Guardian 40kw ICM test

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markland556
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Ive got a 40kw Guardian 00492 genset. Got it not running. New battery, panel lights up, will crank but no spark. No pulse signal to the coil, but it is getting 12v. Mag pickup was tested at 990ohms and has an output signal.
Im trying to figure out if there is any diagnostic available for the ignition control unit. Its got a little green LED on it and what looks like a diagnostic pin header. Seems to be a propriety box, but a $750 gamble for a replacement seems like a big leap. Looks like the engine in this unit is a 3.9L Ford motor.
Any info would be greatly appreciated.
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Chris
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Do you have a serial number for the unit?
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Chris
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Also, that Ignition module is NO WHERE near $750! I sell them here: https://shop.gentekpower.com/products/g ... roller-pcb
Generac tech for over 12 years. I'm here to help!
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markland556
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Your right, i was looking yesterday and found some for that much. But it looks like they are more in the $400 range. Seems better now.
generac 0e8309
thats the part number right off the unit i pulled off the machine.

SN: 3953779

Chris: Thanks! Ya that unit looks the same. Let me know which one to purchase from you and ill bite the bullet. Seems like these go bad enough to be a safe bed. Your site mentioned something about a Diode. Maybe a safe bed to replace that as well. Dont see any blow holes on my board or swelled caps. But id rather take care of things before its dark and im outside testing things.
Chris
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So there is a diagnostic manual available for later versions of this unit (which did NOT have the external ignition module) but it does outline the procedure for testing the distributor and pickup which triggers the ignition coil and Ignition Module.

I called and confirmed there is no diagnostic manual for these, and they even went as far as to pull the engineering drawings to see if there were any notes about the LED and what it's for and the answer was no. The best advice I can give would be to eliminate ALL other possibilities first and then move forward with the IM.

If you look closely at the capacitors on the top, do any of them appear to have a blow hole? These units had a flyback diode which prevented field flash voltage from coming back into the 12V system and these would take a hit if that diode had failed.

You can check out that service manual here: https://shop.gentekpower.com/products/g ... tic-manual
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
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