AEAD-200LE AutoIdle not working

[tbert]

I have an AEAD-200LE Ser #JH149645 that won't come down off HIGH idle.

I have the Manual and it says that 10 sec's after you stop welding...or shut off the tool you are running using the 115v/100hz outlet, it should kick back down to IDLE.

I bought it fairly cheap but not running. It turned over but wouldn't fire up.

I put all new wires/points/plugs/fresh gas and it fired right up. I haven't tried welding w/ it yet, since the ends on my welding leads are different, but just to try out the AUTOIDLE feature, I plugged an angle grinder into the 115v/100hz outlet and ran it. The welder kicked up to HIGH idle like it was supposed to...but it didn't kick back down to IDLE again after 10 sec, like the Manual said it would.

I have the Miller OWNER'S MANUAL, also the Onan Operator's & Service Manual for this machine, and this is not covered anywhere.

I have it set properly,[using Manual], in WELD position...w/ AUTO IDLE "ON".

I've tried it several times, and let it run for several minutes to make sure it's not just delayed w/ age. I've re-read the Manual. It never kicks back down.

It kicks back down to IDLE as soon as I throw the switch from WELD to POWER tho. Also - when I then click the switch back to WELD, it stays at IDLE...till I hit the trigger on the angle grinder again.

So - my question[s] to you folks is: First- is this dangerous, obviously,... but next, How do I fix it?

Thanks.

[duaneb55]

Check for a good connection at idler board terminal J and good chassis ground connection to wire #33 of same.

If that's not it, PM me with an email address.

[tbert]

duanne.

I checked the connection on 'J', that was clean and tight... also checked w/ continuity light from "J" to chassis ground [while the wire connection was on it], and I had continuity to ground.

Thanks for your response. Those two things checked out...I'll see if I can PM you...

[duaneb55]

PM received and email sent.

[tbert]

Duane,

Thank you for such a fantastic response. Now I'll hopefully be able to figure out anything that happens w/ this weld/gen.

This site is the best.

[duaneb55]

Hope it helps. Let us know what you find.

[tbert]

Thanks to duane, I'm now using the "Technical Manual" for this machine to troubleshoot my OP problem...

so...here's a question -

Sec.10-4,#15: "Start engine, and place S4" [AUTO IDLE switch] "in the ON position, rotate FINE AMPERAGE control R1 to minimum and short circuit the weld output"

... then do further meter-reading measurements around the side of machine at the Auto Idle Control Board...

-how exactly do I do that? If I 'short circuit the weld output', isn't that striking an arc? & If I'm striking an arc, how do I troubleshoot at the same time?

I don't know if I should just put a jumper directly to frame of machine...or?? Seems to me that as soon as I 'short circuit', or ground, that weld-output jumper anywhere, the machine is going to want to weld! i/e=the rpm's will jump up,etc...but - then it will just be stuck there in the 'wanting-to-weld' mode, just like if your electrode gets stuck to your work. Isn't that a harmful condition for the machine to remain in?

Please excuse my short-sightedness here...i just don't get it. I have an electrical background...so the "short circuit" terminology just sounds like a bad idea to me. Once something "short circuits"...everything involved in that circuit starts heating up till the weakest link gives out.

If the machine WASN'T running, that would be different. But it clearly states as above to "start engine".

Does "R1 to minimum" take machine out of weld mode?? [I kinda doubt that - but what do I know].

Again, this is a clearly defined testing procedure laid out in black & white in a Miller Tech Manual, so it is obviously safe? So - how do I go about it?

Thanks for helping.

[duaneb55]

Well, you've somewhat answered the question which is to "short circuit" the weld output just "stick" a rod to a scrap piece of material. This is no different than putting the machine on a resistive load cell for testing.

The reason for setting the Fine Current control to minimum is to keep the load down for the recomended test but doesn't take it out of weld mode as you've suggested. The rod is the "weak link" and will definately get red hot if your test takes too long.

So, get everything set up and ready, fire it up, stick the rod (on minimum that shouldn't be too hard) and get the requested test figures then shut it down (or unstick the rod - if you can ).

[tbert]

Thank you AGAIN, kind sir!

It sure does seem like a 'scarey' way to run the test, but I'll give it a whirl. I have visions of donning the welding helmet, etc... getting the volt-meter ready...side panel off the machine...def going to be a "candid camera" moment!

Life may have me tied up for next couple days, but I'll post back w/ the results asap.

IF I understand a little deeper reading into the Tech Manual...it seems to suggest that my AUTO IDLE CONTROL BOARD PC1 may be the trouble. If that is so, any chance these may still be available?

Thanks so much for all the support thus far!!

[duaneb55]

Aftermarket units are available but likely yours can be repaired for little $$ if it proves to be defective.

[pothole]

I am also having the exact same problem. could you help me out also duane.

[tbert]

Just wanted to post back again w/ an update...

I hooked machine up w/ proper welding leads, even did a little welding w/ it to try it out...then followed the test procedure, I shorted the weld output and took some meter readings...it def seems like it is the PC1.

Everything still remains same as in my OP.

I don't know how to delve in any farther at this point.

I've taken the correct readings that the Manual calls for, and I'm up to this point:

"Sec 10-4, 20[a]; If TS1 remains energized when load is removed, remove lead from PC1 terminal C. If TS1 remains energized, repeat Steps 1 thru 19. IF TS1 deenergizes, the problem is probably with PC1."

I also seem to be having a bit of a carb issue, as I have to run it about half-CHOKEd to keep it from chugging at IDLE. I think tomorrow I'll throw on the carb rebuild kit that I purchased w/ the other tune-up parts and see where I'm at then.

If this is not resolved, and machine stays on HIGH IDLE during the weld process [until the WELD/POWER switch manually flips it back to IDLE], how detrimental is this?? Is it merely a case of wasting fuel??

Thanks a bunch...I'll let you know how I make out!

[duaneb55]

Because the throttle solenoid is energizing with a load applied, there is no need to proceed with troubleshooting steps 20-22.

What I can tell you is that PC1 thyristor SCR50 isn't unlatching after the load is removed which is why the solenoid won't release until you select POWER mode (removing power from the board). What I can't tell you is which drain resistor, if timing capacitor C53 or which other board component may be at fault from a distance.

The only detrimental result is as you suggested regarding using more fuel and perhaps the annoying fact that it won't idle down.


As for the engine issue, you may want to check the valve adjustment as well. Insufficient intake valve clearance can result in reverse pulsing in the intake that can result in irratic speed that may be "corrected" by partially closing the choke.

[tbert]

Thanks duane, I just needed to post back here to thank you for all your help!

As Im sure you suspected, life has thrown me a few curveballs, & I haven't been able to get back out to the shed to do the carb tear down yet. I was kinda hoping to get the engine squared away first before I got any deeper into the IDLE problem.

I didn't mention it...but when I ran it and welded w/ it, it didn't weld so hot in the upper AMPERAGE ranges. The arc wasn't very stable at all & seemed weak. Lower ranges seemed pretty normal tho. This has me concerned that more things could possibly be wrong. {?**

Manual states that if ENGINE isn't running well, then the resulting loss of power will effect the performance of the welding. So I figured I should iron this out first,that's all.

I'm so glad to receive your tip to check the valves also, that way I can eliminate any bugs w/ the engine...then when THAT is satisfactory...i can work from there on these other issues.

Do you think the local Airgas or other weld suppliers could take care of my PC1 issues? Or is that a Miller-exclusive repair?? I obviously don't mind waiting a bit for it, if I knew who to send it to, since it sits in my shed for long stretches at a time.

Thanks again, you're a TREMENDOUS help. I hope I can tackle this before the snow flies...gr

[duaneb55]

Well for a little over $100, David Herbert over at Weldtron has his aftermarket replacement for the AEAD idler control board (WT-70477) if that sounds like a better option for you - after the engine issues are corrected.

http://weldtron.com/products/Product%20List.htm