Miller AEAD-200LE

[ShaneT]

Hello, I am new to the group. I'm not sure how this works but here goes. I have a Miller Legend AEAD-200LE. The problem started with the auto idle not wanting to speed up when I struck an arc and then it got worse. Now it will not strike an arc unless you put the switch to the turtle/rabbit position and try to strike and arc at idle then flipping switch to the rabbit position and then it will weld until you turn it off. If you fire it back up it may start welding fine or you may have to fool it again. Thanks for any help with this problem.

[D Auger]

bump

[Aeronca41]

Please post your serial number.

[ShaneT]

Serial # JH290524 Thanks

[Aeronca41]

I'm not sure if this welder energizes or deenergizes the idle solenoid to go to weld power; maybe one of the experts will join in with that answer. If you are not trying to weld, but turn the switch to rabbit, does it speed up? is your issue one of engine speed, or the machine not delivering welding power even if it's up to speed? How about the power outlets? Does it provide power to run your grinder when you have all the controls set correctly? Do you have the manual? If not it's available here

https://www.millerwelds.com/files/owners-manuals/O411P_MIL.pdf

You may need a Kill-a-Watt meter from Home Depot or a multimeter with a frequency (Hz) range to verify engine RPM before this is finally fixed.

[duaneb55]

I'm not an expert but the throttle solenoid of the AEAD energizes to increase engine speed to the WELD rpm of 3000. The problem could be a faulty AUTO IDLE switch, faulty POWER/WELD switch, faulty circuit breaker CB1, or one or more poor connections at the idler control board PC1, above mentioned switches, throttle solenoid, ground to the AUTO IDLE switch or idler control PC1 terminal "J" or any number of connections within the idler circuits. And of course you could have an intermittent fault with the auto idler PC1 or current transformer CT1 although failures of these devices are typically final and not intermittent.

For your troubleshooting needs, the way the system works is:

1) Battery (+) power is supplied to the throttle solenoid and idler control PC1 terminal "B" from the WELD/POWER switch in the WELD position thru circuit breaker CB1.
2) Battery (-) is supplied to the throttle solenoid to increase engine speed to WELD rpm from the idler control PC1 terminal "C" when a weld or 100Hz outlet load is sensed by the CT1 which applies a low AC voltage to the idler control PC1 on terminals "F" and "H".
3) Battery (-) is also supplied to the throttle solenoid for WELD speed from the auto idle switch in the OFF or rabbit position keeping the engine at WELD rpm as long as the WELD/POWER switch is in the WELD position to supply battery (+) to the throttle solenoid.
4) Placing the WELD/POWER switch in the POWER position removes battery (+) from the throttle solenoid thus preventing it from energizing to increase engine speed to WELD rpm.


It should be noted that Miller designed the AEAD throttle control system this way which is directly opposite from their typical auto idle systems where the solenoid energizes to reduce engine speed to the low idle rpm.

[ShaneT]

Thanks for the help. I will try to look into it this weekend and will get back to yall.

[ShaneT]

Sorry guys I got busy and I just got back to the welder. I checked CB1 and CB2 they checked out ok. I replaced CB3 only because I broke it. I then replaced CR3 and CR4 because CR3 was arcing bad and that fixed the welding problem but the auto idle still will not work. Thanks, Shane

[ShaneT]

Hello guys the machine is welding fine now when i put the ignition switch in the manual full throttle mode but when I put it in the auto mode it will not speed up when arc is struck or grinder is turned on. I'm trying not to pull my hair out but I'm not sure what else to check. Thanks for the help

[ShaneT]

I forgot to say that I have the -negative to the solenoid but I have lost the + positive side.

[ShaneT]

Thanks for the help it turned out to be the idle control PC1