Flashing over speed red led

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g&bporcelain
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Mon Feb 11, 2019 5:07 pm

I have a 40k Guardian LP model 0049922 Ser. 4134021 with 3.9L engine. I purchased it used from an individual who had service contract. I had Generac dealer who originally installed and serviced it install for me with new automatic transfer switch. It started ran and tested ok. They said it needed a new onboard battery charger which they ordered for me and I installed. They came back out to check it out after I told them it wouldn't start. The tech said the sensor on the flywheel was bad and he replaced it. We were getting a flashing overspeed led on the board. He tested a few things and said it had to be the PCB Ignition module which I ordered and replaced. It seemed to start every time the first few times I started it. Then it would turn over but not crank and give me the overspeed flashing led. Also it never has attempted to go through the repeated starting cycle when it failed to start the first try. I also replaced the fuel regulator assembly because when it did start it surged high and low. After new fuel regulator it ran smooth. The tech said it could also be the control board but I didn't want to spend any more money until I was certain. I have a volt and ohm meter and I am good at following instructions. Any coaching would be greatly appreciated. Thanks. Gary
Chris
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Mon Feb 11, 2019 5:27 pm

Just to try and clarify, was the Overspeed light flashing before or after the flywheel mag pickup was replaced? A flashing Overspeed light is basically the generator's way of communicating that there is a problem with engine cranking, or stalling (or could also be a bad PCB, wiring, or mag pickup as he mentioned)

If the Overspeed happened after the mag pickup was replaced, I would think it was installed wrong or was damaged by the flywheel.

The mag pickup feeds a signal into the ignition module on that unit, so that is also likely bad if the rest has been already gone through, but you mentioned that it was already replaced. I've heard that the capacitors will blow out on the ign modules if the diode is bad that protects field voltage from going back into the 12V circuit (a replaceable part which can be tested). You may want to have a close look at the old one and the new one to see if the capacitor looks like it has a little blow hole in it. Or post some pictures up here.
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g&bporcelain
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Mon Feb 11, 2019 6:41 pm

The overspeed led was flashing before he replaced the flywheel sensor and he did try 2 different ones and did explain about how the flywheel could hit the tip if it was seated too far. The light still flashed after he replaced it. That's when he told me to replace the PCB ignition module which I did. It seems to be erratic. It wouldn't crank yesterday or earlier today after at least 5 separate tries (the repeat cycle does not work only w one start per manual button push).
I went out a few minutes ago to get a pic of the control board. Tried it and it started 4 times and every time ran fine . I put it on auto and set exercise time to check in 7 days to see if it gives overspeed flashing light again. Could the control board have an erratic issue in it?
Chris
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Mon Feb 11, 2019 8:08 pm

It could certainly have an issue as well. It's hard to troubleshoot random issues like this, but like I said, I'd check that diode and look for issues with the ignition module that you removed and the one that's in there.
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g&bporcelain
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Tue Feb 12, 2019 12:28 pm

How many turns does the mag on the flywheel need to be backed out after I screw it down to touch the teeth on the flywheel?
Chris
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Tue Feb 12, 2019 1:11 pm

Once seated on the TOP of a tooth (make sure the tooth is centered in the opening for the pickup) a good starting point is 1.5 turns out.
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g&bporcelain
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Tue Feb 12, 2019 2:35 pm

Also where is this diode you are referring to and how do I test it? Thanks
Chris
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Tue Feb 12, 2019 2:44 pm

You'll need a digital meter with a diode test function on it. The owner's manual from the meter should give you some instruction on what to look for when testing a diode, but basically when connecting the leads one way you'll have voltage and the other you won't. A diode blocks voltage in one direction.
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g&bporcelain
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Tue Feb 12, 2019 3:52 pm

Where is this diode? Is it next to the PCB mounted on wall beside it (gold colored ?)
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Tue Feb 12, 2019 5:11 pm

Yea, should be on its own L bracket.
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