, but then it stops, there is likely a problem with the enable circuit/foot peddle. Make sure it's output is not going away after a little.
Update: bypassed the 7 second delay timer with a plain relay ( 7 second timer delay works in other machine) have gotten other functions except the swing only works 1 way from the platform but at ground it works